250601.3 · 62cafa2367d87dc70c215e3e3d22118d1a6ddf3d
Update jq documentation for jq 1.8.0 release (#3333)
reading declarations
docs/content/download/default.yml
@@ -32,6 +32,13 @@ body: * jq is in the official [Arch](https://archlinux.org/packages/?q=jq) repository. Install using `sudo pacman -S jq`. + * jq 1.8.0 binaries for+ [AMD64](https://github.com/jqlang/jq/releases/download/jq-1.8.0/jq-linux-amd64)+ or+ [ARM64](https://github.com/jqlang/jq/releases/download/jq-1.8.0/jq-linux-arm64)+ or+ [i386](https://github.com/jqlang/jq/releases/download/jq-1.8.0/jq-linux-i386).+ * jq 1.7.1 binaries for [AMD64](https://github.com/jqlang/jq/releases/download/jq-1.7.1/jq-linux-amd64) or@@ -74,15 +81,20 @@ body: * Use [Fink](https://finkproject.org) to install jq with `fink install jq`. + * jq 1.8.0 binaries for+ [Apple Silicon](https://github.com/jqlang/jq/releases/download/jq-1.8.0/jq-macos-arm64)+ or+ [Intel Mac](https://github.com/jqlang/jq/releases/download/jq-1.8.0/jq-macos-amd64).+ * jq 1.7.1 binaries for- [AMD64](https://github.com/jqlang/jq/releases/download/jq-1.7.1/jq-macos-amd64)+ [Apple Silicon](https://github.com/jqlang/jq/releases/download/jq-1.7.1/jq-macos-arm64) or- [ARM64](https://github.com/jqlang/jq/releases/download/jq-1.7.1/jq-macos-arm64).+ [Intel Mac](https://github.com/jqlang/jq/releases/download/jq-1.7.1/jq-macos-amd64). * jq 1.7 binaries for- [AMD64](https://github.com/jqlang/jq/releases/download/jq-1.7/jq-macos-amd64)+ [Apple Silicon](https://github.com/jqlang/jq/releases/download/jq-1.7/jq-macos-arm64) or- [ARM64](https://github.com/jqlang/jq/releases/download/jq-1.7/jq-macos-arm64).+ [Intel Mac](https://github.com/jqlang/jq/releases/download/jq-1.7/jq-macos-amd64). * jq 1.6 binary for [AMD64](https://github.com/jqlang/jq/releases/download/jq-1.6/jq-osx-amd64).@@ -130,6 +142,11 @@ body: * Use [Chocolatey NuGet](https://chocolatey.org/) to install jq with `choco install jq`. + * jq 1.8.0 executables for+ [AMD64](https://github.com/jqlang/jq/releases/download/jq-1.8.0/jq-windows-amd64.exe)+ or+ [i386](https://github.com/jqlang/jq/releases/download/jq-1.8.0/jq-windows-i386.exe).+ * jq 1.7.1 executables for [AMD64](https://github.com/jqlang/jq/releases/download/jq-1.7.1/jq-windows-amd64.exe) or@@ -163,8 +180,8 @@ body: ### Checksums and signatures SHA-256 checksums are provided for all release and pre-release binaries.- They can be found under- [sig/v1.x/sha256sum.txt](https://github.com/jqlang/jq/tree/master/sig).+ The checksums for jq 1.8.0 are in+ [sig/v1.8.0/sha256sum.txt](https://raw.githubusercontent.com/jqlang/jq/master/sig/v1.8.0/sha256sum.txt). The checksums for jq 1.7.1 are in [sig/v1.7.1/sha256sum.txt](https://raw.githubusercontent.com/jqlang/jq/master/sig/v1.7.1/sha256sum.txt). The checksums for jq 1.7 are in@@ -175,8 +192,8 @@ body: [sig/v1.5/sha256sum.txt](https://raw.githubusercontent.com/jqlang/jq/master/sig/v1.5/sha256sum.txt). Additionally, all release artifacts are signed by a jq release key. We have two release keys, [one for 1.6 and older releases](https://raw.githubusercontent.com/jqlang/jq/master/sig/jq-release-old.key), and [one for 1.7 and newer releases](https://raw.githubusercontent.com/jqlang/jq/master/sig/jq-release-new.key).- Signatures can be found under- [sig/v1.x/\*.asc](https://github.com/jqlang/jq/tree/master/sig).+ The signatures for jq 1.8.0 are in+ [sig/v1.8.0/\*.asc](https://github.com/jqlang/jq/tree/master/sig/v1.8.0). The signatures for jq 1.7.1 are in [sig/v1.7.1/\*.asc](https://github.com/jqlang/jq/tree/master/sig/v1.7.1). The signatures for jq 1.7 are in@@ -190,6 +207,7 @@ body: ### From source on Linux, macOS, Cygwin, and other POSIX-like operating systems + * [Source tarball for jq 1.8.0](https://github.com/jqlang/jq/releases/download/jq-1.8.0/jq-1.8.0.tar.gz) * [Source tarball for jq 1.7.1](https://github.com/jqlang/jq/releases/download/jq-1.7.1/jq-1.7.1.tar.gz) * [Source tarball for jq 1.7](https://github.com/jqlang/jq/releases/download/jq-1.7/jq-1.7.tar.gz) * [Source tarball for jq 1.6](https://github.com/jqlang/jq/releases/download/jq-1.6/jq-1.6.tar.gz)
@@ -32,6 +32,10 @@ tail: | on [Libera.Chat](https://libera.chat/). For more interactive discussions, feel free to join our [Discord server](https://discord.gg/yg6yjNmgAC). news:+ - date: 1 June 2025+ body: |+ jq 1.8.0 released. See [release notes](https://github.com/jqlang/jq/releases/tag/jq-1.8.0) for details.+ - date: 13 December 2023 body: | jq 1.7.1 released. Security (CVE-2023-50246, CVE-2023-50268) and bug fixes.
docs/content/manual/manual.yml
@@ -1 +1 @@-v1.7/manual.yml+v1.8/manual.yml
docs/content/manual/v1.8/manual.yml
@@ -0,0 +1,3858 @@+---+headline: jq 1.8 Manual++body: |++ A jq program is a "filter": it takes an input, and produces an+ output. There are a lot of builtin filters for extracting a+ particular field of an object, or converting a number to a string,+ or various other standard tasks.++ Filters can be combined in various ways - you can pipe the output of+ one filter into another filter, or collect the output of a filter+ into an array.++ Some filters produce multiple results, for instance there's one that+ produces all the elements of its input array. Piping that filter+ into a second runs the second filter for each element of the+ array. Generally, things that would be done with loops and iteration+ in other languages are just done by gluing filters together in jq.++ It's important to remember that every filter has an input and an+ output. Even literals like "hello" or 42 are filters - they take an+ input but always produce the same literal as output. Operations that+ combine two filters, like addition, generally feed the same input to+ both and combine the results. So, you can implement an averaging+ filter as `add / length` - feeding the input array both to the `add`+ filter and the `length` filter and then performing the division.++ But that's getting ahead of ourselves. :) Let's start with something+ simpler:++manpage_intro: |+ jq(1) -- Command-line JSON processor+ ====================================++ ## SYNOPSIS++ `jq` [<options>...] <filter> [<files>...]++ `jq` can transform JSON in various ways, by selecting, iterating,+ reducing and otherwise mangling JSON documents. For instance,+ running the command `jq 'map(.price) | add'` will take an array of+ JSON objects as input and return the sum of their "price" fields.++ `jq` can accept text input as well, but by default, `jq` reads a+ stream of JSON entities (including numbers and other literals) from+ `stdin`. Whitespace is only needed to separate entities such as 1+ and 2, and true and false. One or more <files> may be specified, in+ which case `jq` will read input from those instead.++ The <options> are described in the [INVOKING JQ] section; they+ mostly concern input and output formatting. The <filter> is written+ in the jq language and specifies how to transform the input+ file or document.++ ## FILTERS++manpage_epilogue: |+ ## BUGS++ Presumably. Report them or discuss them at:++ https://github.com/jqlang/jq/issues++ ## AUTHOR++ Stephen Dolan `<mu@netsoc.tcd.ie>`++sections:+ - title: Invoking jq+ body: |++ jq filters run on a stream of JSON data. The input to jq is+ parsed as a sequence of whitespace-separated JSON values which+ are passed through the provided filter one at a time. The+ output(s) of the filter are written to standard output, as a+ sequence of newline-separated JSON data.++ The simplest and most common filter (or jq program) is `.`,+ which is the identity operator, copying the inputs of the jq+ processor to the output stream. Because the default behavior of+ the jq processor is to read JSON texts from the input stream,+ and to pretty-print outputs, the `.` program's main use is to+ validate and pretty-print the inputs. The jq programming+ language is quite rich and allows for much more than just+ validation and pretty-printing.++ Note: it is important to mind the shell's quoting rules. As a+ general rule it's best to always quote (with single-quote+ characters on Unix shells) the jq program, as too many characters with special+ meaning to jq are also shell meta-characters. For example, `jq+ "foo"` will fail on most Unix shells because that will be the same+ as `jq foo`, which will generally fail because `foo is not+ defined`. When using the Windows command shell (cmd.exe) it's+ best to use double quotes around your jq program when given on the+ command-line (instead of the `-f program-file` option), but then+ double-quotes in the jq program need backslash escaping. When using+ the Powershell (`powershell.exe`) or the Powershell Core+ (`pwsh`/`pwsh.exe`), use single-quote characters around the jq+ program and backslash-escaped double-quotes (`\"`) inside the jq+ program.++ * Unix shells: `jq '.["foo"]'`+ * Powershell: `jq '.[\"foo\"]'`+ * Windows command shell: `jq ".[\"foo\"]"`++ Note: jq allows user-defined functions, but every jq program+ must have a top-level expression.++ You can affect how jq reads and writes its input and output+ using some command-line options:++ * `--null-input` / `-n`:++ Don't read any input at all. Instead, the filter is run once+ using `null` as the input. This is useful when using jq as a+ simple calculator or to construct JSON data from scratch.++ * `--raw-input` / `-R`:++ Don't parse the input as JSON. Instead, each line of text is+ passed to the filter as a string. If combined with `--slurp`,+ then the entire input is passed to the filter as a single long+ string.++ * `--slurp` / `-s`:++ Instead of running the filter for each JSON object in the+ input, read the entire input stream into a large array and run+ the filter just once.++ * `--compact-output` / `-c`:++ By default, jq pretty-prints JSON output. Using this option+ will result in more compact output by instead putting each+ JSON object on a single line.++ * `--raw-output` / `-r`:++ With this option, if the filter's result is a string then it+ will be written directly to standard output rather than being+ formatted as a JSON string with quotes. This can be useful for+ making jq filters talk to non-JSON-based systems.++ * `--raw-output0`:++ Like `-r` but jq will print NUL instead of newline after each output.+ This can be useful when the values being output can contain newlines.+ When the output value contains NUL, jq exits with non-zero code.++ * `--join-output` / `-j`:++ Like `-r` but jq won't print a newline after each output.++ * `--ascii-output` / `-a`:++ jq usually outputs non-ASCII Unicode codepoints as UTF-8, even+ if the input specified them as escape sequences (like+ "\u03bc"). Using this option, you can force jq to produce pure+ ASCII output with every non-ASCII character replaced with the+ equivalent escape sequence.++ * `--sort-keys` / `-S`:++ Output the fields of each object with the keys in sorted order.++ * `--color-output` / `-C` and `--monochrome-output` / `-M`:++ By default, jq outputs colored JSON if writing to a+ terminal. You can force it to produce color even if writing to+ a pipe or a file using `-C`, and disable color with `-M`.+ When the `NO_COLOR` environment variable is not empty, jq disables+ colored output by default, but you can enable it by `-C`.++ Colors can be configured with the `JQ_COLORS` environment+ variable (see below).++ * `--tab`:++ Use a tab for each indentation level instead of two spaces.++ * `--indent n`:++ Use the given number of spaces (no more than 7) for indentation.++ * `--unbuffered`:++ Flush the output after each JSON object is printed (useful if+ you're piping a slow data source into jq and piping jq's+ output elsewhere).++ * `--stream`:++ Parse the input in streaming fashion, outputting arrays of path+ and leaf values (scalars and empty arrays or empty objects).+ For example, `"a"` becomes `[[],"a"]`, and `[[],"a",["b"]]`+ becomes `[[0],[]]`, `[[1],"a"]`, and `[[2,0],"b"]`.++ This is useful for processing very large inputs. Use this in+ conjunction with filtering and the `reduce` and `foreach` syntax+ to reduce large inputs incrementally.++ * `--stream-errors`:++ Like `--stream`, but invalid JSON inputs yield array values+ where the first element is the error and the second is a path.+ For example, `["a",n]` produces `["Invalid literal at line 1,+ column 7",[1]]`.++ Implies `--stream`. Invalid JSON inputs produce no error values+ when `--stream` without `--stream-errors`.++ * `--seq`:++ Use the `application/json-seq` MIME type scheme for separating+ JSON texts in jq's input and output. This means that an ASCII+ RS (record separator) character is printed before each value on+ output and an ASCII LF (line feed) is printed after every+ output. Input JSON texts that fail to parse are ignored (but+ warned about), discarding all subsequent input until the next+ RS. This mode also parses the output of jq without the `--seq`+ option.++ * `-f` / `--from-file`:++ Read the filter from a file rather than from a command line,+ like awk's -f option. This changes the filter argument to be+ interpreted as a filename, instead of the source of a program.++ * `-L directory` / `--library-path directory`:++ Prepend `directory` to the search list for modules. If this+ option is used then no builtin search list is used. See the+ section on modules below.++ * `--arg name value`:++ This option passes a value to the jq program as a predefined+ variable. If you run jq with `--arg foo bar`, then `$foo` is+ available in the program and has the value `"bar"`. Note that+ `value` will be treated as a string, so `--arg foo 123` will+ bind `$foo` to `"123"`.++ Named arguments are also available to the jq program as+ `$ARGS.named`. When the name is not a valid identifier, this is+ the only way to access it.++ * `--argjson name JSON-text`:++ This option passes a JSON-encoded value to the jq program as a+ predefined variable. If you run jq with `--argjson foo 123`, then+ `$foo` is available in the program and has the value `123`.++ * `--slurpfile variable-name filename`:++ This option reads all the JSON texts in the named file and binds+ an array of the parsed JSON values to the given global variable.+ If you run jq with `--slurpfile foo bar`, then `$foo` is available+ in the program and has an array whose elements correspond to the+ texts in the file named `bar`.++ * `--rawfile variable-name filename`:++ This option reads in the named file and binds its contents to the given+ global variable. If you run jq with `--rawfile foo bar`, then `$foo` is+ available in the program and has a string whose contents are to the texts+ in the file named `bar`.++ * `--args`:++ Remaining arguments are positional string arguments. These are+ available to the jq program as `$ARGS.positional[]`.++ * `--jsonargs`:++ Remaining arguments are positional JSON text arguments. These+ are available to the jq program as `$ARGS.positional[]`.++ * `--exit-status` / `-e`:++ Sets the exit status of jq to 0 if the last output value was+ neither `false` nor `null`, 1 if the last output value was+ either `false` or `null`, or 4 if no valid result was ever+ produced. Normally jq exits with 2 if there was any usage+ problem or system error, 3 if there was a jq program compile+ error, or 0 if the jq program ran.++ Another way to set the exit status is with the `halt_error`+ builtin function.++ * `--binary` / `-b`:++ Windows users using WSL, MSYS2, or Cygwin, should use this option+ when using a native jq.exe, otherwise jq will turn newlines (LFs)+ into carriage-return-then-newline (CRLF).++ * `--version` / `-V`:++ Output the jq version and exit with zero.++ * `--build-configuration`:++ Output the build configuration of jq and exit with zero.+ This output has no supported format or structure and may change+ without notice in future releases.++ * `--help` / `-h`:++ Output the jq help and exit with zero.++ * `--`:++ Terminates argument processing. Remaining arguments are not+ interpreted as options.++ * `--run-tests [filename]`:++ Runs the tests in the given file or standard input. This must+ be the last option given and does not honor all preceding+ options. The input consists of comment lines, empty lines, and+ program lines followed by one input line, as many lines of+ output as are expected (one per output), and a terminating empty+ line. Compilation failure tests start with a line containing+ only `%%FAIL`, then a line containing the program to compile,+ then a line containing an error message to compare to the+ actual.