replace an expression inside multiline string

[zcabeli]

Hi, i'd like to be able to search and replace a substring within a multiline string.

for example, if i've got the following text.

[code]
struct xyz {
unsigned x;
unsigned y;
unsigned z;
}

struct abc {
unsigned x;
unsigned y;
unsigned z;
}
[\CODE]

i'd like to replace only the 'x' variable within the 'xyz' struct and NOT within the 'abc' struct, to 'm' variable (just for the example). in order to achieve my goal, i need to use the non-greedy matching, so that i won't catch the 'x' variable within the 'abc' struct.

i've tried to use the /m modifier so that '.' will match also a newline character.

[code]
perl -p -e 's/(struct xyz.*)unsigned x/$1unsigned m/m' test
[\CODE]

unfortunately, this doesn't work. perhaps you can help me figure out my mistake

thanks,

[rovf]

How about non-greedy pattern matching? I.e. replace

.*

by

.*?

in your regexp.

[toolic]

This code does what you ask:

use warnings;
use strict;
use File::Slurp;
 
my $file = read_file('./test');
$file =~ s/(struct xyz.*?)unsigned x/$1unsigned m/s;
print "$file\n";

You need to use s///s and ? to prevent greediness.