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:
January 6: Social gathering
Next Installfest:
TBD
Latest News:
Nov. 18: Club officer elections
Page last updated:
2002 Jan 12 19:00

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] dumb perl question
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [vox-tech] dumb perl question




--- Peter Jay Salzman <p@dirac.org> wrote:
> the string that i'm matching though is $_, not
> $temperature.  $_ holds a
> filename, like "100.energy", and i'd like to extract
> the "100" from the
> filename and put it in $temperature.
> 
> doesn't
> 
> 	$temperature =~ s/(\d+).*/$1/;
> 
> assume that $temperature is the object holding
> "100.energy"?

Yes it does.

> 
> note that i'm being greedy here -- this DOES work:
> 
> 	/(\d+).*/;              # match "100" in $_
> 	$temperature = $+;      # put it in $temperature
> 
> i just want to do it in a single line.  :)   also,
> i'd like to do it
> without destroying the contents of $_ if possible.

Then your approach is the only way I know.  But, you
may want to take care of 'no match' cases.  $+ is the
last match.  If your match fails, then a prior match
will be picked up, *I think*.  (Not tested.)

One other point. the '.' is a metacharacter that
matches anything except a newline character.  So .*
matches the rest of the line.  It you want to match a
'.' then escape it:

# -----
use strict;
$_ = '100.energy';

/^(\d*)\./;
print "temp: $1\n";
# -----

Good luck.
Jim



__________________________________________________
Do You Yahoo!?
Send FREE video emails in Yahoo! Mail!
http://promo.yahoo.com/videomail/
_______________________________________________
vox-tech mailing list
vox-tech@lists.lugod.org
http://lists.lugod.org/mailman/listinfo/vox-tech



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:
EDGE Tech Corp.
For donating some give-aways for our meetings.