++ Be warned that this option can change backwards-incompatibly.++ - title: Basic filters+ entries:+ - title: "Identity: `.`"+ body: |++ The absolute simplest filter is `.` . This filter takes its+ input and produces the same value as output. That is, this+ is the identity operator.++ Since jq by default pretty-prints all output, a trivial+ program consisting of nothing but `.` can be used to format+ JSON output from, say, `curl`.++ Although the identity filter never modifies the value of its+ input, jq processing can sometimes make it appear as though+ it does. For example, using the current implementation of+ jq, we would see that the expression:++ 1E1234567890 | .++ produces `1.7976931348623157e+308` on at least one platform.+ This is because, in the process of parsing the number, this+ particular version of jq has converted it to an IEEE754+ double-precision representation, losing precision.++ The way in which jq handles numbers has changed over time+ and further changes are likely within the parameters set by+ the relevant JSON standards. Moreover, build configuration+ options can alter how jq processes numbers.++ The following remarks are therefore offered with the+ understanding that they are intended to be descriptive of the+ current version of jq and should not be interpreted as being+ prescriptive:++ (1) Any arithmetic operation on a number that has not+ already been converted to an IEEE754 double precision+ representation will trigger a conversion to the IEEE754+ representation.++ (2) jq will attempt to maintain the original decimal+ precision of number literals (if the `--disable-decnum`+ build configuration option was not used), but in expressions+ such `1E1234567890`, precision will be lost if the exponent+ is too large.++ (3) Comparisons are carried out using the untruncated+ big decimal representation of numbers if available, as+ illustrated in one of the following examples.++ The examples below use the builtin function `have_decnum` in+ order to demonstrate the expected effects of using / not+ using the `--disable-decnum` build configuration option, and+ also to allow automated tests derived from these examples to+ pass regardless of whether that option is used.++ examples:+ - program: '.'+ input: '"Hello, world!"'+ output: ['"Hello, world!"']++ - program: '.'+ input: '0.12345678901234567890123456789'+ output: ['0.12345678901234567890123456789']++ - program: '[., tojson] == if have_decnum then [12345678909876543212345,"12345678909876543212345"] else [12345678909876543000000,"12345678909876543000000"] end'+ input: '12345678909876543212345'+ output: ['true']++ - program: '[1234567890987654321,-1234567890987654321 | tojson] == if have_decnum then ["1234567890987654321","-1234567890987654321"] else ["1234567890987654400","-1234567890987654400"] end'+ input: 'null'+ output: ['true']++ - program: '. < 0.12345678901234567890123456788'+ input: '0.12345678901234567890123456789'+ output: ['false']++ - program: 'map([., . == 1]) | tojson == if have_decnum then "[[1,true],[1.000,true],[1.0,true],[1.00,true]]" else "[[1,true],[1,true],[1,true],[1,true]]" end'+ input: '[1, 1.000, 1.0, 100e-2]'+ output: ['true']++ - program: '. as $big | [$big, $big + 1] | map(. > 10000000000000000000000000000000) | . == if have_decnum then [true, false] else [false, false] end'+ input: '10000000000000000000000000000001'+ output: ['true']++ - title: "Object Identifier-Index: `.foo`, `.foo.bar`"+ body: |++ The simplest *useful* filter has the form `.foo`. When given a+ JSON object (aka dictionary or hash) as input, `.foo` produces+ the value at the key "foo" if the key is present, or null otherwise.++ A filter of the form `.foo.bar` is equivalent to `.foo | .bar`.++ The `.foo` syntax only works for simple, identifier-like keys, that+ is, keys that are all made of alphanumeric characters and+ underscore, and which do not start with a digit.++ If the key contains special characters or starts with a digit,+ you need to surround it with double quotes like this:+ `."foo$"`, or else `.["foo$"]`.++ For example `.["foo::bar"]` and `.["foo.bar"]` work while+ `.foo::bar` does not.++ examples:+ - program: '.foo'+ input: '{"foo": 42, "bar": "less interesting data"}'+ output: ['42']++ - program: '.foo'+ input: '{"notfoo": true, "alsonotfoo": false}'+ output: ['null']++ - program: '.["foo"]'+ input: '{"foo": 42}'+ output: ['42']++ - title: "Optional Object Identifier-Index: `.foo?`"+ body: |++ Just like `.foo`, but does not output an error when `.` is not an+ object.++ examples:+ - program: '.foo?'+ input: '{"foo": 42, "bar": "less interesting data"}'+ output: ['42']+ - program: '.foo?'+ input: '{"notfoo": true, "alsonotfoo": false}'+ output: ['null']+ - program: '.["foo"]?'+ input: '{"foo": 42}'+ output: ['42']+ - program: '[.foo?]'+ input: '[1,2]'+ output: ['[]']++ - title: "Object Index: `.[<string>]`"+ body: |++ You can also look up fields of an object using syntax like+ `.["foo"]` (`.foo` above is a shorthand version of this, but+ only for identifier-like strings).++ - title: "Array Index: `.[<number>]`"+ body: |++ When the index value is an integer, `.[<number>]` can index+ arrays. Arrays are zero-based, so `.[2]` returns the third+ element.++ Negative indices are allowed, with -1 referring to the last+ element, -2 referring to the next to last element, and so on.++ examples:+ - program: '.[0]'+ input: '[{"name":"JSON", "good":true}, {"name":"XML", "good":false}]'+ output: ['{"name":"JSON", "good":true}']++ - program: '.[2]'+ input: '[{"name":"JSON", "good":true}, {"name":"XML", "good":false}]'+ output: ['null']++ - program: '.[-2]'+ input: '[1,2,3]'+ output: ['2']++ - title: "Array/String Slice: `.[<number>:<number>]`"+ body: |++ The `.[<number>:<number>]` syntax can be used to return a+ subarray of an array or substring of a string. The array+ returned by `.[10:15]` will be of length 5, containing the+ elements from index 10 (inclusive) to index 15 (exclusive).+ Either index may be negative (in which case it counts+ backwards from the end of the array), or omitted (in which+ case it refers to the start or end of the array).+ Indices are zero-based.++ examples:+ - program: '.[2:4]'+ input: '["a","b","c","d","e"]'+ output: ['["c", "d"]']++ - program: '.[2:4]'+ input: '"abcdefghi"'+ output: ['"cd"']++ - program: '.[:3]'+ input: '["a","b","c","d","e"]'+ output: ['["a", "b", "c"]']++ - program: '.[-2:]'+ input: '["a","b","c","d","e"]'+ output: ['["d", "e"]']++ - title: "Array/Object Value Iterator: `.[]`"+ body: |++ If you use the `.[index]` syntax, but omit the index+ entirely, it will return *all* of the elements of an+ array. Running `.[]` with the input `[1,2,3]` will produce the+ numbers as three separate results, rather than as a single+ array. A filter of the form `.foo[]` is equivalent to+ `.foo | .[]`.++ You can also use this on an object, and it will return all+ the values of the object.++ Note that the iterator operator is a generator of values.++ examples:+ - program: '.[]'+ input: '[{"name":"JSON", "good":true}, {"name":"XML", "good":false}]'+ output:+ - '{"name":"JSON", "good":true}'+ - '{"name":"XML", "good":false}'++ - program: '.[]'+ input: '[]'+ output: []++ - program: '.foo[]'+ input: '{"foo":[1,2,3]}'+ output: ['1','2','3']++ - program: '.[]'+ input: '{"a": 1, "b": 1}'+ output: ['1', '1']++ - title: "`.[]?`"+ body: |++ Like `.[]`, but no errors will be output if . is not an array+ or object. A filter of the form `.foo[]?` is equivalent to+ `.foo | .[]?`.++ - title: "Comma: `,`"+ body: |++ If two filters are separated by a comma, then the+ same input will be fed into both and the two filters' output+ value streams will be concatenated in order: first, all of the+ outputs produced by the left expression, and then all of the+ outputs produced by the right. For instance, filter `.foo,+ .bar`, produces both the "foo" fields and "bar" fields as+ separate outputs.++ The `,` operator is one way to construct generators.++ examples:+ - program: '.foo, .bar'+ input: '{"foo": 42, "bar": "something else", "baz": true}'+ output: ['42', '"something else"']++ - program: ".user, .projects[]"+ input: '{"user":"stedolan", "projects": ["jq", "wikiflow"]}'+ output: ['"stedolan"', '"jq"', '"wikiflow"']++ - program: '.[4,2]'+ input: '["a","b","c","d","e"]'+ output: ['"e"', '"c"']++ - title: "Pipe: `|`"+ body: |++ The | operator combines two filters by feeding the output(s) of+ the one on the left into the input of the one on the right. It's+ similar to the Unix shell's pipe, if you're used to that.++ If the one on the left produces multiple results, the one on+ the right will be run for each of those results. So, the+ expression `.[] | .foo` retrieves the "foo" field of each+ element of the input array. This is a cartesian product,+ which can be surprising.++ Note that `.a.b.c` is the same as `.a | .b | .c`.++ Note too that `.` is the input value at the particular stage+ in a "pipeline", specifically: where the `.` expression appears.+ Thus `.a | . | .b` is the same as `.a.b`, as the `.` in the+ middle refers to whatever value `.a` produced.++ examples:+ - program: '.[] | .name'+ input: '[{"name":"JSON", "good":true}, {"name":"XML", "good":false}]'+ output: ['"JSON"', '"XML"']++ - title: "Parenthesis"+ body: |++ Parenthesis work as a grouping operator just as in any typical+ programming language.++ examples:+ - program: '(. + 2) * 5'+ input: '1'+ output: ['15']++ - title: Types and Values+ body: |++ jq supports the same set of datatypes as JSON - numbers,+ strings, booleans, arrays, objects (which in JSON-speak are+ hashes with only string keys), and "null".++ Booleans, null, strings and numbers are written the same way as+ in JSON. Just like everything else in jq, these simple+ values take an input and produce an output - `42` is a valid jq+ expression that takes an input, ignores it, and returns 42+ instead.++ Numbers in jq are internally represented by their IEEE754 double+ precision approximation. Any arithmetic operation with numbers,+ whether they are literals or results of previous filters, will+ produce a double precision floating point result.++ However, when parsing a literal jq will store the original literal+ string. If no mutation is applied to this value then it will make+ to the output in its original form, even if conversion to double+ would result in a loss.++ entries:+ - title: "Array construction: `[]`"+ body: |++ As in JSON, `[]` is used to construct arrays, as in+ `[1,2,3]`. The elements of the arrays can be any jq+ expression, including a pipeline. All of the results produced+ by all of the expressions are collected into one big array.+ You can use it to construct an array out of a known quantity+ of values (as in `[.foo, .bar, .baz]`) or to "collect" all the+ results of a filter into an array (as in `[.items[].name]`)++ Once you understand the "," operator, you can look at jq's array+ syntax in a different light: the expression `[1,2,3]` is not using a+ built-in syntax for comma-separated arrays, but is instead applying+ the `[]` operator (collect results) to the expression 1,2,3 (which+ produces three different results).++ If you have a filter `X` that produces four results,+ then the expression `[X]` will produce a single result, an+ array of four elements.++ examples:+ - program: "[.user, .projects[]]"+ input: '{"user":"stedolan", "projects": ["jq", "wikiflow"]}'+ output: ['["stedolan", "jq", "wikiflow"]']+ - program: "[ .[] | . * 2]"+ input: '[1, 2, 3]'+ output: ['[2, 4, 6]']++ - title: "Object Construction: `{}`"+ body: |++ Like JSON, `{}` is for constructing objects (aka+ dictionaries or hashes), as in: `{"a": 42, "b": 17}`.++ If the keys are "identifier-like", then the quotes can be left+ off, as in `{a:42, b:17}`. Variable references as key+ expressions use the value of the variable as the key. Key+ expressions other than constant literals, identifiers, or+ variable references, need to be parenthesized, e.g.,+ `{("a"+"b"):59}`.++ The value can be any expression (although you may need to wrap+ it in parentheses if, for example, it contains colons), which+ gets applied to the {} expression's input (remember, all+ filters have an input and an output).++ {foo: .bar}++ will produce the JSON object `{"foo": 42}` if given the JSON+ object `{"bar":42, "baz":43}` as its input. You can use this+ to select particular fields of an object: if the input is an+ object with "user", "title", "id", and "content" fields and+ you just want "user" and "title", you can write++ {user: .user, title: .title}++ Because that is so common, there's a shortcut syntax for it:+ `{user, title}`.++ If one of the expressions produces multiple results,+ multiple dictionaries will be produced. If the input's++ {"user":"stedolan","titles":["JQ Primer", "More JQ"]}++ then the expression++ {user, title: .titles[]}++ will produce two outputs:++ {"user":"stedolan", "title": "JQ Primer"}+ {"user":"stedolan", "title": "More JQ"}++ Putting parentheses around the key means it will be evaluated as an+ expression. With the same input as above,++ {(.user): .titles}++ produces++ {"stedolan": ["JQ Primer", "More JQ"]}++ Variable references as keys use the value of the variable as+ the key. Without a value then the variable's name becomes the+ key and its value becomes the value,++ "f o o" as $foo | "b a r" as $bar | {$foo, $bar:$foo}++ produces++ {"foo":"f o o","b a r":"f o o"}++ examples:+ - program: '{user, title: .titles[]}'+ input: '{"user":"stedolan","titles":["JQ Primer", "More JQ"]}'+ output:+ - '{"user":"stedolan", "title": "JQ Primer"}'+ - '{"user":"stedolan", "title": "More JQ"}'+ - program: '{(.user): .titles}'+ input: '{"user":"stedolan","titles":["JQ Primer", "More JQ"]}'+ output: ['{"stedolan": ["JQ Primer", "More JQ"]}']++ - title: "Recursive Descent: `..`"+ body: |++ Recursively descends `.`, producing every value. This is the+ same as the zero-argument `recurse` builtin (see below). This+ is intended to resemble the XPath `//` operator. Note that+ `..a` does not work; use `.. | .a` instead. In the example+ below we use `.. | .a?` to find all the values of object keys+ "a" in any object found "below" `.`.++ This is particularly useful in conjunction with `path(EXP)`+ (also see below) and the `?` operator.++ examples:+ - program: '.. | .a?'+ input: '[[{"a":1}]]'+ output: ['1']++ - title: Builtin operators and functions+ body: |++ Some jq operators (for instance, `+`) do different things+ depending on the type of their arguments (arrays, numbers,+ etc.). However, jq never does implicit type conversions. If you+ try to add a string to an object you'll get an error message and+ no result.++ Please note that all numbers are converted to IEEE754 double precision+ floating point representation. Arithmetic and logical operators are working+ with these converted doubles. Results of all such operations are also limited+ to the double precision.++ The only exception to this behaviour of number is a snapshot of original number+ literal. When a number which originally was provided as a literal is never+ mutated until the end of the program then it is printed to the output in its+ original literal form. This also includes cases when the original literal+ would be truncated when converted to the IEEE754 double precision floating point+ number.++ entries:+ - title: "Addition: `+`"+ body: |++ The operator `+` takes two filters, applies them both+ to the same input, and adds the results together. What+ "adding" means depends on the types involved:++ - **Numbers** are added by normal arithmetic.++ - **Arrays** are added by being concatenated into a larger array.++ - **Strings** are added by being joined into a larger string.++ - **Objects** are added by merging, that is, inserting all+ the key-value pairs from both objects into a single+ combined object. If both objects contain a value for the+ same key, the object on the right of the `+` wins. (For+ recursive merge use the `*` operator.)++ `null` can be added to any value, and returns the other+ value unchanged.