I have been using this script to check for updates on my Redhat systems for quite some time. Put this into your cron.daily, and you have a daily nag to update your system.

#!/bin/bash                                                                                       

#########
## Yum Check Update Script
##
## This script checks for system updates and sends email
## to sysmin team if there are any updates.
##
## Changelog
## ---------
## 24 Oct 2008 (Junhao)
## - Initial commit
##
#########

_CAT="/bin/cat"
_DATE="/bin/date"
_HOSTNAME="/bin/hostname"

Here's another script I did when I had to reorganised a folder hierarchy of years of data. Basically to ensure files are not missing, or corrupted.

#!/bin/bash                                                                                                                              

#########################
#                        
# checkNoMissingFiles    
# ===================    
#                        
# This script checks that no files are missing after folders are reorganised.
# Basic algorithm is to checksum all files in both old and new folders, then 
# checking through both lists of checksums to ensure all checksums are present
# in both lists.

I am currently migrating out of Zimbra to a 3rd-party host. Just for archival, here's my Zimbra backup script. Just run this script using a cronjob every day. There will be a short downtime where Zimbra is shutdown to synchronise the last bit of emails, but that should be okay if you have a backup MX server.

This script creates a working live copy of the Zimbra directory, then shutdown Zimbra to sync the directory. The directory is then passed through star, into a small(er) file.

I went looking around for bash scripting tips, especially secure coding of bash. Can't find much information, so decided to consolidate whatever I found here.

• Salt string comparisons of variables to increase security
  

  if [[ "a$?" == "a4" ]]; then
  

*Updated: 11 Dec 2007

I'm wondering where I should store the scripts I'm writing. Out of pure laziness, I'll just dump them as my blog entry for now.

Here's a script to check for missing files after a directory has been re-organised. Basically, it compares the md5sum of the files in the old directory and the new directory.

Please let me know if there are any bugs.

#!/bin/bash

#########################
#
# checkNoMissingFiles
# ===================
#
# This script checks that no files are missing after folders are reorganised.