http://www.celsobarriga.com Wasting bandwidth in style! Mon, 28 Jul 2008 06:21:25 +0000 http://backend.userland.com/rss092 en Here's how to determine the dates when the Daylight Savings Time changes for a given year (I keep forgetting how to do this.): zdump -v /etc/localtime|grep 2008 /etc/localtime Sun Mar 9 06:59:59 2008 UTC = Sun Mar 9 01:59:59 2008 EST isdst=0 gmtoff=-18000 /etc/localtime Sun Mar ... http://www.celsobarriga.com/2008/02/01/how-to-determine-dst-time-changes/ Here's how to cleanly uninstall any Perl module: #!/usr/local/bin/perl use ExtUtils::Packlist; use ExtUtils::Installed; $ARGV[0] or die "Usage: $0 Module::Name\n"; my $mod = $ARGV[0]; my $inst = ExtUtils::Installed->new(); foreach my $item (sort($inst->files($mod))) { print "removing $item\n"; unlink $item; } my $packfile = $inst->packlist($mod)->packlist_file(); print "removing ... http://www.celsobarriga.com/2008/01/10/uninstall-perl-module/ I found this command useful in finding out which top 10 processes are hogging my CPU resources. Note that this command is specific to the Red Hat flavor of Linux. See the man page for ps for the correct output format to use for your specific platform: ps -eo pcpu,pid,user,args | ... http://www.celsobarriga.com/2007/08/29/find-out-the-top-10-cpu-hogs/ Here's another logging routine, this one is written in Bourne shell: #!/bin/sh log_message() { echo `date "+%m/%d/%y %H:%M:%S %Z"` "$1" | tee -a aaa.out } log_message "Hello there" log_message "Goodbye" Sample output: 08/28/07 23:16:13 EDT Hello there 08/28/07 23:16:13 EDT Goodbye http://www.celsobarriga.com/2007/08/28/bourne-shell-logging-routine/ To set up root password the first time: $ mysqladmin -u root password NeWPasSwORd To change an existing root password: $ mysqladmin -u root -p oldpassword newpass Enter password: To change a normal user password: $ mysqladmin -u dbuser-p oldpassword newpass http://www.celsobarriga.com/2006/08/23/setting-mysql-password/ The following will sort an array of IP addresses in @in and the sorted IP addresses will be in @out. @out = sort { pack('C4' => $a =~ /(\d+)\.(\d+)\.(\d+)\.(\d+)/) cmp pack('C4' => $b =~ /(\d+)\.(\d+)\.(\d+)\.(\d+)/) } @in; What this does is it forms a ... http://www.celsobarriga.com/2006/07/13/sorting-ip-addresses/ Here's how to find out your external IP address courtesy of this hint: http://www.macosxhints.com/article.php?story=20060602180942480 curl --silent http://checkip.dyndns.org | awk '{print $6}' | cut -f 1 -d " http://www.celsobarriga.com/2006/06/07/find-external-ip-address/ The code below is a template for a daemon written in Perl. Use the code below as a starting point when you have to write a program that has to persist in the background to do its things and without a gui. use POSIX qw(setsid); chdir '/' or die "Can't chdir to ... http://www.celsobarriga.com/2006/05/24/write-a-daemon-in-perl/ Line terminations for different operating systems: unix0x0aLF Classic Mac0x0dCR Windows0x0d 0x0aCR LF To convert a text file with DOS line termination to UNIX line termination: tr -d '\015' < winfile.txt > unixfile.txt or sed s/.$// winfile.txt > unixfile.txt To convert a unix file to a DOS file: sed s/$/\x0d/ unixfile.txt > winfile.txt http://www.celsobarriga.com/2006/04/13/line-terminations/ Mac OS X has to run some maintenance scripts in the middle of the night to do some important housekeeping tasks. If you have a Mac that sleeps in the middle of the night, as you do, you need to run these manually by running this from the shell: sudo periodic ... http://www.celsobarriga.com/2006/02/11/run-periodic-maintenance-scripts-manually/