in reply to This regular expression has me stumped

Not every problem is best solved with a big fat regex. 

while (my $line = <FILE>) {
    my @files = map { m!/([\w\.\-]+)\W*$!; $1 } 
                grep { m!/! } split ' ', $line;
    # blah

}

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The logic goes split on whitespace, ignore all tokens that don't have a file path sep / with , then get the last bit after the / up to the end or optional \W* using map. The character class [\w\.\-] should match most filenames. Normally I would use [^/] but this is problematic in this case. Should work on your data as described.

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Re^2: This regular expression has me stumped
by tsk1979 (Scribe) on May 01, 2008 at 09:08 UTC
    I was hung up on regexp because I want this via a command line perl -nei.bak..... I checked my log files /blah/blah/blah/filename can be follows by a whitespace, a "@' q "," or a ":" I have searched for perl non greedy and I suspect 
    /.*?[@:,\s+]/

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    will actually match the whole <code>/blah/blah/blah/filename.ext>/code> the problem here is, how to retain the filename...?
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[d/l]
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      You almost never want .* A negated character class is generally better. For example m!/[(^/)]+$! will grab the last bit of the filepath reliably but the regex posted above in the map should DWIM

      You could certainly code the example above as a one liner but it seems a waste of time to me. You can make a reusable 4 line script in less time than it will take fiddling. You can put options like -p -F -n on the shebang. As a one liner it would be like: 

      perl -F -ane 'print map{"$_\n"} map{ } grep { } @F' <file>

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      where the map and grep blocks are as above.

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[d/l]

      Picking up with the theme you were following, I got this to work. I haven't thought alot about corner cases, performance or reusability, so Grandfather's and tachyon-II's solutions are probably better.

      update: apparently I'm just confused on this matter && added comment on second s/// with no effect: I didn't like doing the substitution twice just to get the end-of-line anchor to work. Perhaps some wiser monks can explain that to me. update: That was before I added chomp, so never mind . . . 

      #/usr/bin/perl -W

$\="\n";

use strict;
use warnings;

while (<DATA>) {
    chomp;
    print $_;
    s/\/(?:[^\@:,\s+]*\/)(.*?)[\@:,\s+]*/\/new\/path\/$1/g;
    #s/\/(?:[^\@:,\s+]*\/)(.*?)[\@:,\s+]*$/\/new\/path\/$1/g;
    print $_;
    print '';
}


# produces:
# C:\chas_sandbox>
# 683879resp.pl
# file /user/name/some/path/to/filename@@ dumped: replaced /user/name/
+blah/blah/filename
# file /new/path/filename@@ dumped: replaced /new/path/filename
#
# @@@@user/some/file/filename.sdc: dumped
# @@@@user/new/path/filename.sdc: dumped

__DATA__
file /user/name/some/path/to/filename@@ dumped: replaced /user/name/bl
+ah/blah/filename
@@@@user/some/file/filename.sdc: dumped

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      #my sig used to say 'I humbly seek wisdom. '. Now it says:
      use strict;
      use warnings;
      I humbly seek wisdom.
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[d/l]
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A no-op in this map block: was Re^2: This regular expression has me stumped
by Narveson (Chaplain) on May 01, 2008 at 22:59 UTC

    No need for the; $1 in map { m!/([\w\.\-]+)\W*$!; $1 }

    since a match in list context returns the captured substrings and the block of a map is in list context.

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[d/l]
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      Good point. It was a rather off the cuff untested solution....

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