l i n u x - u s e r s - g r o u p - o f - d a v i s
L U G O D
 
Next Meeting:
August 5: Social gathering
Next Installfest:
TBD
Latest News:
Jul. 4: July, August and September: Security, Photography and Programming for Kids
Page last updated:
2001 Dec 30 17:08

The following is an archive of a post made to our 'vox-tech mailing list' by one of its subscribers.

Report this post as spam:

(Enter your email address)
Re: [vox-tech] Perl: Regex if then else
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [vox-tech] Perl: Regex if then else



On Tue, Aug 14, 2001 at 01:16:34PM -0500, Jay Strauss wrote:
> Unfortunately, I don't understand the error, or how to solve it
> 
> [jdedev]/home/jstrauss/bin> cat ./tmp
> #!/usr/bin/perl
> @s = ('initial 256','initial 512','initial 1024','initial 2048');
> 
> foreach (@s) {
>         s/(?<=initial\s+)(\d+)/$1 == 256 ? "4092" : "1024" /e;
>         print "$_\n";
> }
> 
> [jdedev]/home/jstrauss/bin> ./tmp
> Variable length lookbehind not implemented before HERE mark in regex
> m/(?<=initial\s+)(\d+) << HERE / at ./tmp line 14.

Hrm.  Sorry, my mistake.  Try this.

s/(initial\s+)(\d+)/ $1 . ($2 == 256 ? "4092" : "1024") /e;

The error meant that lookbehinds (the (?<=foo) thing) have to have a
constant length - no * or +.

Micah


LinkedIn
LUGOD Group on LinkedIn
Sign up for LUGOD event announcements
Your email address:
facebook
LUGOD Group on Facebook
'Like' LUGOD on Facebook:

Hosting provided by:
Sunset Systems
Sunset Systems offers preconfigured Linux systems, remote system administration and custom software development.

LUGOD: Linux Users' Group of Davis
PO Box 2082, Davis, CA 95617
Contact Us

LUGOD is a 501(c)7 non-profit organization
based in Davis, California
and serving the Sacramento area.
"Linux" is a trademark of Linus Torvalds.

Sponsored in part by:
Sunset Systems
Who graciously hosts our website & mailing lists!