||||||~ # versionversion|| ||~ ||~ [#jq jq]||~ [#jsonnet jsonnet]|| ||# version-used[#version-used-note version used] _ @< >@||##gray|//1.5//##||##gray|//0.20//##|| ||# show-version[#show-version-note show version] _ @< >@||$ jq @@–@@version||$ jsoneet @@–@@version|| ||||||~ # grammar-invocationgrammar and execution|| ||~ ||~ [#jq jq]||~ [#jsonnet jsonnet]|| ||# interpreter[#interpreter-note interpreter]||$ cat > hello.jq _ “Hello, World!” _ _ ##gray|# -n: use single “null” as input _

-r: write string content instead of quoted string literal## _

$ jq -nr -f hello.jq _ Hello, World!||##gray|# -e: interpret 1st argument as expression## _ ##gray|# -S: write string content instead of quoted string literal## _ $ jsonnet -eS ‘“Hello, World!”’ _ Hellow, World!|| ||# cmd-line-program[#cmd-line-program-note command line program]||$ echo ‘1 2 3’ | jq ‘. * .’ _ _ ##gray|# no stdin:## _ $ jq -n ‘1 + 1’ || || ||# stmt-separator[#stmt-separator-note statement separator]||##gray|A program consists of filter expressions separated by commas and pipes: , | _ _ A filter expressions acts on its input and produces output. _ _ The pipe separator makes the output of the left expression the input of the right expression. _ _ The comma separator, which concatenates the output of two filters, has higher precedence than the pipe separator. _ _ A function definition, include statement, or import statement is terminated by a semicolon: ;##||##gray|A program consists of zero or more local expressions followed by semicolons, with a final non-local expression##|| ||# block-delimiters[#block-delimiters-note block delimiters] _ @< >@||##gray|# Use parens to change precedence:## _ $ jq -n ‘2, (3 | . * .)’ _ $ jq -n ‘2, 3 | . * .’|| || ||# eol-comment[#eol-comment-note end of line comment] _ @< >@||##gray|# comment##||##gray|# python-style comment## _ _ ##gray|@@//@@ C++-style comment##|| ||||~ # var-exprvariables and expressions|| ||~ ||~ jq|| ||# assignment[#assignment-note assignment]||$ echo ‘[1,2,3]’ | jq ‘length as $x | map(. * $x)’ _ _ ##gray|"length as $x” assigns the value 3 to $x. _ _ The following filter receives the same input the assignment filter got.##|| ||# compound-assignment[#compound-assignment-note compound assignment]||@@|= += -= *= /= %= //=@@ _ _ ##gray|Compound operators are used with arrays and dictionaries. A copy of the array or dictionary is returned, with fields specified on the LHS replaced by new values. If the compound assignment expression is “LHS OP= RHS”, then the new value is “LHS OP RHS”.## _ _ ##gray|# {"t”: 2, “f”: 0}:## _ $ echo ‘{"t”: 1, “f”: 0}’ | jq ‘.t += 1’ _ _ ##gray|More than one field can be updated. _ _

