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

[download]

#my sig used to say 'I humbly seek wisdom. '. Now it says:
use strict;
use warnings;
I humbly seek wisdom.

In reply to Re^3: This regular expression has me stumped by goibhniu
in thread This regular expression has me stumped by tsk1979

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.