++ examples:+ - program: '.a + 1'+ input: '{"a": 7}'+ output: ['8']+ - program: '.a + .b'+ input: '{"a": [1,2], "b": [3,4]}'+ output: ['[1,2,3,4]']+ - program: '.a + null'+ input: '{"a": 1}'+ output: ['1']+ - program: '.a + 1'+ input: '{}'+ output: ['1']+ - program: '{a: 1} + {b: 2} + {c: 3} + {a: 42}'+ input: 'null'+ output: ['{"a": 42, "b": 2, "c": 3}']++ - title: "Subtraction: `-`"+ body: |++ As well as normal arithmetic subtraction on numbers, the `-`+ operator can be used on arrays to remove all occurrences of+ the second array's elements from the first array.++ examples:+ - program: '4 - .a'+ input: '{"a":3}'+ output: ['1']+ - program: . - ["xml", "yaml"]+ input: '["xml", "yaml", "json"]'+ output: ['["json"]']++ - title: "Multiplication, division, modulo: `*`, `/`, `%`"+ body: |++ These infix operators behave as expected when given two numbers.+ Division by zero raises an error. `x % y` computes x modulo y.++ Multiplying a string by a number produces the concatenation of+ that string that many times. `"x" * 0` produces `""`.++ Dividing a string by another splits the first using the second+ as separators.++ Multiplying two objects will merge them recursively: this works+ like addition but if both objects contain a value for the+ same key, and the values are objects, the two are merged with+ the same strategy.++ examples:+ - program: '10 / . * 3'+ input: '5'+ output: ['6']+ - program: '. / ", "'+ input: '"a, b,c,d, e"'+ output: ['["a","b,c,d","e"]']+ - program: '{"k": {"a": 1, "b": 2}} * {"k": {"a": 0,"c": 3}}'+ input: 'null'+ output: ['{"k": {"a": 0, "b": 2, "c": 3}}']+ - program: '.[] | (1 / .)?'+ input: '[1,0,-1]'+ output: ['1', '-1']++ - title: "`abs`"+ body: |++ The builtin function `abs` is defined naively as: `if . < 0 then - . else . end`.++ For numeric input, this is the absolute value. See the+ section on the identity filter for the implications of this+ definition for numeric input.++ To compute the absolute value of a number as a floating point number, you may wish use `fabs`.++ examples:+ - program: 'map(abs)'+ input: '[-10, -1.1, -1e-1]'+ output: ['[10,1.1,1e-1]']++ - title: "`length`"+ body: |++ The builtin function `length` gets the length of various+ different types of value:++ - The length of a **string** is the number of Unicode+ codepoints it contains (which will be the same as its+ JSON-encoded length in bytes if it's pure ASCII).++ - The length of a **number** is its absolute value.++ - The length of an **array** is the number of elements.++ - The length of an **object** is the number of key-value pairs.++ - The length of **null** is zero.++ - It is an error to use `length` on a **boolean**.++ examples:+ - program: '.[] | length'+ input: '[[1,2], "string", {"a":2}, null, -5]'+ output: ['2', '6', '1', '0', '5']+++ - title: "`utf8bytelength`"+ body: |++ The builtin function `utf8bytelength` outputs the number of+ bytes used to encode a string in UTF-8.++ examples:+ - program: 'utf8bytelength'+ input: '"\u03bc"'+ output: ['2']++ - title: "`keys`, `keys_unsorted`"+ body: |++ The builtin function `keys`, when given an object, returns+ its keys in an array.++ The keys are sorted "alphabetically", by unicode codepoint+ order. This is not an order that makes particular sense in+ any particular language, but you can count on it being the+ same for any two objects with the same set of keys,+ regardless of locale settings.++ When `keys` is given an array, it returns the valid indices+ for that array: the integers from 0 to length-1.++ The `keys_unsorted` function is just like `keys`, but if+ the input is an object then the keys will not be sorted,+ instead the keys will roughly be in insertion order.++ examples:+ - program: 'keys'+ input: '{"abc": 1, "abcd": 2, "Foo": 3}'+ output: ['["Foo", "abc", "abcd"]']+ - program: 'keys'+ input: '[42,3,35]'+ output: ['[0,1,2]']++ - title: "`has(key)`"+ body: |++ The builtin function `has` returns whether the input object+ has the given key, or the input array has an element at the+ given index.++ `has($key)` has the same effect as checking whether `$key`+ is a member of the array returned by `keys`, although `has`+ will be faster.++ examples:+ - program: 'map(has("foo"))'+ input: '[{"foo": 42}, {}]'+ output: ['[true, false]']+ - program: 'map(has(2))'+ input: '[[0,1], ["a","b","c"]]'+ output: ['[false, true]']++ - title: "`in`"+ body: |++ The builtin function `in` returns whether or not the input key is in the+ given object, or the input index corresponds to an element+ in the given array. It is, essentially, an inversed version+ of `has`.++ examples:+ - program: '.[] | in({"foo": 42})'+ input: '["foo", "bar"]'+ output: ['true', 'false']+ - program: 'map(in([0,1]))'+ input: '[2, 0]'+ output: ['[false, true]']++ - title: "`map(f)`, `map_values(f)`"+ body: |++ For any filter `f`, `map(f)` and `map_values(f)` apply `f`+ to each of the values in the input array or object, that is,+ to the values of `.[]`.++ In the absence of errors, `map(f)` always outputs an array+ whereas `map_values(f)` outputs an array if given an array,+ or an object if given an object.++ When the input to `map_values(f)` is an object, the output+ object has the same keys as the input object except for+ those keys whose values when piped to `f` produce no values+ at all.++ The key difference between `map(f)` and `map_values(f)` is+ that the former simply forms an array from all the values of+ `($x|f)` for each value, `$x`, in the input array or object,+ but `map_values(f)` only uses `first($x|f)`.++ Specifically, for object inputs, `map_values(f)` constructs+ the output object by examining in turn the value of+ `first(.[$k]|f)` for each key, `$k`, of the input. If this+ expression produces no values, then the corresponding key+ will be dropped; otherwise, the output object will have that+ value at the key, `$k`.++ Here are some examples to clarify the behavior of `map` and+ `map_values` when applied to arrays. These examples assume the+ input is `[1]` in all cases:++ map(.+1) #=> [2]+ map(., .) #=> [1,1]+ map(empty) #=> []++ map_values(.+1) #=> [2]+ map_values(., .) #=> [1]+ map_values(empty) #=> []++ `map(f)` is equivalent to `[.[] | f]` and+ `map_values(f)` is equivalent to `.[] |= f`.++ In fact, these are their implementations.+++ examples:+ - program: 'map(.+1)'+ input: '[1,2,3]'+ output: ['[2,3,4]']++ - program: 'map_values(.+1)'+ input: '{"a": 1, "b": 2, "c": 3}'+ output: ['{"a": 2, "b": 3, "c": 4}']++ - program: 'map(., .)'+ input: '[1,2]'+ output: ['[1,1,2,2]']++ - program: 'map_values(. // empty)'+ input: '{"a": null, "b": true, "c": false}'+ output: ['{"b":true}']+++ - title: "`pick(pathexps)`"+ body: |++ Emit the projection of the input object or array defined by the+ specified sequence of path expressions, such that if `p` is any+ one of these specifications, then `(. | p)` will evaluate to the+ same value as `(. | pick(pathexps) | p)`. For arrays, negative+ indices and `.[m:n]` specifications should not be used.++ examples:+ - program: 'pick(.a, .b.c, .x)'+ input: '{"a": 1, "b": {"c": 2, "d": 3}, "e": 4}'+ output: ['{"a":1,"b":{"c":2},"x":null}']++ - program: 'pick(.[2], .[0], .[0])'+ input: '[1,2,3,4]'+ output: ['[1,null,3]']+++ - title: "`path(path_expression)`"+ body: |++ Outputs array representations of the given path expression+ in `.`. The outputs are arrays of strings (object keys)+ and/or numbers (array indices).++ Path expressions are jq expressions like `.a`, but also `.[]`.+ There are two types of path expressions: ones that can match+ exactly, and ones that cannot. For example, `.a.b.c` is an+ exact match path expression, while `.a[].b` is not.++ `path(exact_path_expression)` will produce the array+ representation of the path expression even if it does not+ exist in `.`, if `.` is `null` or an array or an object.++ `path(pattern)` will produce array representations of the+ paths matching `pattern` if the paths exist in `.`.++ Note that the path expressions are not different from normal+ expressions. The expression+ `path(..|select(type=="boolean"))` outputs all the paths to+ boolean values in `.`, and only those paths.++ examples:+ - program: 'path(.a[0].b)'+ input: 'null'+ output: ['["a",0,"b"]']+ - program: '[path(..)]'+ input: '{"a":[{"b":1}]}'+ output: ['[[],["a"],["a",0],["a",0,"b"]]']++ - title: "`del(path_expression)`"+ body: |++ The builtin function `del` removes a key and its corresponding+ value from an object.++ examples:+ - program: 'del(.foo)'+ input: '{"foo": 42, "bar": 9001, "baz": 42}'+ output: ['{"bar": 9001, "baz": 42}']+ - program: 'del(.[1, 2])'+ input: '["foo", "bar", "baz"]'+ output: ['["foo"]']++ - title: "`getpath(PATHS)`"+ body: |++ The builtin function `getpath` outputs the values in `.` found+ at each path in `PATHS`.++ examples:+ - program: 'getpath(["a","b"])'+ input: 'null'+ output: ['null']+ - program: '[getpath(["a","b"], ["a","c"])]'+ input: '{"a":{"b":0, "c":1}}'+ output: ['[0, 1]']++ - title: "`setpath(PATHS; VALUE)`"+ body: |++ The builtin function `setpath` sets the `PATHS` in `.` to `VALUE`.++ examples:+ - program: 'setpath(["a","b"]; 1)'+ input: 'null'+ output: ['{"a": {"b": 1}}']+ - program: 'setpath(["a","b"]; 1)'+ input: '{"a":{"b":0}}'+ output: ['{"a": {"b": 1}}']+ - program: 'setpath([0,"a"]; 1)'+ input: 'null'+ output: ['[{"a":1}]']++ - title: "`delpaths(PATHS)`"+ body: |++ The builtin function `delpaths` deletes the `PATHS` in `.`.+ `PATHS` must be an array of paths, where each path is an array+ of strings and numbers.++ examples:+ - program: 'delpaths([["a","b"]])'+ input: '{"a":{"b":1},"x":{"y":2}}'+ output: ['{"a":{},"x":{"y":2}}']++ - title: "`to_entries`, `from_entries`, `with_entries(f)`"+ body: |++ These functions convert between an object and an array of+ key-value pairs. If `to_entries` is passed an object, then+ for each `k: v` entry in the input, the output array+ includes `{"key": k, "value": v}`.++ `from_entries` does the opposite conversion, and `with_entries(f)`+ is a shorthand for `to_entries | map(f) | from_entries`, useful for+ doing some operation to all keys and values of an object.+ `from_entries` accepts `"key"`, `"Key"`, `"name"`, `"Name"`,+ `"value"`, and `"Value"` as keys.++ examples:+ - program: 'to_entries'+ input: '{"a": 1, "b": 2}'+ output: ['[{"key":"a", "value":1}, {"key":"b", "value":2}]']+ - program: 'from_entries'+ input: '[{"key":"a", "value":1}, {"key":"b", "value":2}]'+ output: ['{"a": 1, "b": 2}']+ - program: 'with_entries(.key |= "KEY_" + .)'+ input: '{"a": 1, "b": 2}'+ output: ['{"KEY_a": 1, "KEY_b": 2}']+++ - title: "`select(boolean_expression)`"+ body: |++ The function `select(f)` produces its input unchanged if+ `f` returns true for that input, and produces no output+ otherwise.++ It's useful for filtering lists: `[1,2,3] | map(select(. >= 2))`+ will give you `[2,3]`.++ examples:+ - program: 'map(select(. >= 2))'+ input: '[1,5,3,0,7]'+ output: ['[5,3,7]']+ - program: '.[] | select(.id == "second")'+ input: '[{"id": "first", "val": 1}, {"id": "second", "val": 2}]'+ output: ['{"id": "second", "val": 2}']+++ - title: "`arrays`, `objects`, `iterables`, `booleans`, `numbers`, `normals`, `finites`, `strings`, `nulls`, `values`, `scalars`"+ body: |++ These built-ins select only inputs that are arrays, objects,+ iterables (arrays or objects), booleans, numbers, normal+ numbers, finite numbers, strings, null, non-null values, and+ non-iterables, respectively.++ examples:+ - program: '.[]|numbers'+ input: '[[],{},1,"foo",null,true,false]'+ output: ['1']++ - title: "`empty`"+ body: |++ `empty` returns no results. None at all. Not even `null`.++ It's useful on occasion. You'll know if you need it :)++ examples:+ - program: '1, empty, 2'+ input: 'null'+ output: ['1', '2']+ - program: '[1,2,empty,3]'+ input: 'null'+ output: ['[1,2,3]']++ - title: "`error`, `error(message)`"+ body: |++ Produces an error with the input value, or with the message+ given as the argument. Errors can be caught with try/catch;+ see below.++ examples:+ - program: 'try error catch .'+ input: '"error message"'+ output: ['"error message"']++ - program: 'try error("invalid value: \(.)") catch .'+ input: '42'+ output: ['"invalid value: 42"']++ - title: "`halt`"+ body: |++ Stops the jq program with no further outputs. jq will exit+ with exit status `0`.++ - title: "`halt_error`, `halt_error(exit_code)`"+ body: |++ Stops the jq program with no further outputs. The input will+ be printed on `stderr` as raw output (i.e., strings will not+ have double quotes) with no decoration, not even a newline.++ The given `exit_code` (defaulting to `5`) will be jq's exit+ status.++ For example, `"Error: something went wrong\n"|halt_error(1)`.++ - title: "`$__loc__`"+ body: |++ Produces an object with a "file" key and a "line" key, with+ the filename and line number where `$__loc__` occurs, as+ values.++ examples:+ - program: 'try error("\($__loc__)") catch .'+ input: 'null'+ output: ['"{\"file\":\"<top-level>\",\"line\":1}"']++ - title: "`paths`, `paths(node_filter)`"+ body: |++ `paths` outputs the paths to all the elements in its input+ (except it does not output the empty list, representing .+ itself).++ `paths(f)` outputs the paths to any values for which `f` is `true`.+ That is, `paths(type == "number")` outputs the paths to all numeric+ values.++ examples:+ - program: '[paths]'+ input: '[1,[[],{"a":2}]]'+ output: ['[[0],[1],[1,0],[1,1],[1,1,"a"]]']+ - program: '[paths(type == "number")]'+ input: '[1,[[],{"a":2}]]'+ output: ['[[0],[1,1,"a"]]']++ - title: "`add`, `add(generator)`"+ body: |++ The filter `add` takes as input an array, and produces as+ output the elements of the array added together. This might+ mean summed, concatenated or merged depending on the types+ of the elements of the input array - the rules are the same+ as those for the `+` operator (described above).++ If the input is an empty array, `add` returns `null`.++ `add(generator)` operates on the given generator rather than+ the input.++ examples:+ - program: add+ input: '["a","b","c"]'+ output: ['"abc"']+ - program: add+ input: '[1, 2, 3]'+ output: ['6']+ - program: add+ input: '[]'+ output: ["null"]+ - program: add(.[].a)+ input: '[{"a":3}, {"a":5}, {"b":6}]'+ output: ['8']++ - title: "`any`, `any(condition)`, `any(generator; condition)`"+ body: |++ The filter `any` takes as input an array of boolean values,+ and produces `true` as output if any of the elements of+ the array are `true`.++ If the input is an empty array, `any` returns `false`.++ The `any(condition)` form applies the given condition to the+ elements of the input array.++ The `any(generator; condition)` form applies the given+ condition to all the outputs of the given generator.++ examples:+ - program: any+ input: '[true, false]'+ output: ["true"]+ - program: any+ input: '[false, false]'+ output: ["false"]+ - program: any+ input: '[]'+ output: ["false"]++ - title: "`all`, `all(condition)`, `all(generator; condition)`"+ body: |++ The filter `all` takes as input an array of boolean values,+ and produces `true` as output if all of the elements of+ the array are `true`.++ The `all(condition)` form applies the given condition to the+ elements of the input array.++ The `all(generator; condition)` form applies the given+ condition to all the outputs of the given generator.++ If the input is an empty array, `all` returns `true`.++ examples:+ - program: all+ input: '[true, false]'+ output: ["false"]+ - program: all+ input: '[true, true]'+ output: ["true"]+ - program: all+ input: '[]'+ output: ["true"]++ - title: "`flatten`, `flatten(depth)`"+ body: |++ The filter `flatten` takes as input an array of nested arrays,+ and produces a flat array in which all arrays inside the original+ array have been recursively replaced by their values. You can pass+ an argument to it to specify how many levels of nesting to flatten.++ `flatten(2)` is like `flatten`, but going only up to two+ levels deep.++ examples:+ - program: flatten+ input: '[1, [2], [[3]]]'+ output: ["[1, 2, 3]"]+ - program: flatten(1)+ input: '[1, [2], [[3]]]'+ output: ["[1, 2, [3]]"]+ - program: flatten+ input: '[[]]'+ output: ["[]"]+ - program: flatten+ input: '[{"foo": "bar"}, [{"foo": "baz"}]]'+ output: ['[{"foo": "bar"}, {"foo": "baz"}]']++ - title: "`range(upto)`, `range(from; upto)`, `range(from; upto; by)`"+ body: |++ The `range` function produces a range of numbers. `range(4; 10)`+ produces 6 numbers, from 4 (inclusive) to 10 (exclusive). The numbers+ are produced as separate outputs. Use `[range(4; 10)]` to get a range as+ an array.