{"t”: 2, “f”: 1}:## _

$ echo ‘{"t”: 1, “f”: 0}’ | jq ‘.[] += 1’|| ||# null[#null-note null] _ @< >@||null|| ||# null-test[#null-test-note null test] _ @< >@||$ echo ‘{"name”: “Ed”}’ | jq ‘.age == null’|| ||# coalesce[#coalesce-note coalesce]||##gray|# also replaces false:## _ $ echo ‘{}’ | jq ‘.age // 0’|| ||# conditional-expr[#conditional-expr-note conditional expression] _ @< >@||$ echo ‘-3’ | jq ‘if . < 0 then -. else . end’|| ||||~ # arith-logicarithmetic and logic|| ||~ ||~ jq|| ||# true-false[#true-false-note true and false] _ @< >@||true false|| ||# falsehoods[#falsehoods-note falsehoods] _ @< >@||null false|| ||# logical-op[#logical-op-note logical operators] _ @< >@||and or not|| ||# relational-op[#relational-op-note relational operators] _ @< >@||@@==@@ != < > <= >=|| ||# min-max[#min-max-note min and max] _ @< >@||$ echo ‘[1,2,3]’ | jq ‘min’ _ $ echo ‘[1,2,3]’ | jq ‘max’|| ||# arith-op[#arith-op-note arithmetic operators] _ @< >@||+ - * / %|| ||# int-division[#int-division-note integer division]||##gray|# floor is new in 1.4:## _ $ jq -n ‘-13 / 5 | floor’|| ||# division-by-zero[#division-by-zero-note division by zero] _ @< >@||##gray|//error//##|| ||# sqrt[#sqrt-note sqrt]||##gray|# new in 1.4:## _ $ jq -n ‘2 | sqrt’|| ||# sqrt-negative-one[#sqrt-negative-one-note sqrt -1]||##gray|# null:## _ $ jq -n ‘-1 | sqrt’|| ||# transcendental-func[#transcendental-func-note transcendental functions]||##gray|# new in 1.5:## _ exp log _ sin cos tan _ asin acos atan|| ||# float-trunc[#float-trunc-note float truncation]||##gray|# floor is new in 1.4:## _ $ jq ‘1.1 | floor’|| ||||~ # stringsstrings|| ||~ ||~ jq|| ||# str-literal[#str-literal-note literal] _ @< >@||"lorem ipsum”|| ||# newline-in-literal[#new-line-in-literal-note newline in literal] _ @< >@||##gray|//not allowed; use// \n //escape sequence//##|| ||# str-esc[#str-esc-note string escapes] _ @< >@||\ " \/ \b \f \n \r \r \t \u##gray|//hhhh//##|| ||# var-interpolation[#var-interpolation-note variable interpolation] _ @< >@||$ echo ‘{"foo”: 1, “bar”: 2}’ | jq ‘“(.foo):(.bar)”’|| ||# concat[#concat-note concatenate] _ @< >@||"foo” + “bar”|| ||# translate-case[#translate-case-note translate case]||$ echo ‘“foo”’ | jq ‘ascii_upcase _ $ echo ‘“FOO”’ | jq ‘ascii_downcase’|| ||# num-to-str[#num-to-str-note number to string] _ @< >@||$ echo ‘7’ | jq ‘tostring’|| ||# str-to-num[#str-to-num-note string to number] _ @< >@||$ echo ‘“7”’ | jq ‘tonumber’|| ||# str-join[#str-join-note string join]||##gray|# join is new in 1.4:## _ $ echo ‘[“do”, “re”, “mi”]’ | jq ‘join(“ “)’|| ||# split[#split-note split]||##gray|# split is new in 1.4:## _ $ echo ‘“do re mi”’ | jq ‘split(“ “)’ _ _ ##gray|# remove two empty strings:## _ $ echo ‘“ do re mi”’ | jq ‘split(“ “) | map(select(length > 0))’|| ||# prefix-suffix-test[#prefix-suffix-test-note prefix and suffix test]||$ echo ‘“foobar”’ | jq ‘startswith(“foo”)’ _ $ echo ‘“foobar”’ | jq ‘endswith(“bar”)’|| ||# str-len[#str-len-note string length] _ @< >@||$ jq -R ‘length’ /etc/hosts|| ||# index-substr[#index-substr-note index of substring] _ _ ##gray|//first, last//##||##gray|# 3:## _ $ echo ‘“do re re”’ | jq ‘index(“re”)’ _ _ ##gray|# 6:## _ $ echo ‘“do re re”’ | jq ‘rindex(“re”)’ _ _ ##gray|# null:## _ $ echo ‘“do re re”’ | jq ‘rindex(“mi”)’|| ||||~ # regexregular expressions|| ||~ ||~ jq|| ||# regex-literal[#regex-literal-note literal]||##gray|# regexes are new in 1.5:## _ “lorem|ipsum”|| ||# char-class-abbrev[#char-class-abbrev-note character class abbrevations]||##gray|//but backslashes must be doubled inside double quotes://## _ . \d \D \h \H \s \S \w \W|| ||# anchors[#anchors-note anchors]||##gray|//but backslashes must be doubled inside double quotes://## _ ^ $ \A \b \B \z \Z|| ||# match-test[#match-test-note match test] _ @< >@||$ echo $’"It\’s 1999!”’ | jq ‘. | test(“1999”)’|| ||# case-insensitive-match-test[#case-insensitive-match-test-note case insensitive match test]||$ echo $’"FOO BAR”’ | jq ‘test(“foo”; “i”)’ _ $ echo $’"FOO BAR”’ | jq ‘test([“foo”, “i”])’ _ $ echo $’"FOO BAR”’ | jq ‘test(“(?i)foo”)’|| ||# subst[#subst-note substitution] _ _ ##gray|//first occurrence, all occurrences//##||$ echo ‘“do re mi mi mi”’ | jq ‘sub(“mi”; “ma”)’ _ $ echo ‘“do re mi mi mi”’ | jq ‘gsub(“mi”; “ma”)’|| ||# named-group-capture[#named-group-capture-note named group capture] _ @< >@||$ echo ‘“foo.txt”’ | jq ‘capture(“^(?.)\.(?.)$”) | .root’|| ||||~ # dates-timedates and time|| ||~ ||~ jq|| ||# current-datetime[#current-datetime-note current datetime]||##gray|# date/time functions are new in 1.5## _ _ ##gray|# array of broken-down datetime values:## _ $ jq -n ‘now | gmtime’ _ _ ##gray|# ISO 8601 format:## _ $ jq -n ‘now | gmtime | todate’|| ||# current-unix-epoch[#current-unix-epoch-note current unix epoch] _ @< >@||$ jq -n ‘now’|| ||# broken-down-datetime-to-unix-epoch[#broken-down-datetime-to-unix-epoch-note broken-down datetime to unix epoch]||$ echo ‘[2016,11,15,11,30,0,4,349]’ | jq ‘mktime’|| ||# unix-epoch-to-broken-down-datetime[#unix-epoch-to-broken-down-datetime-note unix epoch to broken-down datetime]||$ echo 1481801400 | jq ‘gmtime’|| ||# fmt-datetime[#fmt-datetime-note format datetime] _ @< >@||$ jq -n ‘now | gmtime | strftime(“%Y-%m-%d %H:%M:%S”)’|| ||# parse-datetime[#parse-datetime-note parse datetime]||##gray|# parses to array of broken-down datetime values:## _ $ echo ‘“2016-12-15 11:30:00”’ | jq ‘strptime(“%Y-%m-%d %H:%M:%S”)’|| ||||~ # arraysarrays|| ||~ ||~ jq|| ||lookup||##gray|# 6:## _ $ echo ‘[6, 7, 8, 9’] | jq ‘.[0]’|| ||not-an-array behavior||##gray|# error:## _ $ echo 1 | jq ‘.[0]’ _ _ ##gray|# no error and no output:## _ $ echo 1 | jq ‘.[0]?’|| ||length||$ echo ‘[6, 7, 8, 9’] | jq ‘length’|| ||slice||##gray|# [7, 8]:## _ $ echo ‘[6,7,8,9]’ | jq ‘.[1:3]’|| ||slice from beginning||$ jq -c ‘.[:2]’|| ||slice to end||##gray|//from element 3 on://## _ $ jq -c ‘.[2:]’ _ _ ##gray|//last two elements://## _ $ jq -c ‘.[-2:]’|| ||indices||$ jq -c ‘keys’|| ||reverse||$ echo ‘[1,2,3]’ | jq ‘reverse’|| ||sort||$ echo ‘[3,1,4,2]’ | jq ‘sort’ || ||dedupe||$ echo ‘[1,1,2,3]’ | jq ‘unique’|| ||subset test||$ echo ‘[1,2,3]’ | jq ‘contains([1])’ _ $ echo ‘[1]’ | jq ‘inside([1,2,3])’ || ||map||$ echo ‘[1,2,3]’ | jq ‘.[] | . * .’ _ $ echo ‘[1,2,3]’ | jq ‘map(. * .)’|| ||filter||$ echo ‘[1,2,3]’ | jq ‘map(select(. > 2))’|| ||reduce||$ echo ‘[1,2,3,4]’| jq ‘reduce .[] as $item (0; .+$item)’|| ||universal and existential test||$ echo ‘[1,2,3]’ | jq ‘all(. > 2)’ _ $ echo ‘[1,2,3]’ | jq ‘any(. > 2)’|| ||flatten _ ##gray|//one level, completely//##||##gray|# flatten is new in 1.5:## _ $ echo ‘[1,[2,[3]]]’ | jq -c ‘flatten(1)’ _ $ echo ‘[1,[2,[3]]]’ | jq -c ‘flatten’|| ||||~ # dictionariesdictionaries|| ||~ ||~ jq|| ||literal||{"t”: 1, “f”: 0}|| ||size||$ echo ‘{"t”: 1, “f”: 0}’ | jq ‘length’|| ||lookup||$ echo ‘{"t”: 1, “f”: 0}’ | jq ‘.t’ _ $ echo ‘{"t”: 1, “f”: 0}’ | jq ‘.