Assign grep count to variable

Question

How to assign the result of

grep -c "some text" /tmp/somePath

into variable so I can echo it.

#!/bin/bash
some_var = grep -c "some text" /tmp/somePath
echo "var value is: ${some_var}"

I also tried:

some_var = 'grep -c \"some text\" /tmp/somePath'

But I keep getting: command not found.

Possible duplicate of [How to set a variable to the output of a command in Bash?](https://stackoverflow.com/questions/4651437/how-to-set-a-variable-to-the-output-of-a-command-in-bash) — codeforester, Oct 19 '18 at 23:40

that other guy · Accepted Answer · 2014-01-17T21:06:19.323

74

To assign the output of a command, use var=$(cmd) (as shellcheck automatically tells you if you paste your script there).

#!/bin/bash
some_var=$(grep -c "some text" /tmp/somePath)
echo "var value is: ${some_var}"

edited Jan 17 '14 at 21:06

answered May 01 '13 at 22:18

that other guy

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Thanks, for answer. But how to use input variable in executable part of code? my_var=$(grep "word" $1) - not works – Sonique Dec 03 '15 at 13:49

JavaSheriff · Answer 2 · 2013-05-01T22:31:13.773

36

Found the issue
Its the assignment, this will work:

some_var=$(command)

While this won't work:

some_var = $(command)

Thank you for your help! I will accept first helpful answer.

edited May 01 '13 at 22:31

answered May 01 '13 at 22:22

JavaSheriff

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Can't vote this up enough... These are the type of answers that make me grateful for SO. – Charlie Sep 10 '14 at 09:40
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Thanks a lot for this insight. Agree with Charlie. Can't vote this up enough. – ayan_2587 Jun 01 '15 at 08:21

Lev Levitsky · Answer 3 · 2013-05-01T22:21:01.550

3

some_var=$(grep -c "some text" /tmp/somePath)

From man bash:

   Command substitution allows the output of a command to replace the com‐
   mand name.  There are two forms:

          $(command)
   or
          `command`

   Bash performs the expansion by executing command and replacing the com‐
   mand substitution with the standard output of  the  command,  with  any
   trailing newlines deleted.

edited May 01 '13 at 22:21

answered May 01 '13 at 22:18

Lev Levitsky

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Variable assignments **cannot** have spaces around the `=`. – michaelb958--GoFundMonica May 01 '13 at 22:20
1

@michaelb958 You're right. My post was fixed before I noticed the problem. – Lev Levitsky May 01 '13 at 22:23
Lev this was the problem :) – JavaSheriff May 01 '13 at 22:31

Assign grep count to variable

3 Answers3

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