Perl Guru Forums: Perl Programming Help: Frequently Asked Questions: How do I use a regular expression to strip C style

CGI/Perl Guide | Learning Center | Forums | Advertise | Login

Site Search: in


	MAIN INDEX	SEARCH POSTS	WHO'S ONLINE	LOG IN

Home: Perl Programming Help: Frequently Asked Questions:
How do I use a regular expression to strip C style

Jasmine
Administrator

Mar 15, 2001, 6:02 AM

Post #1 of 1 (29053 views)

How do I use a regular expression to strip C style	Can't Post

How do I use a regular expression to strip C style comments from a file?

While this actually can be done, it's much harder than you'd think. For example, this one-liner

Code

    perl -0777 -pe 's{/\*.*?\*/}{}gs' foo.c

will work in many but not all cases. You see, it's too simple-minded for certain kinds of C programs, in particular, those with what appear to be comments in quoted strings. For that, you'd need something like this, created by Jeffrey Friedl:

Code

    $/ = undef; 
    $_ = <>; 
    s#/\*[^*]*\*+([^/*][^*]*\*+)*/|("(\\.|[^"\\])*"|'(\\.|[^'\\])*'|\n+|.[^/"'\\]*)#$2#g; 
    print;

This could, of course, be more legibly written with the /x modifier, adding whitespace and comments.

Search for (options)

Web Applications & Managed Hosting Powered by Gossamer Threads
Visit our Mailing List Archives