jq How to pass key starting with numeral as argument [duplicate] - bash

I am new to jq and facing an issue while parsing my json
I have a json stored in a variable like this
temp='{ "1": { "my_name": "one" }, "2": { "my_name": "two" } }'
Now I need to get the value of my_name for both other entries
I have tried something like this
echo $temp | jq '.1' //out put 0.1
I was assuming to get { "my_name": "one" }
And similarly to get my_name value I did
echo $temp | jq '.1.my_name' // Its output is giving me error
Can any one please help to identify what is wrong with my syntax and how can I correct it.

Just the number gets interpreted as a float. You need to use it in a context where it is unambiguously a key string.
echo "$temp" | jq '.["1"]["my_name"]'
and
echo "$temp" | jq '.["1"]'
to get the containing dict.
With a sufficiently new jq (I think >= 1.4) you can also say
echo "$temp" | jq '."1".my_name'

Whenever you are trying to reference a key that is not a valid identifier, you have to quote it. See the manual for more details.
To select the item under the key 1, you'd do this:
."1"
For your other question on how to obtain the my_name values, you could do this:
to_entries | map(.value.my_name)

Related

Bash: Issue when iterating string with lines [duplicate]

I have a JSON data as follows in data.json file
[
{"original_name":"pdf_convert","changed_name":"pdf_convert_1"},
{"original_name":"video_encode","changed_name":"video_encode_1"},
{"original_name":"video_transcode","changed_name":"video_transcode_1"}
]
I want to iterate through the array and extract the value for each element in a loop. I saw jq. I find it difficult to use it to iterate. How can I do that?
Just use a filter that would return each item in the array. Then loop over the results, just make sure you use the compact output option (-c) so each result is put on a single line and is treated as one item in the loop.
jq -c '.[]' input.json | while read i; do
# do stuff with $i
done
By leveraging the power of Bash arrays, you can do something like:
# read each item in the JSON array to an item in the Bash array
readarray -t my_array < <(jq --compact-output '.[]' input.json)
# iterate through the Bash array
for item in "${my_array[#]}"; do
original_name=$(jq --raw-output '.original_name' <<< "$item")
changed_name=$(jq --raw-output '.changed_name' <<< "$item")
# do your stuff
done
jq has a shell formatting option: #sh.
You can use the following to format your json data as shell parameters:
cat data.json | jq '. | map([.original_name, .changed_name])' | jq #sh
The output will look like:
"'pdf_convert' 'pdf_convert_1'"
"'video_encode' 'video_encode_1'",
"'video_transcode' 'video_transcode_1'"
To process each row, we need to do a couple of things:
Set the bash for-loop to read the entire row, rather than stopping at the first space (default behavior).
Strip the enclosing double-quotes off of each row, so each value can be passed as a parameter to the function which processes each row.
To read the entire row on each iteration of the bash for-loop, set the IFS variable, as described in this answer.
To strip off the double-quotes, we'll run it through the bash shell interpreter using xargs:
stripped=$(echo $original | xargs echo)
Putting it all together, we have:
#!/bin/bash
function processRow() {
original_name=$1
changed_name=$2
# TODO
}
IFS=$'\n' # Each iteration of the for loop should read until we find an end-of-line
for row in $(cat data.json | jq '. | map([.original_name, .changed_name])' | jq #sh)
do
# Run the row through the shell interpreter to remove enclosing double-quotes
stripped=$(echo $row | xargs echo)
# Call our function to process the row
# eval must be used to interpret the spaces in $stripped as separating arguments
eval processRow $stripped
done
unset IFS # Return IFS to its original value
From Iterate over json array of dates in bash (has whitespace)
items=$(echo "$JSON_Content" | jq -c -r '.[]')
for item in ${items[#]}; do
echo $item
# whatever you are trying to do ...
done
Try Build it around this example. (Source: Original Site)
Example:
