Jq: Using Variables in shell script

[kboghdady]

How I can use shell variables on the jq command
For example
ID="THE_ID: .ID"
jq '. |{ $ID}' file.json

any ideas ?

[nicowilliams]

See the --arg and --arg-file arguments.

[kboghdady]

Thanks Nico for your prompt reply ..
I have tried jq --arg ID "THE_ID: .ID"" file.son -- and it didn't work
and basically my aim is to use several variable in bash to be the query arguments of jq as $ID

[wtlangford]

What does "THE_ID: .ID" mean to you, exactly? The way --arg works is as
follows: --arg ARGNAME ARGVALUE. Then in your jq program you can say
"$ARGNAME" to reference the value.
Also, can we have a slightly more concrete example of what you're trying to
do?

On Mon, Nov 24, 2014 at 6:11 PM, kboghdady [email protected] wrote:

Thanks Nico for your prompt reply ..
I have tried jq --arg ID "THE_ID: .ID"" file.son -- and it didn't work
and basically my aim is to use several variable in bash to be the query
arguments of jq as $ID

—
Reply to this email directly or view it on GitHub
https://github.com/stedolan/jq/issues/626#issuecomment-64282555.

[nicowilliams]

I have tried jq --arg ID "THE_ID: .ID"" file.son -- and it didn't work
and basically my aim is to use several variable in bash to be the query
arguments of jq as $ID

The --arg variable values are always taken to be strings. Which means
that { $ID } is not a valid jq expression.

[pkoppstein]

See also the FAQ - General Questions (https://github.com/stedolan/jq/wiki/FAQ#general-questions)

[ghost]

If you want whatever you pass as argument to be evaluated as a JSON object, you can pipe it to fromjson inside your jq script. For example, on a bash-like shell:

export FOO='{"a": 1, "b": 2}'
jq -n --arg foo "$FOO" '$foo | fromjson + {"c": 3}'

[kboghdady]

Thanks a lot for all the replies ..
I have fixed it by changing the ' to " so it could interrupt the value of $ID
jq ". [] | { $ID}" file.json

[espoelstra]

Also note that when you are using single quotes around the jq query, you should NOT double quote around jq --arg variables within the query, it confuses and breaks things. This "shell-ism" is a habit that tripped me up in jq.

This first example would work:

projectID=$(cat file.json | jq -r --arg EMAILID "$EMAILID" '.resource[]
                               | select(.username==$EMAILID) | .id')

This second example probably wouldn't:

projectID=$(cat file.json | jq -r --arg EMAILID "$EMAILID" '.resource[]
                               | select(.username=="$EMAILID") | .id')

[higkoo]

jq '."media"."track"[] | select(."@type"=="General") | ."Encoded_Application"'

output: "Lavf56.40.101"

{ "media": { "@ref": "2016-07-13_03-01-49.flv", "track": [ { "@type": "General", "VideoCount": "1", "AudioCount": "1", "FileExtension": "flv", "Format": "Flash Video", "FileSize": "739869", "Duration": "2.233", "OverallBitRate": "2650673", "FrameRate": "30.000", "FrameCount": "67", "File_Modified_Date": "UTC 2016-07-12 19:01:52", "File_Modified_Date_Local": "2016-07-13 03:01:52", "Encoded_Application": "Lavf56.40.101" }, { "@type": "Video", "Format": "AVC", "Format_Profile": "Main", "Format_Level": "3.1", "Format_Settings_CABAC": "Yes", "Format_Settings_RefFrames": "4", "CodecID": "7", "Duration": "2.233", "BitRate": "2500000", "Width": "1280", "Height": "720", "Sampled_Width": "1280", "Sampled_Height": "720", "PixelAspectRatio": "1.000", "DisplayAspectRatio": "1.778", "FrameRate_Mode": "CFR", "FrameRate": "30.000", "FrameCount": "67", "ColorSpace": "YUV", "ChromaSubsampling": "4:2:0", "BitDepth": "8", "ScanType": "Progressive", "Delay": "0.000", "StreamSize": "697812", "Encoded_Library": "x264 - core 142", "Encoded_Library_Name": "x264", "Encoded_Library_Version": "core 142", "Encoded_Library_Settings": "cabac=1 / ref=1 / deblock=1:0:0 / analyse=0x1:0x111 / me=hex / subme=2 / psy=1 / psy_rd=1.00:0.00 / mixed_ref=0 / me_range=16 / chroma_me=1 / trellis=0 / 8x8dct=0 / cqm=0 / deadzone=21,11 / fast_pskip=1 / chroma_qp_offset=0 / threads=12 / lookahead_threads=4 / sliced_threads=0 / nr=0 / decimate=1 / interlaced=0 / bluray_compat=0 / constrained_intra=0 / bframes=3 / b_pyramid=2 / b_adapt=1 / b_bias=0 / direct=1 / weightb=1 / open_gop=0 / weightp=1 / keyint=120 / keyint_min=12 / scenecut=40 / intra_refresh=0 / rc_lookahead=10 / rc=cbr / mbtree=1 / bitrate=2500 / ratetol=1.0 / qcomp=0.60 / qpmin=0 / qpmax=69 / qpstep=4 / vbv_maxrate=2500 / vbv_bufsize=2500 / nal_hrd=none / filler=1 / ip_ratio=1.40 / aq=1:1.00" }, { "@type": "Audio", "Format": "AAC", "Format_AdditionalFeatures": "LC", "CodecID": "10-2", "Duration": "2.229", "BitRate": "156250", "Channels": "2", "ChannelPositions": "Front: L R", "ChannelLayout": "L R", "SamplesPerFrame": "1024", "SamplingRate": "44100", "SamplingCount": "98299", "FrameRate": "43.066", "Compression_Mode": "Lossy", "Delay": "0.000", "Delay_Source": "Container", "StreamSize": "43535", "StreamSize_Proportion": "0.05884" } ] } }