This is a small thing; I had something unexpected happen. I assumed (always a problem) that single-quoted strings didn't interpolate. Ever. In the following situation, I seem to need an escape-character to keep it from interpolating. If it's not interpolating, why do I need the double-backslash?

This is what fails:

#/usr/bin/perl -lW

use strict;
use warnings;
$\="\n";

my $path = 'C:\chas_sandbox\';

my $otherstring = '//Project/State/Task/Server';


print '$path: '.$path;
print '$otherstring: '.$otherstring;

[download]
producing: 
C:\chas_sandbox>
singlequoteinterp.pl
Bareword found where operator expected at C:\chas_sandbox\singlequotei
+nterp.pl l
ine 9, near "/Project/State"
        (Missing operator before State?)
syntax error at C:\chas_sandbox\singlequoteinterp.pl line 9, near "/Pr
+oject/Stat
e"
Bad name after Server' at C:\chas_sandbox\singlequoteinterp.pl line 9.

[download]

It seems to think $path starts with 'C:\ and extends all the way down to the singlequote in my $otherstring = '. The single quote in the middle is escaped by the backslash. It accepts //Project/ as some sort of search and replace regexp on the implied $_, and is confused by State all by itself after that.

This works:

#/usr/bin/perl -lW

use strict;
use warnings;
$\="\n";

my $path = 'C:\chas_sandbox\\';

my $otherstring = '//Project/State/Task/Server';


print '$path: '.$path;
print '$otherstring: '.$otherstring;

[download]
producing:
C:\chas_sandbox>
singlequoteinterp.pl
$path: C:\chas_sandbox\
$otherstring: //Project/State/Task/Server

[download]

I need to escape the backslash so that it doesn't escape the single quote. If it's not interpolating, why do I need to escape anything?

I'm on WindowsXP / Strawberry Perl 5.8:

C:\chas_sandbox>
perl -v

This is perl, v5.8.8 built for MSWin32-x86-multi-thread

Copyright 1987-2006, Larry Wall

Perl may be copied only under the terms of either the Artistic License
+ or the
GNU General Public License, which may be found in the Perl 5 source ki
+t.

Complete documentation for Perl, including FAQ lists, should be found 
+on
this system using "man perl" or "perldoc perl".  If you have access to
+ the
Internet, point your browser at http://www.perl.org/, the Perl Home Pa
+ge.

[download]

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

In reply to Interpolation in Single-quotes? by goibhniu

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