json 将 bash 变量传递给 jq select
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Passing bash variable to jq select
提问by asidd
I have written a script to retrieve certain value from file.json. It works if I provide the value to jq select, but the variable doesn't seem to work (or I don't know how to use it).
我编写了一个脚本来从file.json. 如果我将值提供给 jq select，它会起作用，但该变量似乎不起作用（或者我不知道如何使用它）。
#!/bin/sh
#this works ***
projectID=$(cat file.json | jq -r '.resource[] | select(.username=="[email protected]") | .id')
echo "$projectID"
[email protected]
#this does not work *** no value is printed
projectID=$(cat file.json | jq -r '.resource[] | select(.username=="$EMAILID") | .id')
echo "$projectID"
回答by peak
Consider also passing in the shell variable (EMAILID) as a jq variable (here also EMAILID, for the sake of illustration):
还考虑传入 shell 变量 (EMAILID) 作为 jq 变量（这里也是 EMAILID，为了说明）：
projectID=$(cat file.json |
jq -r --arg EMAILID "$EMAILID" '
.resource[]
| select(.username==$EMAILID)
| .id')
Postscript
后记
For the record, another possibility would be to use jq's envfunction for accessing environment variables. For example, consider this sequence of bash commands:
作为记录，另一种可能性是使用 jq 的env函数来访问环境变量。例如，请考虑以下 bash 命令序列：
[email protected] # not exported
EMAILID="$EMAILID" jq -n 'env.EMAILID'
The output is a JSON string:
输出是一个 JSON 字符串：
"[email protected]"
回答by asidd
I resolved this issue by escaping the inner double quotes
我通过转义内部双引号解决了这个问题
projectID=$(cat file.json | jq -r ".resource[] | select(.username==\"$EMAILID\") | .id")
回答by Gilles Quenot
It's a quote issue, you need :
这是一个报价问题，您需要：
projectID=$(
cat file.json | jq -r ".resource[] | select(.username=='$EMAILID') | .id"
)
If you put single quotesto delimit the main string, the shell takes $EMAILIDliterally.
如果用单引号分隔主字符串，shell 会按$EMAILID字面意思处理。
"Double quote" every literal that contains spaces/metacharacters and everyexpansion: "$var", "$(command "$var")", "${array[@]}", "a & b". Use 'single quotes'for code or literal $'s: 'Costs $5 US', ssh host 'echo "$HOSTNAME"'. See
http://mywiki.wooledge.org/Quotes
http://mywiki.wooledge.org/Arguments
http://wiki.bash-hackers.org/syntax/words
“双引号”包含空格/元字符和每个扩展的每个文字："$var", "$(command "$var")", "${array[@]}", "a & b". 使用'single quotes'代码或文字$'s: 'Costs $5 US'，ssh host 'echo "$HOSTNAME"'。请参阅
http://mywiki.wooledge.org/Quotes
http://mywiki.wooledge.org/Arguments
http://wiki.bash-hackers.org/syntax/words
回答by Andrew Lockhart
Another way to accomplish this is with the jq "--arg" flag. Using the original example:
实现此目的的另一种方法是使用 jq "--arg" 标志。使用原始示例：
#!/bin/sh
#this works ***
projectID=$(cat file.json | jq -r '.resource[] |
select(.username=="[email protected]") | .id')
echo "$projectID"
[email protected]
# Use --arg to pass the variable to jq. This should work:
projectID=$(cat file.json | jq --arg EMAILID $EMAILID -r '.resource[]
| select(.username=="$EMAILID") | .id')
echo "$projectID"
See here, which is where I found this solution: https://github.com/stedolan/jq/issues/626
看到这里，这是我找到这个解决方案的地方：https: //github.com/stedolan/jq/issues/626
回答by Zaid
Posting it here as it might help others. In string it might be necessary to pass the quotes to jq. To do the following with jq:
在这里发布它，因为它可能会帮助其他人。在字符串中，可能需要将引号传递给 jq。使用 jq 执行以下操作：
.items[] | select(.name=="string")
in bash you could do
在 bash 你可以做
EMAILID=
projectID=$(cat file.json | jq -r '.resource[] | select(.username=='\"$EMAILID\"') | .id')
essentially escaping the quotes and passing it on to jq
基本上转义引号并将其传递给 jq
回答by Rodrigo Andrade
I know is a bit later to reply, sorry. But that works for me.
我知道有点晚才回复，抱歉。但这对我有用。
export K8S_public_load_balancer_url="$(kubectl get services -n ${TENANT}-production -o wide | grep "ingress-nginx-internal$" | awk '{print }')"
And now I am able to fetch and pass the content of the variable to jq
现在我可以获取变量的内容并将其传递给 jq
export TF_VAR_public_load_balancer_url="$(aws elbv2 describe-load-balancers --region eu-west-1 | jq -r '.LoadBalancers[] | select (.DNSName == "'$K8S_public_load_balancer_url'") | .LoadBalancerArn')"
In my case I needed to use double quote and quote to access the variable value.
在我的情况下，我需要使用双引号和引号来访问变量值。
Cheers.
干杯。
回答by DukeLion
Jq now have better way to acces environment variables, you can use env.EMAILI:
Jq 现在有更好的方法来访问环境变量，您可以使用 env.EMAILI：
projectID=$(cat file.json | jq -r ".resource[] | select(.username==env.EMAILID) | .id")
回答by markroxor
Little unrelated but I will still put it here, For other practical purposes shell variables can be used as -
一点不相关，但我仍然会把它放在这里，出于其他实际目的，shell 变量可以用作 -
value=10
jq '."key" = "'"$value"'"' file.json
