Just tried to replace a string called "test" by "replace" in a txt file

Your code looks for the string <text> (with angle brackets). What happens if you just use:

  $_ =~ s/test/replace/g;
[download]

If that doesn't work, try tips from the Basic debugging checklist: print and Data::Dumper.

Please edit your post and add code tags around your code: Writeup Formatting Tips