regex error

anaconda_wly has asked for the wisdom of the Perl Monks concerning the following question:

I got error in regex: Sequence \k... not terminated in regex; marked by <-- HERE in m/"c:\qa\k <-- HERE onductor\bin"/ at...

$binpath="c:\\qa\\kontor\\bin";
if( $ENV{PATH} !~ /$binpath/i) # error here
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It's OK when I type directly not using a string var.

if( $ENV{PATH} !~ /c:\\qa\\kontor\\bin/i)
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Anyone can point out my error?Thanks

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Re: regex error by aitap (Curate) on Apr 06, 2013 at 12:25 UTC
Use `/\Q$variable\E/` when you want to literally match the contents of a variable. More info is at the end of Quote and Quote like Operators, in quotemeta (as suggested above) and in Interpolation.	[reply] [d/l]
Re: regex error (backslashing) by LanX (Saint) on Apr 06, 2013 at 15:30 UTC
> It's OK when I type directly not using a string var. Different things! > `$binpath="c:\\qa\\kontor\\bin"` here you are backslashing to avoid string-interpolation within `"doublequotes"` > if( $ENV{PATH} !~ /c:\\qa\\kontor\\bin/i) here you are backslashing to avoid special escape `\commands` like `\k` So in your code you need 2 levels of escapes! `$binpath="c:\\\\qa\\\\kontor\\\\bin";` Do better combine `'singlequotes'` and quotemeta `\Q` and you avoid any explicit backslashing. Cheers Rolf ( addicted to the Perl Programming Language)	[reply] [d/l] [select]
Re^2: regex error (backslashing) by anaconda_wly (Scribe) on Apr 07, 2013 at 07:58 UTC
Thanks to all. I use index function also solve this issue.	[reply]
Re: regex error by Anonymous Monk on Apr 06, 2013 at 10:54 UTC
use quotemeta	[reply]
Re: regex error by igelkott (Priest) on Apr 06, 2013 at 15:11 UTC
As other have pointed out, you should generally use the correct type of quoting. But, if you're just using hard-coded paths, you can skip the fancy quotes if you switch to unix-style paths. In other words, change the assignment to `$binpath="c:/qa/kontor/bin";`. As mentioned in this very old post, paths are converted automatically. Personally, I prefer this method so I can use the same script on PC and Linux. Well, at least for relative directories.	[reply] [d/l]