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

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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

    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:

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

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


Source: Perl FAQ: Regexps
Copyright: Copyright (c) 1997 Tom Christiansen and Nathan Torkington.
Next: Can I use Perl regular expressions to match balanced text?

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