++ The one argument form generates numbers from 0 to the given+ number, with an increment of 1.++ The two argument form generates numbers from `from` to `upto`+ with an increment of 1.++ The three argument form generates numbers `from` to `upto`+ with an increment of `by`.++ examples:+ - program: 'range(2; 4)'+ input: 'null'+ output: ['2', '3']+ - program: '[range(2; 4)]'+ input: 'null'+ output: ['[2,3]']+ - program: '[range(4)]'+ input: 'null'+ output: ['[0,1,2,3]']+ - program: '[range(0; 10; 3)]'+ input: 'null'+ output: ['[0,3,6,9]']+ - program: '[range(0; 10; -1)]'+ input: 'null'+ output: ['[]']+ - program: '[range(0; -5; -1)]'+ input: 'null'+ output: ['[0,-1,-2,-3,-4]']++ - title: "`floor`"+ body: |++ The `floor` function returns the floor of its numeric input.++ examples:+ - program: 'floor'+ input: '3.14159'+ output: ['3']++ - title: "`sqrt`"+ body: |++ The `sqrt` function returns the square root of its numeric input.++ examples:+ - program: 'sqrt'+ input: '9'+ output: ['3']++ - title: "`tonumber`"+ body: |++ The `tonumber` function parses its input as a number. It+ will convert correctly-formatted strings to their numeric+ equivalent, leave numbers alone, and give an error on all other input.++ examples:+ - program: '.[] | tonumber'+ input: '[1, "1"]'+ output: ['1', '1']++ - title: "`toboolean`"+ body: |++ The `toboolean` function parses its input as a boolean. It+ will convert correctly-formatted strings to their boolean+ equivalent, leave booleans alone, and give an error on all other input.++ examples:+ - program: '.[] | toboolean'+ input: '["true", "false", true, false]'+ output: ['true', 'false', 'true', 'false']++ - title: "`tostring`"+ body: |++ The `tostring` function prints its input as a+ string. Strings are left unchanged, and all other values are+ JSON-encoded.++ examples:+ - program: '.[] | tostring'+ input: '[1, "1", [1]]'+ output: ['"1"', '"1"', '"[1]"']++ - title: "`type`"+ body: |++ The `type` function returns the type of its argument as a+ string, which is one of null, boolean, number, string, array+ or object.++ examples:+ - program: 'map(type)'+ input: '[0, false, [], {}, null, "hello"]'+ output: ['["number", "boolean", "array", "object", "null", "string"]']++ - title: "`infinite`, `nan`, `isinfinite`, `isnan`, `isfinite`, `isnormal`"+ body: |++ Some arithmetic operations can yield infinities and "not a+ number" (NaN) values. The `isinfinite` builtin returns `true`+ if its input is infinite. The `isnan` builtin returns `true`+ if its input is a NaN. The `infinite` builtin returns a+ positive infinite value. The `nan` builtin returns a NaN.+ The `isnormal` builtin returns true if its input is a normal+ number.++ Note that division by zero raises an error.++ Currently most arithmetic operations operating on infinities,+ NaNs, and sub-normals do not raise errors.++ examples:+ - program: '.[] | (infinite * .) < 0'+ input: '[-1, 1]'+ output: ['true', 'false']+ - program: 'infinite, nan | type'+ input: 'null'+ output: ['"number"', '"number"']++ - title: "`sort`, `sort_by(path_expression)`"+ body: |++ The `sort` functions sorts its input, which must be an+ array. Values are sorted in the following order:++ * `null`+ * `false`+ * `true`+ * numbers+ * strings, in alphabetical order (by unicode codepoint value)+ * arrays, in lexical order+ * objects++ The ordering for objects is a little complex: first they're+ compared by comparing their sets of keys (as arrays in+ sorted order), and if their keys are equal then the values+ are compared key by key.++ `sort_by` may be used to sort by a particular field of an+ object, or by applying any jq filter. `sort_by(f)` compares+ two elements by comparing the result of `f` on each element.+ When `f` produces multiple values, it firstly compares the+ first values, and the second values if the first values are+ equal, and so on.++ examples:+ - program: 'sort'+ input: '[8,3,null,6]'+ output: ['[null,3,6,8]']++ - program: 'sort_by(.foo)'+ input: '[{"foo":4, "bar":10}, {"foo":3, "bar":10}, {"foo":2, "bar":1}]'+ output: ['[{"foo":2, "bar":1}, {"foo":3, "bar":10}, {"foo":4, "bar":10}]']++ - program: 'sort_by(.foo, .bar)'+ input: '[{"foo":4, "bar":10}, {"foo":3, "bar":20}, {"foo":2, "bar":1}, {"foo":3, "bar":10}]'+ output: ['[{"foo":2, "bar":1}, {"foo":3, "bar":10}, {"foo":3, "bar":20}, {"foo":4, "bar":10}]']++ - title: "`group_by(path_expression)`"+ body: |++ `group_by(.foo)` takes as input an array, groups the+ elements having the same `.foo` field into separate arrays,+ and produces all of these arrays as elements of a larger+ array, sorted by the value of the `.foo` field.++ Any jq expression, not just a field access, may be used in+ place of `.foo`. The sorting order is the same as described+ in the `sort` function above.++ examples:+ - program: 'group_by(.foo)'+ input: '[{"foo":1, "bar":10}, {"foo":3, "bar":100}, {"foo":1, "bar":1}]'+ output: ['[[{"foo":1, "bar":10}, {"foo":1, "bar":1}], [{"foo":3, "bar":100}]]']++ - title: "`min`, `max`, `min_by(path_exp)`, `max_by(path_exp)`"+ body: |++ Find the minimum or maximum element of the input array.++ The `min_by(path_exp)` and `max_by(path_exp)` functions allow+ you to specify a particular field or property to examine, e.g.+ `min_by(.foo)` finds the object with the smallest `foo` field.++ examples:+ - program: 'min'+ input: '[5,4,2,7]'+ output: ['2']+ - program: 'max_by(.foo)'+ input: '[{"foo":1, "bar":14}, {"foo":2, "bar":3}]'+ output: ['{"foo":2, "bar":3}']++ - title: "`unique`, `unique_by(path_exp)`"+ body: |++ The `unique` function takes as input an array and produces+ an array of the same elements, in sorted order, with+ duplicates removed.++ The `unique_by(path_exp)` function will keep only one element+ for each value obtained by applying the argument. Think of it+ as making an array by taking one element out of every group+ produced by `group`.++ examples:+ - program: 'unique'+ input: '[1,2,5,3,5,3,1,3]'+ output: ['[1,2,3,5]']+ - program: 'unique_by(.foo)'+ input: '[{"foo": 1, "bar": 2}, {"foo": 1, "bar": 3}, {"foo": 4, "bar": 5}]'+ output: ['[{"foo": 1, "bar": 2}, {"foo": 4, "bar": 5}]']+ - program: 'unique_by(length)'+ input: '["chunky", "bacon", "kitten", "cicada", "asparagus"]'+ output: ['["bacon", "chunky", "asparagus"]']++ - title: "`reverse`"+ body: |++ This function reverses an array.++ examples:+ - program: 'reverse'+ input: '[1,2,3,4]'+ output: ['[4,3,2,1]']++ - title: "`contains(element)`"+ body: |++ The filter `contains(b)` will produce true if b is+ completely contained within the input. A string B is+ contained in a string A if B is a substring of A. An array B+ is contained in an array A if all elements in B are+ contained in any element in A. An object B is contained in+ object A if all of the values in B are contained in the+ value in A with the same key. All other types are assumed to+ be contained in each other if they are equal.++ examples:+ - program: 'contains("bar")'+ input: '"foobar"'+ output: ['true']+ - program: 'contains(["baz", "bar"])'+ input: '["foobar", "foobaz", "blarp"]'+ output: ['true']+ - program: 'contains(["bazzzzz", "bar"])'+ input: '["foobar", "foobaz", "blarp"]'+ output: ['false']+ - program: 'contains({foo: 12, bar: [{barp: 12}]})'+ input: '{"foo": 12, "bar":[1,2,{"barp":12, "blip":13}]}'+ output: ['true']+ - program: 'contains({foo: 12, bar: [{barp: 15}]})'+ input: '{"foo": 12, "bar":[1,2,{"barp":12, "blip":13}]}'+ output: ['false']++ - title: "`indices(s)`"+ body: |++ Outputs an array containing the indices in `.` where `s`+ occurs. The input may be an array, in which case if `s` is an+ array then the indices output will be those where all elements+ in `.` match those of `s`.++ examples:+ - program: 'indices(", ")'+ input: '"a,b, cd, efg, hijk"'+ output: ['[3,7,12]']+ - program: 'indices(1)'+ input: '[0,1,2,1,3,1,4]'+ output: ['[1,3,5]']+ - program: 'indices([1,2])'+ input: '[0,1,2,3,1,4,2,5,1,2,6,7]'+ output: ['[1,8]']++ - title: "`index(s)`, `rindex(s)`"+ body: |++ Outputs the index of the first (`index`) or last (`rindex`)+ occurrence of `s` in the input.++ examples:+ - program: 'index(", ")'+ input: '"a,b, cd, efg, hijk"'+ output: ['3']+ - program: 'index(1)'+ input: '[0,1,2,1,3,1,4]'+ output: ['1']+ - program: 'index([1,2])'+ input: '[0,1,2,3,1,4,2,5,1,2,6,7]'+ output: ['1']+ - program: 'rindex(", ")'+ input: '"a,b, cd, efg, hijk"'+ output: ['12']+ - program: 'rindex(1)'+ input: '[0,1,2,1,3,1,4]'+ output: ['5']+ - program: 'rindex([1,2])'+ input: '[0,1,2,3,1,4,2,5,1,2,6,7]'+ output: ['8']++ - title: "`inside`"+ body: |++ The filter `inside(b)` will produce true if the input is+ completely contained within b. It is, essentially, an+ inversed version of `contains`.++ examples:+ - program: 'inside("foobar")'+ input: '"bar"'+ output: ['true']+ - program: 'inside(["foobar", "foobaz", "blarp"])'+ input: '["baz", "bar"]'+ output: ['true']+ - program: 'inside(["foobar", "foobaz", "blarp"])'+ input: '["bazzzzz", "bar"]'+ output: ['false']+ - program: 'inside({"foo": 12, "bar":[1,2,{"barp":12, "blip":13}]})'+ input: '{"foo": 12, "bar": [{"barp": 12}]}'+ output: ['true']+ - program: 'inside({"foo": 12, "bar":[1,2,{"barp":12, "blip":13}]})'+ input: '{"foo": 12, "bar": [{"barp": 15}]}'+ output: ['false']++ - title: "`startswith(str)`"+ body: |++ Outputs `true` if . starts with the given string argument.++ examples:+ - program: '[.[]|startswith("foo")]'+ input: '["fo", "foo", "barfoo", "foobar", "barfoob"]'+ output: ['[false, true, false, true, false]']++ - title: "`endswith(str)`"+ body: |++ Outputs `true` if . ends with the given string argument.++ examples:+ - program: '[.[]|endswith("foo")]'+ input: '["foobar", "barfoo"]'+ output: ['[false, true]']++ - title: "`combinations`, `combinations(n)`"+ body: |++ Outputs all combinations of the elements of the arrays in the+ input array. If given an argument `n`, it outputs all combinations+ of `n` repetitions of the input array.++ examples:+ - program: 'combinations'+ input: '[[1,2], [3, 4]]'+ output: ['[1, 3]', '[1, 4]', '[2, 3]', '[2, 4]']+ - program: 'combinations(2)'+ input: '[0, 1]'+ output: ['[0, 0]', '[0, 1]', '[1, 0]', '[1, 1]']++ - title: "`ltrimstr(str)`"+ body: |++ Outputs its input with the given prefix string removed, if it+ starts with it.++ examples:+ - program: '[.[]|ltrimstr("foo")]'+ input: '["fo", "foo", "barfoo", "foobar", "afoo"]'+ output: ['["fo","","barfoo","bar","afoo"]']++ - title: "`rtrimstr(str)`"+ body: |++ Outputs its input with the given suffix string removed, if it+ ends with it.++ examples:+ - program: '[.[]|rtrimstr("foo")]'+ input: '["fo", "foo", "barfoo", "foobar", "foob"]'+ output: ['["fo","","bar","foobar","foob"]']++ - title: "`trimstr(str)`"+ body: |++ Outputs its input with the given string removed at both ends, if it+ starts or ends with it.++ examples:+ - program: '[.[]|trimstr("foo")]'+ input: '["fo", "foo", "barfoo", "foobarfoo", "foob"]'+ output: ['["fo","","bar","bar","b"]']++ - title: "`trim`, `ltrim`, `rtrim`"+ body: |++ `trim` trims both leading and trailing whitespace.++ `ltrim` trims only leading (left side) whitespace.++ `rtrim` trims only trailing (right side) whitespace.++ Whitespace characters are the usual `" "`, `"\n"` `"\t"`, `"\r"`+ and also all characters in the Unicode character database with the+ whitespace property. Note that what considers whitespace might+ change in the future.++ examples:+ - program: 'trim, ltrim, rtrim'+ input: '" abc "'+ output: ['"abc"', '"abc "', '" abc"']++ - title: "`explode`"+ body: |++ Converts an input string into an array of the string's+ codepoint numbers.++ examples:+ - program: 'explode'+ input: '"foobar"'+ output: ['[102,111,111,98,97,114]']++ - title: "`implode`"+ body: |++ The inverse of explode.++ examples:+ - program: 'implode'+ input: '[65, 66, 67]'+ output: ['"ABC"']++ - title: "`split(str)`"+ body: |++ Splits an input string on the separator argument.++ `split` can also split on regex matches when called with+ two arguments (see the regular expressions section below).++ examples:+ - program: 'split(", ")'+ input: '"a, b,c,d, e, "'+ output: ['["a","b,c,d","e",""]']++ - title: "`join(str)`"+ body: |++ Joins the array of elements given as input, using the+ argument as separator. It is the inverse of `split`: that is,+ running `split("foo") | join("foo")` over any input string+ returns said input string.++ Numbers and booleans in the input are converted to strings.+ Null values are treated as empty strings. Arrays and objects+ in the input are not supported.++ examples:+ - program: 'join(", ")'+ input: '["a","b,c,d","e"]'+ output: ['"a, b,c,d, e"']+ - program: 'join(" ")'+ input: '["a",1,2.3,true,null,false]'+ output: ['"a 1 2.3 true false"']++ - title: "`ascii_downcase`, `ascii_upcase`"+ body: |++ Emit a copy of the input string with its alphabetic characters (a-z and A-Z)+ converted to the specified case.++ examples:+ - program: 'ascii_upcase'+ input: '"useful but not for é"'+ output: ['"USEFUL BUT NOT FOR é"']++ - title: "`while(cond; update)`"+ body: |++ The `while(cond; update)` function allows you to repeatedly+ apply an update to `.` until `cond` is false.++ Note that `while(cond; update)` is internally defined as a+ recursive jq function. Recursive calls within `while` will+ not consume additional memory if `update` produces at most one+ output for each input. See advanced topics below.++ examples:+ - program: '[while(.<100; .*2)]'+ input: '1'+ output: ['[1,2,4,8,16,32,64]']++ - title: "`repeat(exp)`"+ body: |++ The `repeat(exp)` function allows you to repeatedly+ apply expression `exp` to `.` until an error is raised.++ Note that `repeat(exp)` is internally defined as a+ recursive jq function. Recursive calls within `repeat` will+ not consume additional memory if `exp` produces at most one+ output for each input. See advanced topics below.++ examples:+ - program: '[repeat(.*2, error)?]'+ input: '1'+ output: ['[2]']++ - title: "`until(cond; next)`"+ body: |++ The `until(cond; next)` function allows you to repeatedly+ apply the expression `next`, initially to `.` then to its own+ output, until `cond` is true. For example, this can be used+ to implement a factorial function (see below).++ Note that `until(cond; next)` is internally defined as a+ recursive jq function. Recursive calls within `until()` will+ not consume additional memory if `next` produces at most one+ output for each input. See advanced topics below.++ examples:+ - program: '[.,1]|until(.[0] < 1; [.[0] - 1, .[1] * .[0]])|.[1]'+ input: '4'+ output: ['24']+++ - title: "`recurse(f)`, `recurse`, `recurse(f; condition)`"+ body: |++ The `recurse(f)` function allows you to search through a+ recursive structure, and extract interesting data from all+ levels. Suppose your input represents a filesystem:++ {"name": "/", "children": [+ {"name": "/bin", "children": [+ {"name": "/bin/ls", "children": []},+ {"name": "/bin/sh", "children": []}]},+ {"name": "/home", "children": [+ {"name": "/home/stephen", "children": [+ {"name": "/home/stephen/jq", "children": []}]}]}]}++ Now suppose you want to extract all of the filenames+ present. You need to retrieve `.name`, `.children[].name`,+ `.children[].children[].name`, and so on. You can do this+ with:++ recurse(.children[]) | .name++ When called without an argument, `recurse` is equivalent to+ `recurse(.[]?)`.++ `recurse(f)` is identical to `recurse(f; true)` and can be+ used without concerns about recursion depth.++ `recurse(f; condition)` is a generator which begins by+ emitting . and then emits in turn .|f, .|f|f, .|f|f|f, ... so long+ as the computed value satisfies the condition. For example,+ to generate all the integers, at least in principle, one+ could write `recurse(.+1; true)`.++ The recursive calls in `recurse` will not consume additional+ memory whenever `f` produces at most a single output for each+ input.