Replace only first match in multiple files with perl

Question

I need to replace a bit of text in multiple css files, but ony the first occurence.

I've tried replacing with:

perl -pi -e 's/(width:).*;/$1 100%;/' filename.css

But this replaces the value after every occurrence of 'width:' in the file, even though i'm not using the /g modifier. I'm running this on a recent Ubuntu machine.

Answer 1

You can stop the replacement after the first one:

perl -pi -e '$a=1 if(!$a && s/(width:).*;/$1 100%;/);' filename.css

Answer 2

Nobody has addressed an implication of your actual title question. I recommend the same approach as used here, only modified:

perl -pie '!$subbed{$ARGV} and s/(width:).*;/$1 100%;/ and $subbed{$ARGV}++' *.css

The un-dimensioned $ARGV is the name of the current file. So for each file, you're replacing only the first occurrence. The "glob" *.css will send multiple files. If you do the scalar switch that other people are suggesting, you will modify only the first occurrence in the first file with that pattern. (Though, perhaps that is what you want.)

Answer 3

If you read in paragraph mode, each file is only one line; hence the s/// without the /g modifier will replace the first instance in each file, then move to the next file:

perl -0777 -pi -e's/(width:).*;/$1 100%;/' *.css