Another strategy would be to simply do the subtitution on a substring that leaves out the first and last char: 
substr($t, 1, -1) =~ s/"/""/g;

[download]
This however seems to be slower, according to a quick benchmark I've run (zwa = 'zero-width assertion', sub = 'substr'): 
Benchmark: timing 1048576 iterations of sub, zwa...
       sub: 16 wallclock secs (15.07 usr +  0.00 sys = 15.07 CPU) @ 69
+580.36/s
       zwa: 13 wallclock secs (12.58 usr +  0.00 sys = 12.58 CPU) @ 83
+352.62/s
       Rate  sub  zwa
sub 69580/s   -- -17%
zwa 83353/s  20%   --

[download]
But it is perhaps easier to understand (which would make it a better choice if the speed difference isn't relevant)

•Update: ran the benchmark again, this time without other processes eating up wallclock secs; to avoid confusion

•Update: I'm enclosing my (fairly pointless) benchmark stuff in readmore-tags to avoid cluttering the thread

In reply to Re: Regex matching on anywhere but the beginning or end of a line by xmath
in thread Regex matching on anywhere but the beginning or end of a line by Anonymous Monk

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