jq '[foreach .[] as $item ([[],[]]; if $item == null then [[],.[0]] else [(.[0] + [$item]),[]] end; if $item == null then .[1] else empty end)]'
Input [1,2,3,4,null,"a","b",null]
Output [[1,2,3,4],["a","b"]]
None of the answers here worked for me, out-of-the-box.
What did work was a combination of a few:
projectList=$(echo "$projRes" | jq -c '.projects[]')
IFS=$'\n' # Read till newline
for project in ${projectList[#]}; do
projectId=$(jq '.id' <<< "$project")
projectName=$(jq -r '.name' <<< "$project")
...
done
unset IFS
NOTE: I'm not using the same data as the question does, in this example assume projRes is the output from an API that gives us a JSON list of projects, eg:
{
"projects": [
{"id":1,"name":"Project"},
... // array of projects
]
}
An earlier answer in this thread suggested using jq's foreach, but that may be much more complicated than needed, especially given the stated task. Specifically, foreach (and reduce) are intended for certain cases where you need to accumulate results.
In many cases (including some cases where eventually a reduction step is necessary), it's better to use .[] or map(_). The latter is just another way of writing [.[] | _] so if you are going to use jq, it's really useful to understand that .[] simply creates a stream of values.
For example, [1,2,3] | .[] produces a stream of the three values.
To take a simple map-reduce example, suppose you want to find the maximum length of an array of strings. One solution would be [ .[] | length] | max.
Here is a simple example that works in zch shell:
DOMAINS='["google","amazon"]'
arr=$(echo $DOMAINS | jq -c '.[]')
for d in $arr; do
printf "Here is your domain: ${d}\n"
done
I stopped using jq and started using jp, since JMESpath is the same language as used by the --query argument of my cloud service and I find it difficult to juggle both languages at once. You can quickly learn the basics of JMESpath expressions here: https://jmespath.org/tutorial.html
Since you didn't specifically ask for a jq answer but instead, an approach to iterating JSON in bash, I think it's an appropriate answer.
Style points:
I use backticks and those have fallen out of fashion. You can substitute with another command substitution operator.
I use cat to pipe the input contents into the command. Yes, you can also specify the filename as a parameter, but I find this distracting because it breaks my left-to-right reading of the sequence of operations. Of course you can update this from my style to yours.
set -u has no function in this solution, but is important if you are fiddling with bash to get something to work. The command forces you to declare variables and therefore doesn't allow you to misspell a variable name.
Here's how I do it:
#!/bin/bash
set -u
# exploit the JMESpath length() function to get a count of list elements to iterate
export COUNT=`cat data.json | jp "length( [*] )"`
# The `seq` command produces the sequence `0 1 2` for our indexes
# The $(( )) operator in bash produces an arithmetic result ($COUNT minus one)
for i in `seq 0 $((COUNT - 1))` ; do
# The list elements in JMESpath are zero-indexed
echo "Here is element $i:"
cat data.json | jp "[$i]"
# Add or replace whatever operation you like here.
done
Now, it would also be a common use case to pull the original JSON data from an online API and not from a local file. In that case, I use a slightly modified technique of caching the full result in a variable:
#!/bin/bash
set -u
# cache the JSON content in a stack variable, downloading it only once
export DATA=`api --profile foo compute instance list --query "bar"`
export COUNT=`echo "$DATA" | jp "length( [*] )"`
for i in `seq 0 $((COUNT - 1))` ; do
echo "Here is element $i:"
echo "$DATA" | jp "[$i]"
done
This second example has the added benefit that if the data is changing rapidly, you are guaranteed to have a consistent count between the elements you are iterating through, and the elements in the iterated data.
This is what I have done so far
arr=$(echo "$array" | jq -c -r '.[]')
for item in ${arr[#]}; do
original_name=$(echo $item | jq -r '.original_name')
changed_name=$(echo $item | jq -r '.changed_name')
echo $original_name $changed_name
done