[“t”]’|| ||update||$ echo ‘{"t”: 1, “f”: 0}’ | jq ‘.f = -1’|| ||is key present||$ echo ‘{"t”: 1, “f”: 0}’ | jq ‘has(“t”)’ _ $ echo ‘“t”’ | jq ‘in({"t”: 1, “f”: 0})’|| ||missing key behavior||##gray|# null:## _ $ echo ‘{"t”: 1, “f”: 0}’ | jq ‘.m’ || ||not a dictionary behavior||##gray|# error:## _ $ echo 1 | jq ‘.foo’ _ _ ##gray|# no error and no output:## _ $ echo 1 | jq ‘.foo?’|| ||delete||$ echo ‘{"t”: 1, “f”: 0}’ | jq ‘del(.t)’|| ||keys and values as arrays||$ echo ‘{"do”: 1, “re”: 2}’ | jq ‘keys’ _ $ echo ‘{"do”: 1, “re”: 2}’ | jq ‘to_entries | map(.value)’|| ||||~ # functionsfunctions|| ||~ ||~ jq|| ||define||$ echo ‘1 2 3 4’ | jq ‘def double: 2 * .;’|| ||call||$ echo ‘1 2 3 4’ | jq ‘def double: 2 * .; double’|| ||function with argument||$ echo ‘1 2 3 4’ | jq ‘def multiply($x): . * $x; multiply(7)’ _ _ ##gray|# without $, argument is treated as a filter:## _ echo ‘1 2 3 4’ | jq ‘def apply(f): f; apply(. * 7)’|| ||||~ # exec-controlexecution control|| ||~ ||~ jq|| ||if||$ echo ‘-3’ | jq ‘if . < 0 then -. else . end’|| ||while||$ jq -n ‘1 | while(. < 10; . + 1)’ || ||break||$ jq -n ‘1 | label $out | while(true; if . > 10 then break $out else. + 1 end)’|| ||||~ # exceptionsexceptions|| ||~ ||~ jq|| ||raise exception||$ jq -n ‘error(“bam!”)’|| ||handle exception||##gray|# set output to null:## _ $ jq -n ‘try error(“bam!”) catch null’ _ _ ##gray|# two ways to handle with no output:## _ $ jq -n ‘try error(“bam!”) catch empty’ _ $ jq -n ‘error(“bam!”)?’|| ||||~ # streamsstreams|| ||~ ||~ jq|| ||write to stderr||##gray|# input to debug is also passed on to subsequent filters:## _ $ jq -n ‘“foo” | debug’|| ||read input as array of strings||$ jq -R ‘length’ /etc/hosts|| ||array to stream||$ echo ‘[1,2,3]’ | jq ‘.[]’|| ||stream to array||$ echo ‘1 2 3’ | jq -s ‘.’|| ||||~ # file-fmtfile formats|| ||~ ||~ jq|| ||||~ # processes-envprocesses and environment|| ||~ ||~ jq|| ||environment variable||$ jq -n ‘env.HOME’ _ $ jq -n ‘env[“HOME”]’|| ||||~ # lib-namespaceslibraries and namespaces|| ||~ ||~ jq|| ||load library||$ cat > multiples.jq _ def double: 2 * .; _ def triple: 3 * .; _ def quadruple; 4 * .; _ _ $ echo 3 | jq ‘include “multiples”; double’|| ||library path command line option||$ mkdir ~/.jq _ $ cat > ~/.jq/multiples.jq _ def double: 2 * .; _ def triple: 3 * .; _ def quadruple; 4 * .; _ _ $ echo 3 | jq -L ~/.jq ‘include “multiples”; double’|| ||load definitions in namespace||$ cat > multiples.jq _ def double: 2 * .; _ def triple: 3 * .; _ def quadruple; 4 * .; _ _ $ echo 3 | jq ‘import “multiples” as mult; mult::double’|| ||||~ # reflectionreflection|| ||~ ||~ jq|| ||# inspect-type[#inspect-type-note inspect type]||$ echo ‘{"foo”: 1}’ | jq ‘.foo | type’|| ||# basic-types[#basic-types-note basic types]||"number” _ “boolean” _ “array” _ “object” _ “null” _ “string”|| ||~ ||~ ##EFEFEF|@@___________________________________________________________________@@##||

# jq + Jq

[http://manpages.ubuntu.com/manpages/xenial/man1/jq.1.html jq man page]

{{jq}} programs transform streams of JSON data.

[[# jsonnet] + Jsonnet

[https://jsonnet.org/ jsonnet.org]

Jsonnet is an extension of JSON which adds variables and functions (hygienic macros). The Jsonnet iterpreter converts a Jsonnet program to JSON.