Linux regex in substitution of a string passing argument from CLI

Asked Oct 02 '22 at 13:27

Active Oct 02 '22 at 13:27

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I have wrote the simple script

#!/bin/bash
progname=$1
sed -i.bak 's/#define SFFX ".*"/#define SFFX "$progname"/' path/to/file

In order to find a preprocessor directive in a C file and change it with bash. Problem is that the varibale identyfier $progname is not expanded, so that the substitution of the string #define SFFX "_foo" does not result in #define SFFX "_bar" when i run ./myscript.sh "bar".

How can one expand the varible i pass from command line into the regexp?

asked Oct 02 '22 at 13:27

opisthofulax

don't use single quotes if you want expansions to happen within the quotes, see What is the difference between the "...", '...', $'...', and $"..." quotes in the shell? and How to use a special character as a normal one in Unix shells? – ilkkachu Oct 02 '22 at 13:32
and maybe also What characters do I need to escape when using sed in a sh script? – ilkkachu Oct 02 '22 at 13:33

Linux regex in substitution of a string passing argument from CLI

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