Store value to variable in Shell script

Question

"$emails" has the array of values, i want to parse the values from it, To do it, i am using the jq. if i do below command

echo "$emails" | ./jq '.total_rows'

i could get the value i.e 4, i want to store the returned results into some variable,

total_rows="$emails" | ./jq '.total_rows'

but total_rows has no value.

echo $total_rows

How do store the returned result into variable?

Nidhoegger · Accepted Answer · 2018-11-14T10:50:08.983

10

You have to use the right quotation, like this:

total_rows=`echo "$emails" | ./jq '.total_rows'`

The `` will execute the command and give total_rows the value of it, so whatever would be the output of

echo "$emails" | ./jq '.total_rows'

will so be stored in total_rows.

As mentioned in the comments by Tom Fenech, it is better to use $() for command substitution. It provides a better readability. So what you can do is:

total_rows=$(echo "$emails" | ./jq '.total_rows')

edited Nov 14 '18 at 10:50

answered May 29 '15 at 11:36

Nidhoegger

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Thanks @Nidhoegger. It works – Sivailango May 29 '15 at 11:41
3

I would recommend using `$( )` over backticks for command substitutions. Also, in bash you can use `total_rows=$(./jq '.total_rows' <<<"$emails")`. – Tom Fenech May 29 '15 at 11:44
Notice also you cannot add white space total_rows = ` doesn't work – Scott Warren May 19 '17 at 05:03

Store value to variable in Shell script

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