++ examples:+ - program: 'recurse(.foo[])'+ input: '{"foo":[{"foo": []}, {"foo":[{"foo":[]}]}]}'+ output:+ - '{"foo":[{"foo":[]},{"foo":[{"foo":[]}]}]}'+ - '{"foo":[]}'+ - '{"foo":[{"foo":[]}]}'+ - '{"foo":[]}'++ - program: 'recurse'+ input: '{"a":0,"b":[1]}'+ output:+ - '{"a":0,"b":[1]}'+ - '0'+ - '[1]'+ - '1'++ - program: 'recurse(. * .; . < 20)'+ input: '2'+ output: ['2', '4', '16']++ - title: "`walk(f)`"+ body: |++ The `walk(f)` function applies f recursively to every+ component of the input entity. When an array is+ encountered, f is first applied to its elements and then to+ the array itself; when an object is encountered, f is first+ applied to all the values and then to the object. In+ practice, f will usually test the type of its input, as+ illustrated in the following examples. The first example+ highlights the usefulness of processing the elements of an+ array of arrays before processing the array itself. The second+ example shows how all the keys of all the objects within the+ input can be considered for alteration.++ examples:+ - program: 'walk(if type == "array" then sort else . end)'+ input: '[[4, 1, 7], [8, 5, 2], [3, 6, 9]]'+ output:+ - '[[1,4,7],[2,5,8],[3,6,9]]'++ - program: 'walk( if type == "object" then with_entries( .key |= sub( "^_+"; "") ) else . end )'+ input: '[ { "_a": { "__b": 2 } } ]'+ output:+ - '[{"a":{"b":2}}]'++ - title: "`have_literal_numbers`"+ body: |++ This builtin returns true if jq's build configuration+ includes support for preservation of input number literals.++ - title: "`have_decnum`"+ body: |++ This builtin returns true if jq was built with "decnum",+ which is the current literal number preserving numeric+ backend implementation for jq.++ - title: "`$JQ_BUILD_CONFIGURATION`"+ body: |++ This builtin binding shows the jq executable's build+ configuration. Its value has no particular format, but+ it can be expected to be at least the `./configure`+ command-line arguments, and may be enriched in the+ future to include the version strings for the build+ tooling used.++ Note that this can be overridden in the command-line+ with `--arg` and related options.++ - title: "`$ENV`, `env`"+ body: |++ `$ENV` is an object representing the environment variables as+ set when the jq program started.++ `env` outputs an object representing jq's current environment.++ At the moment there is no builtin for setting environment+ variables.++ examples:+ - program: '$ENV.PAGER'+ input: 'null'+ output: ['"less"']++ - program: 'env.PAGER'+ input: 'null'+ output: ['"less"']++ - title: "`transpose`"+ body: |++ Transpose a possibly jagged matrix (an array of arrays).+ Rows are padded with nulls so the result is always rectangular.++ examples:+ - program: 'transpose'+ input: '[[1], [2,3]]'+ output: ['[[1,2],[null,3]]']++ - title: "`bsearch(x)`"+ body: |++ `bsearch(x)` conducts a binary search for x in the input+ array. If the input is sorted and contains x, then+ `bsearch(x)` will return its index in the array; otherwise, if+ the array is sorted, it will return (-1 - ix) where ix is an+ insertion point such that the array would still be sorted+ after the insertion of x at ix. If the array is not sorted,+ `bsearch(x)` will return an integer that is probably of no+ interest.++ examples:+ - program: 'bsearch(0)'+ input: '[0,1]'+ output: ['0']+ - program: 'bsearch(0)'+ input: '[1,2,3]'+ output: ['-1']+ - program: 'bsearch(4) as $ix | if $ix < 0 then .[-(1+$ix)] = 4 else . end'+ input: '[1,2,3]'+ output: ['[1,2,3,4]']++ - title: "String interpolation: `\\(exp)`"+ body: |++ Inside a string, you can put an expression inside parens+ after a backslash. Whatever the expression returns will be+ interpolated into the string.++ examples:+ - program: '"The input was \(.), which is one less than \(.+1)"'+ input: '42'+ output: ['"The input was 42, which is one less than 43"']++ - title: "Convert to/from JSON"+ body: |++ The `tojson` and `fromjson` builtins dump values as JSON texts+ or parse JSON texts into values, respectively. The `tojson`+ builtin differs from `tostring` in that `tostring` returns strings+ unmodified, while `tojson` encodes strings as JSON strings.++ examples:+ - program: '[.[]|tostring]'+ input: '[1, "foo", ["foo"]]'+ output: ['["1","foo","[\"foo\"]"]']+ - program: '[.[]|tojson]'+ input: '[1, "foo", ["foo"]]'+ output: ['["1","\"foo\"","[\"foo\"]"]']+ - program: '[.[]|tojson|fromjson]'+ input: '[1, "foo", ["foo"]]'+ output: ['[1,"foo",["foo"]]']++ - title: "Format strings and escaping"+ body: |++ The `@foo` syntax is used to format and escape strings,+ which is useful for building URLs, documents in a language+ like HTML or XML, and so forth. `@foo` can be used as a+ filter on its own, the possible escapings are:++ * `@text`:++ Calls `tostring`, see that function for details.++ * `@json`:++ Serializes the input as JSON.++ * `@html`:++ Applies HTML/XML escaping, by mapping the characters+ `<>&'"` to their entity equivalents `<`, `>`,+ `&`, `'`, `"`.++ * `@uri`:++ Applies percent-encoding, by mapping all reserved URI+ characters to a `%XX` sequence.++ * `@urid`:++ The inverse of `@uri`, applies percent-decoding, by mapping+ all `%XX` sequences to their corresponding URI characters.++ * `@csv`:++ The input must be an array, and it is rendered as CSV+ with double quotes for strings, and quotes escaped by+ repetition.++ * `@tsv`:++ The input must be an array, and it is rendered as TSV+ (tab-separated values). Each input array will be printed as+ a single line. Fields are separated by a single+ tab (ascii `0x09`). Input characters line-feed (ascii `0x0a`),+ carriage-return (ascii `0x0d`), tab (ascii `0x09`) and+ backslash (ascii `0x5c`) will be output as escape sequences+ `\n`, `\r`, `\t`, `\\` respectively.++ * `@sh`:++ The input is escaped suitable for use in a command-line+ for a POSIX shell. If the input is an array, the output+ will be a series of space-separated strings.++ * `@base64`:++ The input is converted to base64 as specified by RFC 4648.++ * `@base64d`:++ The inverse of `@base64`, input is decoded as specified by RFC 4648.+ Note\: If the decoded string is not UTF-8, the results are undefined.++ This syntax can be combined with string interpolation in a+ useful way. You can follow a `@foo` token with a string+ literal. The contents of the string literal will *not* be+ escaped. However, all interpolations made inside that string+ literal will be escaped. For instance,++ @uri "https://www.google.com/search?q=\(.search)"++ will produce the following output for the input+ `{"search":"what is jq?"}`:++ "https://www.google.com/search?q=what%20is%20jq%3F"++ Note that the slashes, question mark, etc. in the URL are+ not escaped, as they were part of the string literal.++ examples:+ - program: '@html'+ input: '"This works if x < y"'+ output: ['"This works if x < y"']++ - program: '@sh "echo \(.)"'+ input: "\"O'Hara's Ale\""+ output: ["\"echo 'O'\\\\''Hara'\\\\''s Ale'\""]++ - program: '@base64'+ input: '"This is a message"'+ output: ['"VGhpcyBpcyBhIG1lc3NhZ2U="']++ - program: '@base64d'+ input: '"VGhpcyBpcyBhIG1lc3NhZ2U="'+ output: ['"This is a message"']++ - title: "Dates"+ body: |++ jq provides some basic date handling functionality, with some+ high-level and low-level builtins. In all cases these+ builtins deal exclusively with time in UTC.++ The `fromdateiso8601` builtin parses datetimes in the ISO 8601+ format to a number of seconds since the Unix epoch+ (1970-01-01T00:00:00Z). The `todateiso8601` builtin does the+ inverse.++ The `fromdate` builtin parses datetime strings. Currently+ `fromdate` only supports ISO 8601 datetime strings, but in the+ future it will attempt to parse datetime strings in more+ formats.++ The `todate` builtin is an alias for `todateiso8601`.++ The `now` builtin outputs the current time, in seconds since+ the Unix epoch.++ Low-level jq interfaces to the C-library time functions are+ also provided: `strptime`, `strftime`, `strflocaltime`,+ `mktime`, `gmtime`, and `localtime`. Refer to your host+ operating system's documentation for the format strings used+ by `strptime` and `strftime`. Note: these are not necessarily+ stable interfaces in jq, particularly as to their localization+ functionality.++ The `gmtime` builtin consumes a number of seconds since the+ Unix epoch and outputs a "broken down time" representation of+ Greenwich Mean Time as an array of numbers representing+ (in this order): the year, the month (zero-based), the day of+ the month (one-based), the hour of the day, the minute of the+ hour, the second of the minute, the day of the week, and the+ day of the year -- all one-based unless otherwise stated. The+ day of the week number may be wrong on some systems for dates+ before March 1st 1900, or after December 31 2099.++ The `localtime` builtin works like the `gmtime` builtin, but+ using the local timezone setting.++ The `mktime` builtin consumes "broken down time"+ representations of time output by `gmtime` and `strptime`.++ The `strptime(fmt)` builtin parses input strings matching the+ `fmt` argument. The output is in the "broken down time"+ representation consumed by `mktime` and output by `gmtime`.++ The `strftime(fmt)` builtin formats a time (GMT) with the+ given format. The `strflocaltime` does the same, but using+ the local timezone setting.++ The format strings for `strptime` and `strftime` are described+ in typical C library documentation. The format string for ISO+ 8601 datetime is `"%Y-%m-%dT%H:%M:%SZ"`.++ jq may not support some or all of this date functionality on+ some systems. In particular, the `%u` and `%j` specifiers for+ `strptime(fmt)` are not supported on macOS.++ examples:+ - program: 'fromdate'+ input: '"2015-03-05T23:51:47Z"'+ output: ['1425599507']++ - program: 'strptime("%Y-%m-%dT%H:%M:%SZ")'+ input: '"2015-03-05T23:51:47Z"'+ output: ['[2015,2,5,23,51,47,4,63]']++ - program: 'strptime("%Y-%m-%dT%H:%M:%SZ")|mktime'+ input: '"2015-03-05T23:51:47Z"'+ output: ['1425599507']++ - title: "SQL-Style Operators"+ body: |++ jq provides a few SQL-style operators.++ * `INDEX(stream; index_expression)`:++ This builtin produces an object whose keys are computed by+ the given index expression applied to each value from the+ given stream.++ * `JOIN($idx; stream; idx_expr; join_expr)`:++ This builtin joins the values from the given stream to the+ given index. The index's keys are computed by applying the+ given index expression to each value from the given stream.+ An array of the value in the stream and the corresponding+ value from the index is fed to the given join expression to+ produce each result.++ * `JOIN($idx; stream; idx_expr)`:++ Same as `JOIN($idx; stream; idx_expr; .)`.++ * `JOIN($idx; idx_expr)`:++ This builtin joins the input `.` to the given index, applying+ the given index expression to `.` to compute the index key.+ The join operation is as described above.++ * `IN(s)`:++ This builtin outputs `true` if `.` appears in the given+ stream, otherwise it outputs `false`.++ * `IN(source; s)`:++ This builtin outputs `true` if any value in the source stream+ appears in the second stream, otherwise it outputs `false`.++ - title: "`builtins`"+ body: |++ Returns a list of all builtin functions in the format `name/arity`.+ Since functions with the same name but different arities are considered+ separate functions, `all/0`, `all/1`, and `all/2` would all be present+ in the list.++ - title: Conditionals and Comparisons+ entries:+ - title: "`==`, `!=`"+ body: |++ The expression 'a == b' will produce 'true' if the results of evaluating+ a and b are equal (that is, if they represent equivalent JSON values) and+ 'false' otherwise. In particular, strings are never considered equal+ to numbers. In checking for the equality of JSON objects, the ordering of keys+ is irrelevant. If you're coming from JavaScript, please note that jq's `==` is like+ JavaScript's `===`, the "strict equality" operator.++ != is "not equal", and 'a != b' returns the opposite value of 'a == b'++ examples:+ - program: '. == false'+ input: 'null'+ output: ['false']++ - program: '. == {"b": {"d": (4 + 1e-20), "c": 3}, "a":1}'+ input: '{"a":1, "b": {"c": 3, "d": 4}}'+ output: ['true']++ - program: '.[] == 1'+ input: '[1, 1.0, "1", "banana"]'+ output: ['true', 'true', 'false', 'false']++ - title: if-then-else-end+ body: |++ `if A then B else C end` will act the same as `B` if `A`+ produces a value other than false or null, but act the same+ as `C` otherwise.++ `if A then B end` is the same as `if A then B else . end`.+ That is, the `else` branch is optional, and if absent is the+ same as `.`. This also applies to `elif` with absent ending `else` branch.++ Checking for false or null is a simpler notion of+ "truthiness" than is found in JavaScript or Python, but it+ means that you'll sometimes have to be more explicit about+ the condition you want. You can't test whether, e.g. a+ string is empty using `if .name then A else B end`; you'll+ need something like `if .name == "" then A else B end` instead.++ If the condition `A` produces multiple results, then `B` is evaluated+ once for each result that is not false or null, and `C` is evaluated+ once for each false or null.++ More cases can be added to an if using `elif A then B` syntax.++ examples:+ - program: |-+ if . == 0 then+ "zero"+ elif . == 1 then+ "one"+ else+ "many"+ end+ input: '2'+ output: ['"many"']++ - title: "`>`, `>=`, `<=`, `<`"+ body: |++ The comparison operators `>`, `>=`, `<=`, `<` return whether+ their left argument is greater than, greater than or equal+ to, less than or equal to or less than their right argument+ (respectively).++ The ordering is the same as that described for `sort`, above.++ examples:+ - program: '. < 5'+ input: '2'+ output: ['true']++ - title: "`and`, `or`, `not`"+ body: |++ jq supports the normal Boolean operators `and`, `or`, `not`.+ They have the same standard of truth as if expressions -+ `false` and `null` are considered "false values", and+ anything else is a "true value".++ If an operand of one of these operators produces multiple+ results, the operator itself will produce a result for each input.++ `not` is in fact a builtin function rather than an operator,+ so it is called as a filter to which things can be piped+ rather than with special syntax, as in `.foo and .bar |+ not`.++ These three only produce the values `true` and `false`, and+ so are only useful for genuine Boolean operations, rather+ than the common Perl/Python/Ruby idiom of+ "value_that_may_be_null or default". If you want to use this+ form of "or", picking between two values rather than+ evaluating a condition, see the `//` operator below.++ examples:+ - program: '42 and "a string"'+ input: 'null'+ output: ['true']+ - program: '(true, false) or false'+ input: 'null'+ output: ['true', 'false']+ - program: '(true, true) and (true, false)'+ input: 'null'+ output: ['true', 'false', 'true', 'false']+ - program: '[true, false | not]'+ input: 'null'+ output: ['[false, true]']++ - title: "Alternative operator: `//`"+ body: |++ The `//` operator produces all the values of its left-hand+ side that are neither `false` nor `null`. If the+ left-hand side produces no values other than `false` or+ `null`, then `//` produces all the values of its right-hand+ side.++ A filter of the form `a // b` produces all the results of+ `a` that are not `false` or `null`. If `a` produces no+ results, or no results other than `false` or `null`, then `a+ // b` produces the results of `b`.++ This is useful for providing defaults: `.foo // 1` will+ evaluate to `1` if there's no `.foo` element in the+ input. It's similar to how `or` is sometimes used in Python+ (jq's `or` operator is reserved for strictly Boolean+ operations).++ Note: `some_generator // defaults_here` is not the same+ as `some_generator | . // defaults_here`. The latter will+ produce default values for all non-`false`, non-`null`+ values of the left-hand side, while the former will not.+ Precedence rules can make this confusing. For example, in+ `false, 1 // 2` the left-hand side of `//` is `1`, not+ `false, 1` -- `false, 1 // 2` parses the same way as `false,+ (1 // 2)`. In `(false, null, 1) | . // 42` the left-hand+ side of `//` is `.`, which always produces just one value,+ while in `(false, null, 1) // 42` the left-hand side is a+ generator of three values, and since it produces a+ value other `false` and `null`, the default `42` is not+ produced.