Perl Tipps und Tricks

Tipps und Tricks

Negative match in RegEx (?:(?!PATTERN).)*

Usage of perl as a spcial grep :-):

perl -ne 'if (/(<a href=[^>]+action=login[^>]+>(?:(?!<\/a>).)*<\/a>)/){ print $1."\n"; }' index.html

This one matches a complete

<a href=...action=login...>(not </a>)</a>

.

Unread while reading from filehandle

Dov Grobgeld made my day!

# Found at a comment of Dov Grobgeld at https://groups.google.com/d/msg/comp.lang.perl/7fPyGpWpP8M/hc7xTMvAoW0J
while($_ = shift(@linestack) || <IN>) {
         :
             push(@linestack, $whatever);   # unread
}

Config

Override compile time flags on the commandline like this:

PERL_MM_OPT='optimize=-O2 cc=gcc ld=gcc cccdlflags=-DPIC'

I used it to run sa-compile on Solaris:

#!/bin/bash

exec >> /var/log/update-spamd-rules.log 2>&1

#LD_LIBRARY_PATH=/usr/sfw/lib 
PATH=$PATH:/usr/local/bin:/opt/re2c/bin:/usr/sfw/bin:/usr/ccs/bin:/opt/csw/bin

PERL_VER=$(/usr/perl5/bin/perl -e 'printf "%.3f",$];')
SA_VER=$(/opt/spamassassin/bin/spamassassin -V | /usr/bin/nawk '
/SpamAssassin version/ {
  split($NF,version,/\./);
  printf "%d.%03d%03d",version[1],version[2],version[3];
}')

export LD_LIBRARY_PATH PATH PERL_VER SA_VER

/usr/perl5/bin/perlgcc -T /opt/spamassassin/bin/sa-update --updatedir=/var/opt/spamassassin/$SA_VER -D
PERL_MM_OPT='optimize=-O2 cc=gcc ld=gcc cccdlflags=-DPIC' /opt/spamassassin/bin/sa-compile  --updatedir=/var/opt/spamassassin/compiled/${PERL_VER}/${SA_VER} -D 

/usr/bin/kill -HUP `cat /tmp/spamd-exim-acl.pid`
/usr/bin/kill -HUP `cat /tmp/spamd-ip.pid`