Regular expression substitution with whitespace (perl)

Question

I would like to replace all matches of the following perl regular experssion

s@typedef\s*([\w\s<>,:]*)\s(\w+)\s*;@using \2= \1;@g

in a file.

I have done this with :

/usr/bin/perl -p -i -e "s@typedef\s*([\w\s<>,:]*)\s(\w+)\s*;@using \2= \1;@g"  ./file.txt

The problem, the substituion does not work as long as I leave the whitespaces in "using \\2= \\1" ? how can I make this work?

ERROR: Substitution replacement not terminated at -e line 1.

Answer 1

The shell in which you're invoking your perl command is doing substitution on the regular expression that you're passing in.

Use

/usr/bin/perl -p -i -e 's@typedef\s*([\w\s<>,:]*)\s(\w+)\s*;@using \2= \1;@g'  ./file.txt

instead.

The difference here is that the regex is in single quotes. This prevents shell substitution.