++ examples:+ - program: 'empty // 42'+ input: 'null'+ output: ['42']+ - program: '.foo // 42'+ input: '{"foo": 19}'+ output: ['19']+ - program: '.foo // 42'+ input: '{}'+ output: ['42']+ - program: '(false, null, 1) // 42'+ input: 'null'+ output: ['1']+ - program: '(false, null, 1) | . // 42'+ input: 'null'+ output: ['42', '42', '1']++ - title: try-catch+ body: |++ Errors can be caught by using `try EXP catch EXP`. The first+ expression is executed, and if it fails then the second is+ executed with the error message. The output of the handler,+ if any, is output as if it had been the output of the+ expression to try.++ The `try EXP` form uses `empty` as the exception handler.++ examples:+ - program: 'try .a catch ". is not an object"'+ input: 'true'+ output: ['". is not an object"']+ - program: '[.[]|try .a]'+ input: '[{}, true, {"a":1}]'+ output: ['[null, 1]']+ - program: 'try error("some exception") catch .'+ input: 'true'+ output: ['"some exception"']++ - title: Breaking out of control structures+ body: |++ A convenient use of try/catch is to break out of control+ structures like `reduce`, `foreach`, `while`, and so on.++ For example:++ # Repeat an expression until it raises "break" as an+ # error, then stop repeating without re-raising the error.+ # But if the error caught is not "break" then re-raise it.+ try repeat(exp) catch if .=="break" then empty else error++ jq has a syntax for named lexical labels to "break" or "go (back) to":++ label $out | ... break $out ...++ The `break $label_name` expression will cause the program to+ act as though the nearest (to the left) `label $label_name`+ produced `empty`.++ The relationship between the `break` and corresponding `label`+ is lexical: the label has to be "visible" from the break.++ To break out of a `reduce`, for example:++ label $out | reduce .[] as $item (null; if .==false then break $out else ... end)++ The following jq program produces a syntax error:++ break $out++ because no label `$out` is visible.++ - title: "Error Suppression / Optional Operator: `?`"+ body: |++ The `?` operator, used as `EXP?`, is shorthand for `try EXP`.++ examples:+ - program: '[.[] | .a?]'+ input: '[{}, true, {"a":1}]'+ output: ['[null, 1]']+ - program: '[.[] | tonumber?]'+ input: '["1", "invalid", "3", 4]'+ output: ['[1, 3, 4]']++ - title: Regular expressions+ body: |++ jq uses the+ [Oniguruma regular expression library](https://github.com/kkos/oniguruma/blob/master/doc/RE),+ as do PHP, TextMate, Sublime Text, etc, so the+ description here will focus on jq specifics.++ Oniguruma supports several flavors of regular expression, so it is important to know+ that jq uses the ["Perl NG" (Perl with named groups)](https://github.com/kkos/oniguruma/blob/master/doc/SYNTAX.md) flavor.++ The jq regex filters are defined so that they can be used using+ one of these patterns:++ STRING | FILTER(REGEX)+ STRING | FILTER(REGEX; FLAGS)+ STRING | FILTER([REGEX])+ STRING | FILTER([REGEX, FLAGS])++ where:++ * STRING, REGEX, and FLAGS are jq strings and subject to jq string interpolation;+ * REGEX, after string interpolation, should be a valid regular expression;+ * FILTER is one of `test`, `match`, or `capture`, as described below.++ Since REGEX must evaluate to a JSON string, some characters that are needed+ to form a regular expression must be escaped. For example, the regular expression+ `\s` signifying a whitespace character would be written as `"\\s"`.++ FLAGS is a string consisting of one of more of the supported flags:++ * `g` - Global search (find all matches, not just the first)+ * `i` - Case insensitive search+ * `m` - Multi line mode (`.` will match newlines)+ * `n` - Ignore empty matches+ * `p` - Both s and m modes are enabled+ * `s` - Single line mode (`^` -> `\A`, `$` -> `\Z`)+ * `l` - Find longest possible matches+ * `x` - Extended regex format (ignore whitespace and comments)++ To match a whitespace with the `x` flag, use `\s`, e.g.++ jq -n '"a b" | test("a\\sb"; "x")'++ Note that certain flags may also be specified within REGEX, e.g.++ jq -n '("test", "TEst", "teST", "TEST") | test("(?i)te(?-i)st")'++ evaluates to: `true`, `true`, `false`, `false`.++ entries:+ - title: "`test(val)`, `test(regex; flags)`"+ body: |++ Like `match`, but does not return match objects, only `true` or `false`+ for whether or not the regex matches the input.++ examples:+ - program: 'test("foo")'+ input: '"foo"'+ output: ['true']+ - program: '.[] | test("a b c # spaces are ignored"; "ix")'+ input: '["xabcd", "ABC"]'+ output: ['true', 'true']++ - title: "`match(val)`, `match(regex; flags)`"+ body: |++ **match** outputs an object for each match it finds. Matches have+ the following fields:++ * `offset` - offset in UTF-8 codepoints from the beginning of the input+ * `length` - length in UTF-8 codepoints of the match+ * `string` - the string that it matched+ * `captures` - an array of objects representing capturing groups.++ Capturing group objects have the following fields:++ * `offset` - offset in UTF-8 codepoints from the beginning of the input+ * `length` - length in UTF-8 codepoints of this capturing group+ * `string` - the string that was captured+ * `name` - the name of the capturing group (or `null` if it was unnamed)++ Capturing groups that did not match anything return an offset of -1++ examples:+ - program: 'match("(abc)+"; "g")'+ input: '"abc abc"'+ output:+ - '{"offset": 0, "length": 3, "string": "abc", "captures": [{"offset": 0, "length": 3, "string": "abc", "name": null}]}'+ - '{"offset": 4, "length": 3, "string": "abc", "captures": [{"offset": 4, "length": 3, "string": "abc", "name": null}]}'+ - program: 'match("foo")'+ input: '"foo bar foo"'+ output: ['{"offset": 0, "length": 3, "string": "foo", "captures": []}']+ - program: 'match(["foo", "ig"])'+ input: '"foo bar FOO"'+ output:+ - '{"offset": 0, "length": 3, "string": "foo", "captures": []}'+ - '{"offset": 8, "length": 3, "string": "FOO", "captures": []}'+ - program: 'match("foo (?<bar123>bar)? foo"; "ig")'+ input: '"foo bar foo foo foo"'+ output:+ - '{"offset": 0, "length": 11, "string": "foo bar foo", "captures": [{"offset": 4, "length": 3, "string": "bar", "name": "bar123"}]}'+ - '{"offset": 12, "length": 8, "string": "foo foo", "captures": [{"offset": -1, "length": 0, "string": null, "name": "bar123"}]}'++ - program: '[ match("."; "g")] | length'+ input: '"abc"'+ output: ['3']+++ - title: "`capture(val)`, `capture(regex; flags)`"+ body: |++ Collects the named captures in a JSON object, with the name+ of each capture as the key, and the matched string as the+ corresponding value.++ examples:+ - program: 'capture("(?<a>[a-z]+)-(?<n>[0-9]+)")'+ input: '"xyzzy-14"'+ output: ['{ "a": "xyzzy", "n": "14" }']++ - title: "`scan(regex)`, `scan(regex; flags)`"+ body: |++ Emit a stream of the non-overlapping substrings of the input+ that match the regex in accordance with the flags, if any+ have been specified. If there is no match, the stream is empty.+ To capture all the matches for each input string, use the idiom+ `[ expr ]`, e.g. `[ scan(regex) ]`. If the regex contains capturing+ groups, the filter emits a stream of arrays, each of which contains+ the captured strings.++ examples:+ - program: 'scan("c")'+ input: '"abcdefabc"'+ output: ['"c"', '"c"']+ - program: 'scan("(a+)(b+)")'+ input: '"abaabbaaabbb"'+ output: ['["a","b"]', '["aa","bb"]', '["aaa","bbb"]']++ - title: "`split(regex; flags)`"+ body: |++ Splits an input string on each regex match.++ For backwards compatibility, when called with a single argument,+ `split` splits on a string, not a regex.++ examples:+ - program: 'split(", *"; null)'+ input: '"ab,cd, ef"'+ output: ['["ab","cd","ef"]']+++ - title: "`splits(regex)`, `splits(regex; flags)`"+ body: |++ These provide the same results as their `split` counterparts,+ but as a stream instead of an array.++ examples:+ - program: 'splits(", *")'+ input: '"ab,cd, ef, gh"'+ output: ['"ab"','"cd"','"ef"','"gh"']+ - program: 'splits(",? *"; "n")'+ input: '"ab,cd ef, gh"'+ output: ['"ab"','"cd"','"ef"','"gh"']++ - title: "`sub(regex; tostring)`, `sub(regex; tostring; flags)`"+ body: |++ Emit the string obtained by replacing the first match of+ regex in the input string with `tostring`, after+ interpolation. `tostring` should be a jq string or a stream+ of such strings, each of which may contain references to+ named captures. The named captures are, in effect, presented+ as a JSON object (as constructed by `capture`) to+ `tostring`, so a reference to a captured variable named "x"+ would take the form: `"\(.x)"`.++ examples:+ - program: 'sub("[^a-z]*(?<x>[a-z]+)"; "Z\(.x)"; "g")'+ input: '"123abc456def"'+ output: ['"ZabcZdef"']++ - program: '[sub("(?<a>.)"; "\(.a|ascii_upcase)", "\(.a|ascii_downcase)")]'+ input: '"aB"'+ output: ['["AB","aB"]']++ - title: "`gsub(regex; tostring)`, `gsub(regex; tostring; flags)`"+ body: |++ `gsub` is like `sub` but all the non-overlapping occurrences of the regex are+ replaced by `tostring`, after interpolation. If the second argument is a stream+ of jq strings, then `gsub` will produce a corresponding stream of JSON strings.++ examples:+ - program: 'gsub("(?<x>.)[^a]*"; "+\(.x)-")'+ input: '"Abcabc"'+ output: ['"+A-+a-"']++ - program: '[gsub("p"; "a", "b")]'+ input: '"p"'+ output: ['["a","b"]']+++ - title: Advanced features+ body: |+ Variables are an absolute necessity in most programming languages, but+ they're relegated to an "advanced feature" in jq.++ In most languages, variables are the only means of passing around+ data. If you calculate a value, and you want to use it more than once,+ you'll need to store it in a variable. To pass a value to another part+ of the program, you'll need that part of the program to define a+ variable (as a function parameter, object member, or whatever) in+ which to place the data.++ It is also possible to define functions in jq, although this is+ is a feature whose biggest use is defining jq's standard library+ (many jq functions such as `map` and `select` are in fact written+ in jq).++ jq has reduction operators, which are very powerful but a bit+ tricky. Again, these are mostly used internally, to define some+ useful bits of jq's standard library.++ It may not be obvious at first, but jq is all about generators+ (yes, as often found in other languages). Some utilities are+ provided to help deal with generators.++ Some minimal I/O support (besides reading JSON from standard+ input, and writing JSON to standard output) is available.++ Finally, there is a module/library system.++ entries:+ - title: "Variable / Symbolic Binding Operator: `... as $identifier | ...`"+ body: |++ In jq, all filters have an input and an output, so manual+ plumbing is not necessary to pass a value from one part of a program+ to the next. Many expressions, for instance `a + b`, pass their input+ to two distinct subexpressions (here `a` and `b` are both passed the+ same input), so variables aren't usually necessary in order to use a+ value twice.++ For instance, calculating the average value of an array of numbers+ requires a few variables in most languages - at least one to hold the+ array, perhaps one for each element or for a loop counter. In jq, it's+ simply `add / length` - the `add` expression is given the array and+ produces its sum, and the `length` expression is given the array and+ produces its length.++ So, there's generally a cleaner way to solve most problems in jq than+ defining variables. Still, sometimes they do make things easier, so jq+ lets you define variables using `expression as $variable`. All+ variable names start with `$`. Here's a slightly uglier version of the+ array-averaging example:++ length as $array_length | add / $array_length++ We'll need a more complicated problem to find a situation where using+ variables actually makes our lives easier.+++ Suppose we have an array of blog posts, with "author" and "title"+ fields, and another object which is used to map author usernames to+ real names. Our input looks like:++ {"posts": [{"title": "First post", "author": "anon"},+ {"title": "A well-written article", "author": "person1"}],+ "realnames": {"anon": "Anonymous Coward",+ "person1": "Person McPherson"}}++ We want to produce the posts with the author field containing a real+ name, as in:++ {"title": "First post", "author": "Anonymous Coward"}+ {"title": "A well-written article", "author": "Person McPherson"}++ We use a variable, `$names`, to store the realnames object, so that we+ can refer to it later when looking up author usernames:++ .realnames as $names | .posts[] | {title, author: $names[.author]}++ The expression `exp as $x | ...` means: for each value of expression+ `exp`, run the rest of the pipeline with the entire original input, and+ with `$x` set to that value. Thus `as` functions as something of a+ foreach loop.++ Just as `{foo}` is a handy way of writing `{foo: .foo}`, so+ `{$foo}` is a handy way of writing `{foo: $foo}`.++ Multiple variables may be declared using a single `as` expression by+ providing a pattern that matches the structure of the input+ (this is known as "destructuring"):++ . as {realnames: $names, posts: [$first, $second]} | ...++ The variable declarations in array patterns (e.g., `. as+ [$first, $second]`) bind to the elements of the array in from+ the element at index zero on up, in order. When there is no+ value at the index for an array pattern element, `null` is+ bound to that variable.++ Variables are scoped over the rest of the expression that defines+ them, so++ .realnames as $names | (.posts[] | {title, author: $names[.author]})++ will work, but++ (.realnames as $names | .posts[]) | {title, author: $names[.author]}++ won't.++ For programming language theorists, it's more accurate to+ say that jq variables are lexically-scoped bindings. In+ particular there's no way to change the value of a binding;+ one can only setup a new binding with the same name, but which+ will not be visible where the old one was.++ examples:+ - program: '.bar as $x | .foo | . + $x'+ input: '{"foo":10, "bar":200}'+ output: ['210']+ - program: '. as $i|[(.*2|. as $i| $i), $i]'+ input: '5'+ output: ['[10,5]']+ - program: '. as [$a, $b, {c: $c}] | $a + $b + $c'+ input: '[2, 3, {"c": 4, "d": 5}]'+ output: ['9']+ - program: '.[] as [$a, $b] | {a: $a, b: $b}'+ input: '[[0], [0, 1], [2, 1, 0]]'+ output: ['{"a":0,"b":null}', '{"a":0,"b":1}', '{"a":2,"b":1}']++ - title: 'Destructuring Alternative Operator: `?//`'+ body: |++ The destructuring alternative operator provides a concise mechanism+ for destructuring an input that can take one of several forms.++ Suppose we have an API that returns a list of resources and events+ associated with them, and we want to get the user_id and timestamp of+ the first event for each resource. The API (having been clumsily+ converted from XML) will only wrap the events in an array if the resource+ has multiple events:++ {"resources": [{"id": 1, "kind": "widget", "events": {"action": "create", "user_id": 1, "ts": 13}},+ {"id": 2, "kind": "widget", "events": [{"action": "create", "user_id": 1, "ts": 14}, {"action": "destroy", "user_id": 1, "ts": 15}]}]}++ We can use the destructuring alternative operator to handle this structural change simply:++ .resources[] as {$id, $kind, events: {$user_id, $ts}} ?// {$id, $kind, events: [{$user_id, $ts}]} | {$user_id, $kind, $id, $ts}++ Or, if we aren't sure if the input is an array of values or an object:++ .[] as [$id, $kind, $user_id, $ts] ?// {$id, $kind, $user_id, $ts} | ...++ Each alternative need not define all of the same variables, but all named+ variables will be available to the subsequent expression. Variables not+ matched in the alternative that succeeded will be `null`:++ .resources[] as {$id, $kind, events: {$user_id, $ts}} ?// {$id, $kind, events: [{$first_user_id, $first_ts}]} | {$user_id, $first_user_id, $kind, $id, $ts, $first_ts}++ Additionally, if the subsequent expression returns an error, the+ alternative operator will attempt to try the next binding. Errors+ that occur during the final alternative are passed through.++ [[3]] | .[] as [$a] ?// [$b] | if $a != null then error("err: \($a)") else {$a,$b} end++ examples:+ - program: '.[] as {$a, $b, c: {$d, $e}} ?