[Linux] How to escape single quote in 'sh -c'

Sometimes, you need to run a command in ‘sh -c’ and to avoid its subshell expression is evaluated in parent shell, you need to put the command string into a single quote, like:

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sh -c 'a="hello world"; echo $a'

However, for some commands in the command string, you need to use single quote such as awk, and how do you escape the single quote in the command string?

If you use a backslash to escape the single quote as we do normally in bash, it will look like this:

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sh -c 'a="hello world"; echo $a | awk \'{print $2}\' '

It will not work, and show errors like:

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awk: cmd. line:1: {print
awk: cmd. line:1:       ^ unexpected newline or end of string

The correct way to escape the single quote in the command string is to use 3 single quotes, like this:

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sh -c 'a="hello world"; echo $a | awk '\''{print $2}'\'''

This will work as expected and print world.

So that’s it. Use '\'' to escape a single quote in the command string of sh -c.

Happy Programming. 😃

Last modified on 2025-05-04