Posted by The TechMentor in BASH, Scripts
on Feb 13th, 2013
Sometimes we have a need to figure out which port, on a network switch, a given device is plugged into. In “Part 1” here we assume we have a single switch on our LAN. “Part 2” will go a little deeper and check multiple switches. Using this script, we can search by hostname, IP address, or MAC address. The MAC address is the key to success so, if searching by hostname or IP address, we need to first find the MAC address. We use the “arp” command to check our arp cache for the MAC address. To ensure the MAC address is in the arp cache, we first “ping” the...
Posted by The TechMentor in BASH, Scripts
on Dec 22nd, 2012
For today, a short little script to rename files that have capital letters in the name, to all lower case. Years ago this was a common need when copying files from a DOS based PC to a UNIX computer. That’s not so much an issue these days. However, it is a common problem when migrating a website from an IIS server, or an OS X server, to a Linux server, where case sensitivity all of a sudden becomes a concern. It skips any files that would overwrite any previously existing files. Really, nothing too fancy here… #!/bin/bash # Shell script to rename files, in the current directory, that...
Posted by The TechMentor in BASH, Scripts
on Dec 5th, 2012
Today’s dilema? I Revived an old script and pushed it out to a dozen or so different machines. Not really a big deal, except the script relies on the ‘uname’ command. Sadly, like many other commands, ‘uname’ isn’t always in the same place and I hate to rely on $PATH in scripts. Fortunately the solution is simple. I happen to know that it is likely in one of two places (though I check four). With this in mind a simple set of tests can get things running smoothly. #!/bin/bash if [ -x "/usr/local/bin/uname" ]; then uname="/usr/local/bin/uname"...
Posted by The TechMentor in Perl, Scripts
on Dec 3rd, 2012
Today I share a Perl snippet to iterate through log files in a specified directory. In this particular case there was a need to parse the log files, ignoring previously compressed files. The file names were in the format of: file.log file.log.1 file.log.2 file.log.3.gz file.log.4.gz … file.log.10.gz Though the file names could go up to *.99, we didn’t know which, if any, would be compressed. Obviously using “*.log” wouldn’t get the *.1 or *.2 files and using “*.log*” picked up the compressed files. The solution was to use “glob” with a couple...