// {$a, $b, c: [{$d, $e}]} | {$a, $b, $d, $e}'+ input: '[{"a": 1, "b": 2, "c": {"d": 3, "e": 4}}, {"a": 1, "b": 2, "c": [{"d": 3, "e": 4}]}]'+ output: ['{"a":1,"b":2,"d":3,"e":4}', '{"a":1,"b":2,"d":3,"e":4}']+ - program: '.[] as {$a, $b, c: {$d}} ?// {$a, $b, c: [{$e}]} | {$a, $b, $d, $e}'+ input: '[{"a": 1, "b": 2, "c": {"d": 3, "e": 4}}, {"a": 1, "b": 2, "c": [{"d": 3, "e": 4}]}]'+ output: ['{"a":1,"b":2,"d":3,"e":null}', '{"a":1,"b":2,"d":null,"e":4}']+ - program: '.[] as [$a] ?// [$b] | if $a != null then error("err: \($a)") else {$a,$b} end'+ input: '[[3]]'+ output: ['{"a":null,"b":3}']++ - title: 'Defining Functions'+ body: |++ You can give a filter a name using "def" syntax:++ def increment: . + 1;++ From then on, `increment` is usable as a filter just like a+ builtin function (in fact, this is how many of the builtins+ are defined). A function may take arguments:++ def map(f): [.[] | f];++ Arguments are passed as _filters_ (functions with no+ arguments), _not_ as values. The same argument may be+ referenced multiple times with different inputs (here `f` is+ run for each element of the input array). Arguments to a+ function work more like callbacks than like value arguments.+ This is important to understand. Consider:++ def foo(f): f|f;+ 5|foo(.*2)++ The result will be 20 because `f` is `.*2`, and during the+ first invocation of `f` `.` will be 5, and the second time it+ will be 10 (5 * 2), so the result will be 20. Function+ arguments are filters, and filters expect an input when+ invoked.++ If you want the value-argument behaviour for defining simple+ functions, you can just use a variable:++ def addvalue(f): f as $f | map(. + $f);++ Or use the short-hand:++ def addvalue($f): ...;++ With either definition, `addvalue(.foo)` will add the current+ input's `.foo` field to each element of the array. Do note+ that calling `addvalue(.[])` will cause the `map(. + $f)` part+ to be evaluated once per value in the value of `.` at the call+ site.++ Multiple definitions using the same function name are allowed.+ Each re-definition replaces the previous one for the same+ number of function arguments, but only for references from+ functions (or main program) subsequent to the re-definition.+ See also the section below on scoping.++ examples:+ - program: 'def addvalue(f): . + [f]; map(addvalue(.[0]))'+ input: '[[1,2],[10,20]]'+ output: ['[[1,2,1], [10,20,10]]']+ - program: 'def addvalue(f): f as $x | map(. + $x); addvalue(.[0])'+ input: '[[1,2],[10,20]]'+ output: ['[[1,2,1,2], [10,20,1,2]]']++ - title: 'Scoping'+ body: |++ There are two types of symbols in jq: value bindings (a.k.a.,+ "variables"), and functions. Both are scoped lexically,+ with expressions being able to refer only to symbols that+ have been defined "to the left" of them. The only exception+ to this rule is that functions can refer to themselves so as+ to be able to create recursive functions.++ For example, in the following expression there is a binding+ which is visible "to the right" of it, `... | .*3 as+ $times_three | [. + $times_three] | ...`, but not "to the+ left". Consider this expression now, `... | (.*3 as+ $times_three | [. + $times_three]) | ...`: here the binding+ `$times_three` is _not_ visible past the closing parenthesis.++ - title: "`isempty(exp)`"+ body: |++ Returns true if `exp` produces no outputs, false otherwise.++ examples:+ - program: 'isempty(empty)'+ input: 'null'+ output: ['true']++ - program: 'isempty(.[])'+ input: '[]'+ output: ['true']++ - program: 'isempty(.[])'+ input: '[1,2,3]'+ output: ['false']++ - title: "`limit(n; expr)`"+ body: |++ The `limit` function extracts up to `n` outputs from `expr`.++ examples:+ - program: '[limit(3; .[])]'+ input: '[0,1,2,3,4,5,6,7,8,9]'+ output: ['[0,1,2]']++ - title: "`skip(n; expr)`"+ body: |++ The `skip` function skips the first `n` outputs from `expr`.++ examples:+ - program: '[skip(3; .[])]'+ input: '[0,1,2,3,4,5,6,7,8,9]'+ output: ['[3,4,5,6,7,8,9]']++ - title: "`first(expr)`, `last(expr)`, `nth(n; expr)`"+ body: |++ The `first(expr)` and `last(expr)` functions extract the first+ and last values from `expr`, respectively.++ The `nth(n; expr)` function extracts the nth value output by `expr`.+ Note that `nth(n; expr)` doesn't support negative values of `n`.++ examples:+ - program: '[first(range(.)), last(range(.)), nth(5; range(.))]'+ input: '10'+ output: ['[0,9,5]']+ - program: '[first(empty), last(empty), nth(5; empty)]'+ input: 'null'+ output: ['[]']++ - title: "`first`, `last`, `nth(n)`"+ body: |++ The `first` and `last` functions extract the first+ and last values from any array at `.`.++ The `nth(n)` function extracts the nth value of any array at `.`.++ examples:+ - program: '[range(.)]|[first, last, nth(5)]'+ input: '10'+ output: ['[0,9,5]']++ - title: "`reduce`"+ body: |++ The `reduce` syntax allows you to combine all of the results of+ an expression by accumulating them into a single answer.+ The form is `reduce EXP as $var (INIT; UPDATE)`.+ As an example, we'll pass `[1,2,3]` to this expression:++ reduce .[] as $item (0; . + $item)++ For each result that `.[]` produces, `. + $item` is run to+ accumulate a running total, starting from 0 as the input value.+ In this example, `.[]` produces the results `1`, `2`, and `3`,+ so the effect is similar to running something like this:++ 0 | 1 as $item | . + $item |+ 2 as $item | . + $item |+ 3 as $item | . + $item++ examples:+ - program: 'reduce .[] as $item (0; . + $item)'+ input: '[1,2,3,4,5]'+ output: ['15']++ - program: 'reduce .[] as [$i,$j] (0; . + $i * $j)'+ input: '[[1,2],[3,4],[5,6]]'+ output: ['44']++ - program: 'reduce .[] as {$x,$y} (null; .x += $x | .y += [$y])'+ input: '[{"x":"a","y":1},{"x":"b","y":2},{"x":"c","y":3}]'+ output: ['{"x":"abc","y":[1,2,3]}']++ - title: "`foreach`"+ body: |++ The `foreach` syntax is similar to `reduce`, but intended to+ allow the construction of `limit` and reducers that produce+ intermediate results.++ The form is `foreach EXP as $var (INIT; UPDATE; EXTRACT)`.+ As an example, we'll pass `[1,2,3]` to this expression:++ foreach .[] as $item (0; . + $item; [$item, . * 2])++ Like the `reduce` syntax, `. + $item` is run for each result+ that `.[]` produces, but `[$item, . * 2]` is run for each+ intermediate values. In this example, since the intermediate+ values are `1`, `3`, and `6`, the `foreach` expression produces+ `[1,2]`, `[2,6]`, and `[3,12]`. So the effect is similar+ to running something like this:++ 0 | 1 as $item | . + $item | [$item, . * 2],+ 2 as $item | . + $item | [$item, . * 2],+ 3 as $item | . + $item | [$item, . * 2]++ When `EXTRACT` is omitted, the identity filter is used.+ That is, it outputs the intermediate values as they are.++ examples:+ - program: 'foreach .[] as $item (0; . + $item)'+ input: '[1,2,3,4,5]'+ output: ['1','3','6','10','15']++ - program: 'foreach .[] as $item (0; . + $item; [$item, . * 2])'+ input: '[1,2,3,4,5]'+ output: ['[1,2]','[2,6]','[3,12]','[4,20]','[5,30]']++ - program: 'foreach .[] as $item (0; . + 1; {index: ., $item})'+ input: '["foo", "bar", "baz"]'+ output:+ - '{"index":1,"item":"foo"}'+ - '{"index":2,"item":"bar"}'+ - '{"index":3,"item":"baz"}'++ - title: Recursion+ body: |++ As described above, `recurse` uses recursion, and any jq+ function can be recursive. The `while` builtin is also+ implemented in terms of recursion.++ Tail calls are optimized whenever the expression to the left of+ the recursive call outputs its last value. In practice this+ means that the expression to the left of the recursive call+ should not produce more than one output for each input.++ For example:++ def recurse(f): def r: ., (f | select(. != null) | r); r;++ def while(cond; update):+ def _while:+ if cond then ., (update | _while) else empty end;+ _while;++ def repeat(exp):+ def _repeat:+ exp, _repeat;+ _repeat;++ - title: Generators and iterators+ body: |++ Some jq operators and functions are actually generators in+ that they can produce zero, one, or more values for each+ input, just as one might expect in other programming+ languages that have generators. For example, `.[]`+ generates all the values in its input (which must be an+ array or an object), `range(0; 10)` generates the integers+ between 0 and 10, and so on.++ Even the comma operator is a generator, generating first+ the values generated by the expression to the left of the+ comma, then the values generated by the expression on the+ right of the comma.++ The `empty` builtin is the generator that produces zero+ outputs. The `empty` builtin backtracks to the preceding+ generator expression.++ All jq functions can be generators just by using builtin+ generators. It is also possible to construct new generators+ using only recursion and the comma operator. If+ recursive calls are "in tail position" then the+ generator will be efficient. In the example below the+ recursive call by `_range` to itself is in tail position.+ The example shows off three advanced topics: tail recursion,+ generator construction, and sub-functions.++ examples:+ - program: 'def range(init; upto; by):+ def _range:+ if (by > 0 and . < upto) or (by < 0 and . > upto)+ then ., ((.+by)|_range)+ else empty end;+ if init == upto then empty elif by == 0 then init else init|_range end;+ range(0; 10; 3)'+ input: 'null'+ output: ['0', '3', '6', '9']+ - program: 'def while(cond; update):+ def _while:+ if cond then ., (update | _while) else empty end;+ _while;+ [while(.<100; .*2)]'+ input: '1'+ output: ['[1,2,4,8,16,32,64]']++ - title: 'Math'+ body: |++ jq currently only has IEEE754 double-precision (64-bit) floating+ point number support.++ Besides simple arithmetic operators such as `+`, jq also has most+ standard math functions from the C math library. C math functions+ that take a single input argument (e.g., `sin()`) are available as+ zero-argument jq functions. C math functions that take two input+ arguments (e.g., `pow()`) are available as two-argument jq+ functions that ignore `.`. C math functions that take three input+ arguments are available as three-argument jq functions that ignore+ `.`.++ Availability of standard math functions depends on the+ availability of the corresponding math functions in your operating+ system and C math library. Unavailable math functions will be+ defined but will raise an error.++ One-input C math functions: `acos` `acosh` `asin` `asinh` `atan`+ `atanh` `cbrt` `ceil` `cos` `cosh` `erf` `erfc` `exp` `exp10`+ `exp2` `expm1` `fabs` `floor` `gamma` `j0` `j1` `lgamma` `log`+ `log10` `log1p` `log2` `logb` `nearbyint` `rint` `round`+ `significand` `sin` `sinh` `sqrt` `tan` `tanh` `tgamma` `trunc`+ `y0` `y1`.++ Two-input C math functions: `atan2` `copysign` `drem` `fdim`+ `fmax` `fmin` `fmod` `frexp` `hypot` `jn` `ldexp` `modf`+ `nextafter` `nexttoward` `pow` `remainder` `scalb` `scalbln` `yn`.++ Three-input C math functions: `fma`.++ See your system's manual for more information on each of these.++ - title: 'I/O'+ body: |++ At this time jq has minimal support for I/O, mostly in the+ form of control over when inputs are read. Two builtins functions+ are provided for this, `input` and `inputs`, that read from the+ same sources (e.g., `stdin`, files named on the command-line) as+ jq itself. These two builtins, and jq's own reading actions, can+ be interleaved with each other. They are commonly used in combination+ with the null input option `-n` to prevent one input from being read+ implicitly.++ Two builtins provide minimal output capabilities, `debug`, and+ `stderr`. (Recall that a jq program's output values are always+ output as JSON texts on `stdout`.) The `debug` builtin can have+ application-specific behavior, such as for executables that use+ the libjq C API but aren't the jq executable itself. The `stderr`+ builtin outputs its input in raw mode to stder with no additional+ decoration, not even a newline.++ Most jq builtins are referentially transparent, and yield constant+ and repeatable value streams when applied to constant inputs.+ This is not true of I/O builtins.++ entries:+ - title: "`input`"+ body: |++ Outputs one new input.++ Note that when using `input` it is generally be necessary to+ invoke jq with the `-n` command-line option, otherwise+ the first entity will be lost.++ echo 1 2 3 4 | jq '[., input]' # [1,2] [3,4]++ - title: "`inputs`"+ body: |++ Outputs all remaining inputs, one by one.++ This is primarily useful for reductions over a program's+ inputs. Note that when using `inputs` it is generally necessary+ to invoke jq with the `-n` command-line option, otherwise+ the first entity will be lost.++ echo 1 2 3 | jq -n 'reduce inputs as $i (0; . + $i)' # 6++ - title: "`debug`, `debug(msgs)`"+ body: |++ These two filters are like `.` but have as a side-effect the+ production of one or more messages on stderr.++ The message produced by the `debug` filter has the form++ ["DEBUG:",<input-value>]++ where `<input-value>` is a compact rendition of the input+ value. This format may change in the future.++ The `debug(msgs)` filter is defined as `(msgs | debug | empty), .`+ thus allowing great flexibility in the content of the message,+ while also allowing multi-line debugging statements to be created.++ For example, the expression:++ 1 as $x | 2 | debug("Entering function foo with $x == \($x)", .) | (.+1)++ would produce the value 3 but with the following two lines+ being written to stderr:++ ["DEBUG:","Entering function foo with $x == 1"]+ ["DEBUG:",2]++ - title: "`stderr`"+ body: |++ Prints its input in raw and compact mode to stderr with no+ additional decoration, not even a newline.++ - title: "`input_filename`"+ body: |++ Returns the name of the file whose input is currently being+ filtered. Note that this will not work well unless jq is+ running in a UTF-8 locale.++ - title: "`input_line_number`"+ body: |++ Returns the line number of the input currently being filtered.++ - title: 'Streaming'+ body: |++ With the `--stream` option jq can parse input texts in a streaming+ fashion, allowing jq programs to start processing large JSON texts+ immediately rather than after the parse completes. If you have a+ single JSON text that is 1GB in size, streaming it will allow you+ to process it much more quickly.++ However, streaming isn't easy to deal with as the jq program will+ have `[<path>, <leaf-value>]` (and a few other forms) as inputs.++ Several builtins are provided to make handling streams easier.++ The examples below use the streamed form of `["a",["b"]]`, which is+ `[[0],"a"],[[1,0],"b"],[[1,0]],[[1]]`.++ Streaming forms include `[<path>, <leaf-value>]` (to indicate any+ scalar value, empty array, or empty object), and `[<path>]` (to+ indicate the end of an array or object). Future versions of jq+ run with `--stream` and `--seq` may output additional forms such+ as `["error message"]` when an input text fails to parse.++ entries:+ - title: "`truncate_stream(stream_expression)`"+ body: |++ Consumes a number as input and truncates the corresponding+ number of path elements from the left of the outputs of the+ given streaming expression.++ examples:+ - program: 'truncate_stream([[0],"a"],[[1,0],"b"],[[1,0]],[[1]])'+ input: '1'+ output: ['[[0],"b"]', '[[0]]']++ - title: "`fromstream(stream_expression)`"+ body: |++ Outputs values corresponding to the stream expression's+ outputs.++ examples:+ - program: 'fromstream(1|truncate_stream([[0],"a"],[[1,0],"b"],[[1,0]],[[1]]))'+ input: 'null'+ output: ['["b"]']++ - title: "`tostream`"+ body: |++ The `tostream` builtin outputs the streamed form of its input.++ examples:+ - program: '. as $dot|fromstream($dot|tostream)|.==$dot'+ input: '[0,[1,{"a":1},{"b":2}]]'+ output: ['true']++ - title: Assignment+ body: |+ Assignment works a little differently in jq than in most+ programming languages. jq doesn't distinguish between references+ to and copies of something - two objects or arrays are either+ equal or not equal, without any further notion of being "the+ same object" or "not the same object".++ If an object has two fields which are arrays, `.foo` and `.bar`,+ and you append something to `.foo`, then `.bar` will not get+ bigger, even if you've previously set `.bar = .foo`. If you're+ used to programming in languages like Python, Java, Ruby,+ JavaScript, etc. then you can think of it as though jq does a full+ deep copy of every object before it does the assignment (for+ performance it doesn't actually do that, but that's the general+ idea).