Perl – Fork and Kill a System Process on Timeout [perl] $pid = open(PIPE, “$command |”) or die $!; eval { local $SIG{ALRM} = sub { die “TIMEOUT” }; alarm($timeout); while (<PIPE>) { $data = $_; }; close(PIPE); alarm(0); }; if ($@) { die $@ unless $@ =~ /TIMEOUT/; kill 15, $pid; close(PIPE); $? ||= […]
Amazon – Ubuntu CPAN Perl Install If you experiencing any issues with installing, upgrading or managing CPAN perl libraries on a refreshley deployed Amazon EC2 instance make sure you have your build essentials!! Run: sudo apt-get install build-essential
Get Parent PID [perl] my $parent_id = getppid(); print “$parent_id\n”; [/perl] NAME getppid – get parent process ID SYNOPSIS getppid DESCRIPTION Returns the process id of the parent process. DISCLAIMER We are painfully aware that these documents may contain incorrect links and misformatted HTML. Such bugs lie in the automatic translation process that automatically created […]
Get PID (process id) from Perl Script $$ or $PID
Perl – Lock Files (flock) The following script is an example of using lock files in Perl. This prevents more than one user or process accessing a file at a time. [perl] use Fcntl qw(:DEFAULT :flock); use Fcntl ‘:flock’;¬†¬†¬†¬† #LOCK_* constants my($lockneedsremoving)=0; my($lockfilename)=”/var/.pwd.lock”; unless (createlock()) { print “Lock has been created”; print “This is only […]
Perl Substr substr This function supports three sets of passed values as follows: [perl] substr (STRING,OFFSET,LEN,REPLACEMENT) substr (STRING,OFFSET,LEN) substr (STRING,OFFSET) [/perl] The function: substr (STRING,OFFSET) returns all characters in the string after the designated offset from the start of the passed string. The function: substr (STRING,OFFSET,LEN) returns all characters in the string after the designated […]
Perl Lower/Upper Case First Character ucfirst Takes a string and retruns it with the first character in upper case. [perl] ucfirst Str1 [/perl] lcfirst Takes a string and retruns it with the first character in lower case. [perl] lcfirst Str1 [/perl]
Perl Upper Case uc Converts all characters in the string to upper case. [perl] uc Str [/perl]
Perl Index index This function returns the position of the first occurance of the specified SEARCH string. If POSITION is specified, the occurance at or after the position is returned. The value -1 is returned if the SEARCH string is not found. [perl] rindex STRING,SEARCH,POSITION rindex STRING,SEARCH [/perl]
Perl Lower Case lc Converts all characters in the string to lower case. [perl] lc Str [/perl]