Converting JSON response to key value pair using jq

So, I am getting a response from an API that I am calling in a shell script in the following form
[{"id":100000004,"name":"Customs Clearance Requested"},{"id":100000005,"name":"Customs Cleared"},{"id":100000006,"name":"Cargo Loaded to Vessel"}]
I want to create a map out of it that will help me lookup the id's from a name and use it in the shell script. So something like map["Customs Clearance Requested"] would give me 100000004 which I can use further. Can this be done using jq? I am pretty new to shell scripting and jq and got stuck with above thing
json='[{"id":100000004,"name":"Customs Clearance Requested"},{"id":100000005,"name":"Customs Cleared"},{"id":100000006,"name":"Cargo Loaded to Vessel"}]'
declare -A map
while IFS= read -r -d '' name && IFS= read -r -d '' value; do
map[$name]=$value
done < <(jq -j '.[] | "\(.name)\u0000\(.id)\u0000"' <<<"$json")
declare -p map # demo purposes: print the map we created as output
...emits as output:
declare -A map=(["Cargo Loaded to Vessel"]="100000006" ["Customs Clearance Requested"]="100000004" ["Customs Cleared"]="100000005" )
...which you can query exactly as requested:
$ echo "${map['Cargo Loaded to Vessel']}"
100000006
You could use the select function, e.g.:
data='[{"id":100000004,"name":"Customs Clearance Requested"},{"id":100000005,"name":"Customs Cleared"},{"id":100000006,"name":"Cargo Loaded to Vessel"}]'
jq 'map(select(.["name"] == "Customs Clearance Requested"))' <<< $data
It will get all elements which name equals "Customs Clearance Requested", e.g.:
[
{
"id": 100000004,
"name": "Customs Clearance Requested"
}
]
If you want to get the id field:
jq 'map(select(.["name"] == "Customs Clearance Requested")["id"])' <<< $data
This will output:
[
100000004
]
Please note that it will return an array and not a single element because the search does not know how many results will be found.
If you want to generalize this in a shell function, you could write:
function get_id_from_name
{
# $1=name to search for
local filter=$(printf 'map(select(.["name"] == "%s")["id"])' "$1")
jq "$filter"
}
Then call it like that:
get_id_from_name "Customs Clearance Requested" <<< $data
If your data is stored in a file, you could call it this way:
get_id_from_name "Customs Clearance Requested" < /path/to/file.json
The following is very similar to #CharlesDuffy's excellent answer but does not assume that the .name and .id values are NUL-free (i.e., do not have any "\u0000" characters):
declare -A map
while read -r name
do
name=$(sed -e 's/^"//' -e 's/"$//' <<< "$name")
read -r id
map[$name]="$id"
done < <(echo "$json" | jq -c '.[]|.name,.id')
The point is that the -j option is like -r (i.e., produces "raw output"), whereas the -c option produces JSON.
This means that if you don't want the .id values as JSON strings, then the above won't be a solution; also, if the .name values contain double-quotes, then you might want to deal with the occurrences of \".

How to replace a variable inside a string in bash

I have a string env variable which looks like below
data={\"data\":{\"sources\":\"some value\", \"destination\":\"some other value\"}}
I would like to include date (say YEAR) within this env variable. That is, I have another env variable called YEAR (bash: YEAR=2019) and I would like to use this variable (YEAR) inside data. Here is what I need to do
data={\"data\":{\"sources\":\"some value ${YEAR}\", \"destination\":\"some other value\"}}
but it does not work, how can I make it work?
Use jq:
$ echo "$data" | jq --argjson y "$YEAR" '.data.sources += " \($y)"'
{
"data": {
"sources": "some value 2019",
"destination": "some other value"
}
}
or
# Note the -c argument to compress the data to a single line
$ data=$(echo "$data" | jq -c --argjson y "$YEAR" '.data.sources += " \($y)"')
$ echo "$data"
{"data":{"sources":"some value 2019","destination":"some other value"}}
Alternative, using here documents, minimizing the need to escape quotes, while still supporting variable substitutions:
data=$(cat <<DATA
"data": {
"sources":"some value ${YEAR}",
"destination":"some other value"
}
}
DATA
)