++ This means that it's impossible to build circular values in jq+ (such as an array whose first element is itself). This is quite+ intentional, and ensures that anything a jq program can produce+ can be represented in JSON.++ All the assignment operators in jq have path expressions on the+ left-hand side (LHS). The right-hand side (RHS) provides values+ to set to the paths named by the LHS path expressions.++ Values in jq are always immutable. Internally, assignment works+ by using a reduction to compute new, replacement values for `.` that+ have had all the desired assignments applied to `.`, then+ outputting the modified value. This might be made clear by this+ example: `{a:{b:{c:1}}} | (.a.b|=3), .`. This will output+ `{"a":{"b":3}}` and `{"a":{"b":{"c":1}}}` because the last+ sub-expression, `.`, sees the original value, not the modified+ value.++ Most users will want to use modification assignment operators,+ such as `|=` or `+=`, rather than `=`.++ Note that the LHS of assignment operators refers to a value in+ `.`. Thus `$var.foo = 1` won't work as expected (`$var.foo` is+ not a valid or useful path expression in `.`); use `$var | .foo =+ 1` instead.++ Note too that `.a,.b=0` does not set `.a` and `.b`, but+ `(.a,.b)=0` sets both.++ entries:+ - title: "Update-assignment: `|=`"+ body: |+ This is the "update" operator `|=`. It takes a filter on the+ right-hand side and works out the new value for the property+ of `.` being assigned to by running the old value through this+ expression. For instance, `(.foo, .bar) |= .+1` will build an+ object with the `foo` field set to the input's `foo` plus 1,+ and the `bar` field set to the input's `bar` plus 1.++ The left-hand side can be any general path expression; see `path()`.++ Note that the left-hand side of `|=` refers to a value in `.`.+ Thus `$var.foo |= . + 1` won't work as expected (`$var.foo` is+ not a valid or useful path expression in `.`); use `$var |+ .foo |= . + 1` instead.++ If the right-hand side outputs no values (i.e., `empty`), then+ the left-hand side path will be deleted, as with `del(path)`.++ If the right-hand side outputs multiple values, only the first+ one will be used (COMPATIBILITY NOTE: in jq 1.5 and earlier+ releases, it used to be that only the last one was used).++ examples:+ - program: '(..|select(type=="boolean")) |= if . then 1 else 0 end'+ input: '[true,false,[5,true,[true,[false]],false]]'+ output: ['[1,0,[5,1,[1,[0]],0]]']++ - title: "Arithmetic update-assignment: `+=`, `-=`, `*=`, `/=`, `%=`, `//=`"+ body: |++ jq has a few operators of the form `a op= b`, which are all+ equivalent to `a |= . op b`. So, `+= 1` can be used to+ increment values, being the same as `|= . + 1`.++ examples:+ - program: .foo += 1+ input: '{"foo": 42}'+ output: ['{"foo": 43}']++ - title: "Plain assignment: `=`"+ body: |++ This is the plain assignment operator. Unlike the others, the+ input to the right-hand side (RHS) is the same as the input to+ the left-hand side (LHS) rather than the value at the LHS+ path, and all values output by the RHS will be used (as shown+ below).++ If the RHS of `=` produces multiple values, then for each such+ value jq will set the paths on the left-hand side to the value+ and then it will output the modified `.`. For example,+ `(.a,.b) = range(2)` outputs `{"a":0,"b":0}`, then+ `{"a":1,"b":1}`. The "update" assignment forms (see above) do+ not do this.++ This example should show the difference between `=` and `|=`:++ Provide input `{"a": {"b": 10}, "b": 20}` to the programs++ .a = .b++ and++ .a |= .b++ The former will set the `a` field of the input to the `b`+ field of the input, and produce the output `{"a": 20, "b": 20}`.+ The latter will set the `a` field of the input to the `a`+ field's `b` field, producing `{"a": 10, "b": 20}`.++ examples:+ - program: .a = .b+ input: '{"a": {"b": 10}, "b": 20}'+ output: ['{"a":20,"b":20}']++ - program: .a |= .b+ input: '{"a": {"b": 10}, "b": 20}'+ output: ['{"a":10,"b":20}']++ - program: (.a, .b) = range(3)+ input: 'null'+ output:+ - '{"a":0,"b":0}'+ - '{"a":1,"b":1}'+ - '{"a":2,"b":2}'++ - program: (.a, .b) |= range(3)+ input: 'null'+ output: ['{"a":0,"b":0}']++ - title: Complex assignments+ body: |+ Lots more things are allowed on the left-hand side of a jq assignment+ than in most languages. We've already seen simple field accesses on+ the left hand side, and it's no surprise that array accesses work just+ as well:++ .posts[0].title = "JQ Manual"++ What may come as a surprise is that the expression on the left may+ produce multiple results, referring to different points in the input+ document:++ .posts[].comments |= . + ["this is great"]++ That example appends the string "this is great" to the "comments"+ array of each post in the input (where the input is an object with a+ field "posts" which is an array of posts).++ When jq encounters an assignment like 'a = b', it records the "path"+ taken to select a part of the input document while executing a. This+ path is then used to find which part of the input to change while+ executing the assignment. Any filter may be used on the+ left-hand side of an equals - whichever paths it selects from the+ input will be where the assignment is performed.++ This is a very powerful operation. Suppose we wanted to add a comment+ to blog posts, using the same "blog" input above. This time, we only+ want to comment on the posts written by "stedolan". We can find those+ posts using the "select" function described earlier:++ .posts[] | select(.author == "stedolan")++ The paths provided by this operation point to each of the posts that+ "stedolan" wrote, and we can comment on each of them in the same way+ that we did before:++ (.posts[] | select(.author == "stedolan") | .comments) |=+ . + ["terrible."]++ - title: Comments++ body: |++ You can write comments in your jq filters using `#`.++ A `#` character (not part of a string) starts a comment.+ All characters from `#` to the end of the line are ignored.++ If the end of the line is preceded by an odd number of backslash+ characters, the following line is also considered part of the+ comment and is ignored.++ For example, the following code outputs `[1,3,4,7]`++ [+ 1,+ # foo \+ 2,+ # bar \\+ 3,+ 4, # baz \\\+ 5, \+ 6,+ 7+ # comment \+ comment \+ comment+ ]++ Backslash continuing the comment on the next line can be useful+ when writing the "shebang" for a jq script:++ #!/bin/sh --+ # total - Output the sum of the given arguments (or stdin)+ # usage: total [numbers...]+ # \+ exec jq --args -MRnf -- "$0" "$@"++ $ARGS.positional |+ reduce (+ if . == []+ then inputs+ else .[]+ end |+ . as $dot |+ try tonumber catch false |+ if not or isnan then+ @json "total: Invalid number \($dot).\n" | halt_error(1)+ end+ ) as $n (0; . + $n)++ The `exec` line is considered a comment by jq, so it is ignored.+ But it is not ignored by `sh`, since in `sh` a backslash at the+ end of the line does not continue the comment.+ With this trick, when the script is invoked as `total 1 2`,+ `/bin/sh -- /path/to/total 1 2` will be run, and `sh` will then+ run `exec jq --args -MRnf -- /path/to/total 1 2` replacing itself+ with a `jq` interpreter invoked with the specified options (`-M`,+ `-R`, `-n`, `--args`), that evaluates the current file (`$0`),+ with the arguments (`$@`) that were passed to `sh`.++ - title: Modules+ body: |++ jq has a library/module system. Modules are files whose names end+ in `.jq`.++ Modules imported by a program are searched for in a default search+ path (see below). The `import` and `include` directives allow the+ importer to alter this path.++ Paths in the search path are subject to various substitutions.++ For paths starting with `~/`, the user's home directory is+ substituted for `~`.++ For paths starting with `$ORIGIN/`, the directory where the jq+ executable is located is substituted for `$ORIGIN`.++ For paths starting with `./` or paths that are `.`, the path of+ the including file is substituted for `.`. For top-level programs+ given on the command-line, the current directory is used.++ Import directives can optionally specify a search path to which+ the default is appended.++ The default search path is the search path given to the `-L`+ command-line option, else `["~/.jq", "$ORIGIN/../lib/jq",+ "$ORIGIN/../lib"]`.++ Null and empty string path elements terminate search path+ processing.++ A dependency with relative path `foo/bar` would be searched for in+ `foo/bar.jq` and `foo/bar/bar.jq` in the given search path. This+ is intended to allow modules to be placed in a directory along+ with, for example, version control files, README files, and so on,+ but also to allow for single-file modules.++ Consecutive components with the same name are not allowed to avoid+ ambiguities (e.g., `foo/foo`).++ For example, with `-L$HOME/.jq` a module `foo` can be found in+ `$HOME/.jq/foo.jq` and `$HOME/.jq/foo/foo.jq`.++ If `.jq` exists in the user's home directory, and is a file (not a+ directory), it is automatically sourced into the main program.++ entries:+ - title: "`import RelativePathString as NAME [<metadata>];`"+ body: |++ Imports a module found at the given path relative to a+ directory in a search path. A `.jq` suffix will be added to+ the relative path string. The module's symbols are prefixed+ with `NAME::`.++ The optional metadata must be a constant jq expression. It+ should be an object with keys like `homepage` and so on. At+ this time jq only uses the `search` key/value of the metadata.+ The metadata is also made available to users via the+ `modulemeta` builtin.++ The `search` key in the metadata, if present, should have a+ string or array value (array of strings); this is the search+ path to be prefixed to the top-level search path.++ - title: "`include RelativePathString [<metadata>];`"+ body: |++ Imports a module found at the given path relative to a+ directory in a search path as if it were included in place. A+ `.jq` suffix will be added to the relative path string. The+ module's symbols are imported into the caller's namespace as+ if the module's content had been included directly.++ The optional metadata must be a constant jq expression. It+ should be an object with keys like `homepage` and so on. At+ this time jq only uses the `search` key/value of the metadata.+ The metadata is also made available to users via the+ `modulemeta` builtin.++ - title: "`import RelativePathString as $NAME [<metadata>];`"+ body: |++ Imports a JSON file found at the given path relative to a+ directory in a search path. A `.json` suffix will be added to+ the relative path string. The file's data will be available+ as `$NAME::NAME`.++ The optional metadata must be a constant jq expression. It+ should be an object with keys like `homepage` and so on. At+ this time jq only uses the `search` key/value of the metadata.+ The metadata is also made available to users via the+ `modulemeta` builtin.++ The `search` key in the metadata, if present, should have a+ string or array value (array of strings); this is the search+ path to be prefixed to the top-level search path.++ - title: "`module <metadata>;`"+ body: |++ This directive is entirely optional. It's not required for+ proper operation. It serves only the purpose of providing+ metadata that can be read with the `modulemeta` builtin.++ The metadata must be a constant jq expression. It should be+ an object with keys like `homepage`. At this time jq doesn't+ use this metadata, but it is made available to users via the+ `modulemeta` builtin.++ - title: "`modulemeta`"+ body: |++ Takes a module name as input and outputs the module's metadata+ as an object, with the module's imports (including metadata)+ as an array value for the `deps` key and the module's defined+ functions as an array value for the `defs` key.++ Programs can use this to query a module's metadata, which they+ could then use to, for example, search for, download, and+ install missing dependencies.++ - title: Colors+ body: |++ To configure alternative colors just set the `JQ_COLORS`+ environment variable to colon-delimited list of partial terminal+ escape sequences like `"1;31"`, in this order:++ - color for `null`+ - color for `false`+ - color for `true`+ - color for numbers+ - color for strings+ - color for arrays+ - color for objects+ - color for object keys++ The default color scheme is the same as setting+ `JQ_COLORS="0;90:0;39:0;39:0;39:0;32:1;39:1;39:1;34"`.++ This is not a manual for VT100/ANSI escapes. However, each of+ these color specifications should consist of two numbers separated+ by a semi-colon, where the first number is one of these:++ - 1 (bright)+ - 2 (dim)+ - 4 (underscore)+ - 5 (blink)+ - 7 (reverse)+ - 8 (hidden)++ and the second is one of these:++ - 30 (black)+ - 31 (red)+ - 32 (green)+ - 33 (yellow)+ - 34 (blue)+ - 35 (magenta)+ - 36 (cyan)+ - 37 (white)
@@ -14,15 +14,15 @@ <h2 class="px-1" style="width:16em">{{ blurb }}</h2> <div class="btn-group d-print-none" role="group"> <button type="button" class="btn btn-primary dropdown-toggle text-nowrap" data-bs-toggle="dropdown" aria-expanded="false">- Download jq 1.7.1+ Download jq 1.8.0 <span class="caret"></span> </button> <ul class="dropdown-menu">- <li><a class="dropdown-item" href="https://github.com/jqlang/jq/releases/download/jq-1.7.1/jq-linux-amd64" aria-label="Link to download executable: Linux (AMD64)"><span class="bi bi-download me-2" aria-hidden="true"></span>Linux (AMD64)</a></li>- <li><a class="dropdown-item" href="https://github.com/jqlang/jq/releases/download/jq-1.7.1/jq-linux-arm64" aria-label="Link to download executable: Linux (ARM64)"><span class="bi bi-download me-2" aria-hidden="true"></span>Linux (ARM64)</a></li>- <li><a class="dropdown-item" href="https://github.com/jqlang/jq/releases/download/jq-1.7.1/jq-macos-amd64" aria-label="Link to download executable: macOS (AMD64)"><span class="bi bi-download me-2" aria-hidden="true"></span>macOS (AMD64)</a></li>- <li><a class="dropdown-item" href="https://github.com/jqlang/jq/releases/download/jq-1.7.1/jq-macos-arm64" aria-label="Link to download executable: macOS (ARM64)"><span class="bi bi-download me-2" aria-hidden="true"></span>macOS (ARM64)</a></li>- <li><a class="dropdown-item" href="https://github.com/jqlang/jq/releases/download/jq-1.7.1/jq-windows-amd64.exe" aria-label="Link to download executable: Windows (AMD64)"><span class="bi bi-download me-2" aria-hidden="true"></span>Windows (AMD64)</a></li>+ <li><a class="dropdown-item" href="https://github.com/jqlang/jq/releases/download/jq-1.8.0/jq-linux-amd64" aria-label="Link to download executable: Linux (AMD64)"><span class="bi bi-download me-2" aria-hidden="true"></span>Linux (AMD64)</a></li>+ <li><a class="dropdown-item" href="https://github.com/jqlang/jq/releases/download/jq-1.8.0/jq-linux-arm64" aria-label="Link to download executable: Linux (ARM64)"><span class="bi bi-download me-2" aria-hidden="true"></span>Linux (ARM64)</a></li>+ <li><a class="dropdown-item" href="https://github.com/jqlang/jq/releases/download/jq-1.8.0/jq-macos-arm64" aria-label="Link to download executable: macOS (Apple Silicon)"><span class="bi bi-download me-2" aria-hidden="true"></span>macOS (Apple Silicon)</a></li>+ <li><a class="dropdown-item" href="https://github.com/jqlang/jq/releases/download/jq-1.8.0/jq-macos-amd64" aria-label="Link to download executable: macOS (Intel Mac)"><span class="bi bi-download me-2" aria-hidden="true"></span>macOS (Intel Mac)</a></li>+ <li><a class="dropdown-item" href="https://github.com/jqlang/jq/releases/download/jq-1.8.0/jq-windows-amd64.exe" aria-label="Link to download executable: Windows (AMD64)"><span class="bi bi-download me-2" aria-hidden="true"></span>Windows (AMD64)</a></li> <li><a class="dropdown-item" href="/download/">Other platforms, older versions, and source</a></li> </ul> <a class="btn btn-primary text-nowrap" href="https://play.jqlang.org" rel="noopener">
@@ -36,6 +36,7 @@ <p> <em> For other versions, see+ <a href="/manual/v1.8/">1.8</a>, <a href="/manual/v1.7/">1.7</a>, <a href="/manual/v1.6/">1.6</a>, <a href="/manual/v1.5/">1.5</a>,