updated jq (#107)

sheets/jq

@@ -20,72 +20,134 @@ jq .[0].key_name
 # Output the value of a given key of each element in a JSON file:
 jq 'map(.key_name)'
 #
-# [ { foo: 1 }, { foo: 2 } ] => [1, 2]
+#     [ { foo: 1 }, { foo: 2 } ]
+#     => [1, 2]
 
 # Extract as stream of values instead of a list
 jq '.[] | .foo'
 #
-# [ { "foo": 1 }, { "foo": 2 } ] => 1, 2
+#     [ { "foo": 1 }, { "foo": 2 } ]
+#     => 1, 2
 
 # Slicing
 jq '.[1:2]'
 #
-# [ { "foo": 1 }, { "foo": 2 } ] => { "foo": 2 }
+#     [ { "foo": 1 }, { "foo": 2 } ]
+#     => { "foo": 2 }
 
 # Dictionary subset shorthand
 jq 'map({ a, b })'
 #
-# [ { "a": 1, "b": 2, "c": 3 }, ...] => [ { "a": 1, "b": 2 }, ...]
+#     [ { "a": 1, "b": 2, "c": 3 }, ...]
+#     => [ { "a": 1, "b": 2 }, ...]
 
-# Parsing json
-jq 'with_entries(.value |= fromjson)' --sort-keys
+# Converting arbitrary data to json
+jq -r '(map(keys) | add | unique | sort) as $cols | .[] as $row | $cols | map($row[.]) | @csv'
 #
-# { "b": "{}", "a": "{}" }
-#   =>  { "a": {}, "b": {} }
-
-# Serializing json
+#     [ { "foo": 1, "bar": 2}, { "foo": 3, "baz": 4}]
 #
-jq 'with_entries(.value |= tojson)' --sort-keys
+#     => 2,,1
+#      ,4,3
+
+# Filter a list of objects
+jq 'map(select(.name == "foo"))'
 #
-# { "a": {}, "b": {} }
-# => { "a": "{}", "b": "{}" }
+#     [ { "name": "foo" }, { "name": "bar" } ]
+#     => [ { "name": "foo" } ]
 
-# Flattening json
-jq 'flatten(1)'
 #
-# [[1], [2]]
-# => [1, 2]
+#     ## mapping and transforming ##
+#
 
-# Converting to csv
-jq '.[] | [.foo, .bar] | @csv' -r
+# Add + 1 to all items
+jq 'map(.+1)'
+
+# Delete 2 items
+jq 'del(.[1, 2])'
+
+# Concatenate arrays
+jq 'add'
+
+# Flatten an array
+jq 'flatten'
 #
-# [{ "foo": 1, "bar": 2, "baz":3 }]
-# => 1,2
+#     [[1], [2]]
+#     => [1, 2]
 
-# Sort
-jq 'sort'
-# [3, 2, 1]
-# => [1, 2, 3]
+# Create a range of numbers
+jq '[range(2;4)]'
+
+# Display the type of each item
+jq 'map(type)'
 
-# Deleting duplicates (dedup / uniq)
-jq unique
+# Sort an array of basic type
+jq 'sort'
 #
-# [1, 1, 2, 1]
-# => [1, 2]
+#     [3, 2, 1]
+#     => [1, 2, 3]
+
+# Sort an array of objects
+jq 'sort_by(.foo)'
 
 # Sort lines of a file
 jq --slurp '. | sort | .[]'
 
-# Converting arbitrary data to json
-jq -r '(map(keys) | add | unique | sort) as $cols | .[] as $row | $cols | map($row[.]) | @csv'
-# [ { "foo": 1, "bar": 2}, { "foo": 3, "baz": 4}]
+# Group by a key - opposite to flatten
+jq 'group_by(.foo)'
+
+# Minimun value of an array
+jq 'min'
+# See also min, max, min_by(path_exp), max_by(path_exp)
+
+# Remove duplicates
+jq 'unique'
+# or
+jq 'unique_by(.foo)'
+# or
+jq 'unique_by(length)'
 #
-# => 2,,1
-#    ,4,3
+#   [1, 1, 2, 1]
+#   => [1, 2]
 
-# Filter a list of objects
-jq 'map(select(.name == "foo"))'
+# Reverse an array
+jq 'reverse'
+
+# 
+#   ## jq in shell scripts ##
+#
+
+# URL Encode something
+date | jq -sRr @uri
+# Thu%2021%20May%202020%2012%3A40%3A40%20PM%20CEST%0A
+
+# To create proper JSON from a shell script and properly escape variables:
+jq -n --arg foobaz "$FOOBAZ" '{"foobaz":$foobaz}'
+
+# To fill environment variables from JSON object keys
+# (e.g. $FOO from jq query ".foo")
+export $(jq -r '@sh "FOO=\(.foo) BAZ=\(.baz)"')
+
+
+# 
+#   ## Input/output formats ##
+#
+
+# Parsing json
+jq 'with_entries(.value |= fromjson)' --sort-keys
+#
+#     { "b": "{}", "a": "{}" }
+#     =>  { "a": {}, "b": {} }
+
+# Serializing json
+#
+jq 'with_entries(.value |= tojson)' --sort-keys
+#
+#     { "a": {}, "b": {} }
+#     => { "a": "{}", "b": "{}" }
+
+# Converting to csv
+jq '.[] | [.foo, .bar] | @csv' -r
 #
-# [ { "name": "foo" }, { "name": "bar" } ]
-# => [ { "name": "foo" } ]
+#     [{ "foo": 1, "bar": 2, "baz":3 }]
+#     => 1,2