JQ get key based on variable value

I'm trying to create a ohmyzsh function for Salesforce's DX CLI based on Wade Wegner's guide here. In order to get the value I want I need to expand how he is using JQ which I've never heard of before. I get the premise for this use case but I'm struggling with one abstraction point (within the aliasConfig json). Here's my script so far
get_sfdx_defaultusername() {
config="$(cat .sfdx/sfdx-config.json 2> /dev/null)";
globalConfig="$(cat ~/.sfdx/sfdx-config.json)";
aliasConfig="$(cat ~/.sfdx/alias.json)";
defaultusername="$(echo ${config} | jq -r .defaultusername)"
defaultusernamealias="NEED HELP HERE"
globaldefaultusername="$(echo ${globalConfig} | jq -r .defaultusername)"
if [ ! $defaultusernamealias = "null" ]
then
echoString=$echoString$defaultusernamealias"$txtylw (alias)"
elif [ ! $defaultusername = "null" ]
then
echoString=$echoString$defaultusername"$txtylw (local)"
else
echoString=$echoString$globaldefaultusername"$txtylw (global)"
fi
echo $echoString"\n"
}
The alias.json looks like this:
{
"orgs": {
"HubOrg": "myemail#domain.com",
"my-scrath-org": "test-jdj1iflkor4k#mydomain.net"
}
}
Using the ${defaultusername} I know the value in this case to be "test-jdj1iflkor4k#mydomain.net", therefore I need it to set the value of defaultusernamealias to "my-scrath-org"
NOTE: The closest answer I found was this, but unfortunately I still couldn't get what I needed with it.
Congratulations on figuring out how to use to_entries.
One small suggestion is to avoid using shell interpolation to "construct" the jq program. A much better way to achieve the desired goal is to pass in the relevant values on the command-line. In your case, the following would be appropriate:
$ jq --arg username "$defaultusername" '
.orgs | to_entries[] | select(.value == $username ).key'
Another small point is to avoid using echo to send JSON to STDIN. There are several possibilities, including these patterns:
if you are using bash: jq .... <<< "$JSON"
use printf "%s" "$JSON" | jq ...
jq -n --argjson JSON "$JSON" '$JSON | ...'
In your case, the last of these alternatives would look like this:
$ jq --arg username "$defaultusername" --argjson JSON "$aliasConfig" '
$JSON
| .orgs | to_entries[] | select(.value == $username ).key'
I think I got it figured out here:
get_sfdx_defaultusername() {
config="$(cat .sfdx/sfdx-config.json 2> /dev/null)";
globalConfig="$(cat ~/.sfdx/sfdx-config.json)";
aliasConfig="$(cat ~/.sfdx/alias.json)";
defaultusername="$(echo ${config} | jq -r .defaultusername)"
defaultusernamealias="$(echo ${aliasConfig} | jq -r '.orgs | to_entries[] | select(.value =="'$defaultusername'").key' )"
globaldefaultusername="$(echo ${globalConfig} | jq -r .defaultusername)"
if [ ! $defaultusernamealias = "null" ]
then
echoString=$echoString$defaultusernamealias"$txtylw (alias)"
elif [ ! $defaultusername = "null" ]
then
echoString=$echoString$defaultusername"$txtylw (local)"
else
echoString=$echoString$globaldefaultusername"$txtylw (global)"
fi
echo $echoString"\n"
}
This allows me to show my current defaultusername org like so:
In case anyone is interested in using this or contributing to it, I published a github repo here

