Perl Tipps und Tricks

Tipps und Tricks

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

Usage of perl as a spcial grep :-): <syntaxhighlight lang=bash> perl -ne 'if (/(<a href=[^>]+action=login[^>]+>(?:(?!<\/a>).)*<\/a>)/){ print $1."\n"; }' index.html </source>

This one matches a complete

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

.

Or more complex: <syntaxhighlight lang=bash> perl -ne 'if (/(<a href=[^h]*(http[s]{0,1}:\/\/([^\/"]+)[^> "]+)[^> ]*>(?:(?!<\/a>).)*<\/a>)/){ print $3."|".$2."|".$1."\n"; }' index.html </source>

Prints out:

<server>|<url>|<complete href>

Unread while reading from filehandle

Dov Grobgeld made my day!

<syntaxhighlight lang=perl>

1. 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

} </source>

Config

Override compile time flags on the commandline like this: <syntaxhighlight lang=perl> PERL_MM_OPT='optimize=-O2 cc=gcc ld=gcc cccdlflags=-DPIC' </source>

I used it to run sa-compile on Solaris: <syntaxhighlight lang=perl>

1. !/bin/bash

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

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` </source>