jq_proto.sh

# Prototypical statements for the json-processing command line tool `jq`.
#
# author: andreasl

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# command line args

# jq -r   # remove quotation marks from output; don't parse input as json, instead, each line is passed to the filter as a string.

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# treat an array of jsons as several individual jsons

cat myarrayfile.json | jq '.[]'  # many json objects, without comma between them


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# output json items in 1 row each

cat myndjsonfile.json | jq -c  # output every document on 1 line



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# select stuff and filter

cat myarrayfile.json | jq -r '.[] | .location'   # get the location fields without quotation marks

cat myarrayfile.json | jq '.[] | select(.state == "some_state") | "\(.loc), \(.sku)"'
cat myndjsonfile.json | jq 'select(.state == "some_state") | "\(.loc), \(.sku)"'      # for newline-delimited json

# more complicated query
cat myndjsonfile.json | jq 'select((.main_image | length > 0) and .location_code != null)'


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# get distinct values
cat myfile.json | jq 'map(.myfield) | unique'  # jq-ish way
cat myarrayfile.json | jq '.[] | .state' | sort -u  # bash-y way


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# count

# count array lenghts
cat myarrayfile.json | jq 'map(.myfield) | unique | length'


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# grouping

# group all json objects with the same value for `myfield` into arrays, yielding several arrays
cat myarrayfile.json| jq 'group_by(.myfield)'