using jq to assign multiple output variables

I am trying to use jq to parse information from the TVDB api. I need to pull a couple of fields and assign the values to variables that I can continue to use in my bash script. I know I can easily assign the output to one variable through bash with variable="$(command)" but I need the output to produce multiple variables and I don't want to make to use multiple commands.
I read this documentation:
https://stedolan.github.io/jq/manual/v1.5/#Advancedfeatures
but I don't know if this relevant to what I am trying to do.
jq '.data' produces the following output:
[
{
"absoluteNumber": 51,
"airedEpisodeNumber": 6,
"airedSeason": 4,
"airedSeasonID": 680431,
"dvdEpisodeNumber": 6,
"dvdSeason": 4,
"episodeName": "We Will Rise",
"firstAired": "2017-03-15",
"id": 5939660,
"language": {
"episodeName": "en",
"overview": "en"
},
"lastUpdated": 1490769062,
"overview": "Clarke and Roan must work together in hostile territory in order to deliver an invaluable asset to Abby and her team."
}
]
I tried jq '.data | {episodeName:$name}' and jq '.data | .episodeName as $name' just to try and get one working. I don't understand the documentation or even if it's what I'm looking for. Is there a way to do what I am trying to do?
You can use separate variables with read :
read var1 var2 var3 < <(echo $(curl -s 'https://api.github.com/repos/torvalds/linux' |
jq -r '.id, .name, .full_name'))
echo "id : $var1"
echo "name : $var2"
echo "full_name : $var3"
Using array :
read -a arr < <(echo $(curl -s 'https://api.github.com/repos/torvalds/linux' |
jq -r '.id, .name, .full_name'))
echo "id : ${arr[0]}"
echo "name : ${arr[1]}"
echo "full_name : ${arr[2]}"
Also you can split jq output with some character :
IFS='|' read var1 var2 var3 var4 < <(curl '......' | jq -r '.data |
map([.absoluteNumber, .airedEpisodeNumber, .episodeName, .overview] |
join("|")) | join("\n")')
Or use an array like :
set -f; IFS='|' data=($(curl '......' | jq -r '.data |
map([.absoluteNumber, .airedEpisodeNumber, .episodeName, .overview] |
join("|")) | join("\n")')); set +f
absoluteNumber, airedEpisodeNumber, episodeName & overview are respectively ${data[0]}, ${data[1]}, ${data[2]}, ${data[3]}. set -f and set +f are used to respectively disable & enable globbing.
For the jq part, all your required fields are mapped and delimited with a '|' character with join("|")
If your are using jq < 1.5, you'll have to convert Number to String with tostring for each Number fields eg:
IFS='|' read var1 var2 var3 var4 < <(curl '......' | jq -r '.data |
map([.absoluteNumber|tostring, .airedEpisodeNumber|tostring, .episodeName, .overview] |
join("|")) | join("\n")')
jq always produces a stream of zero or more values. For example, to produce the two values corresponding to "episodeName" and "id"' you could write:
.data[] | ( .episodeName, .id )
For your purposes, it might be helpful to use the -c command-line option, to ensure each JSON output value is presented on a single line. You might also want to use the -r command-line option, which removes the outermost quotation marks from each output value that is a JSON string.
For further variations, please see the jq FAQ https://github.com/stedolan/jq/wiki/FAQ, e.g. the question:
Q: How can a stream of JSON texts produced by jq be converted into a bash array of corresponding values?
Experimental conversion of quoted OP input, (tv.dat), to a series of bash variables, (and an array). The jq code is mostly borrowed from here and there, but I don't know how to get jq to unroll an array within an array, so the sed code does that, (that's only good for one level, but so are bash arrays):
jq -r ".[] | to_entries | map(\"DAT_\(.key) \(.value|tostring)\") | .[]" tv.dat |
while read a b ; do echo "${a,,}='$b'" ; done |
sed -e '/{.*}/s/"\([^"]*\)":/[\1]=/g;y/{},/() /' -e "s/='(/=(/;s/)'$/)/"
Output:
dat_absolutenumber='51'
dat_airedepisodenumber='6'
dat_airedseason='4'
dat_airedseasonid='680431'
dat_dvdepisodenumber='6'
dat_dvdseason='4'
dat_episodename='We Will Rise'
dat_firstaired='2017-03-15'
dat_id='5939660'
dat_language=([episodeName]="en" [overview]="en")
dat_lastupdated='1490769062'
dat_overview='Clarke and Roan must work together in hostile territory in order to deliver an invaluable asset to Abby and her team.'

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