5 Bash for loop examples to make command line tasks more efficient

One of the things that excited me while learning Unix/Linux was how quickly one can perform tasks via the command line. Bash is a fully functional scripting language that incorporates Variables, Loops and If/Then statements; the bash shell allows a user to use these functions while performing adhoc tasks via the command line. This is also true for the other common shells such as bourne, korn shell, and csh. Below I will show 5 example for loops that are run on the command line without being placed into a shell script....

 · 6 min · Benjamin Cane

Setting process CPU priority with nice and renice

Nice is a command in Unix and Linux operating systems that allows for the adjustment of the “Niceness” value of processes. Adjusting the “niceness” value of processes allows for setting an advised CPU priority that the kernel's scheduler will use to determine which processes get more or less CPU time. In Linux this niceness value can be ignored by the scheduler, however other Unix implementations can treat this differently. Being able to adjust the niceness value comes in handy in two scenarios usually....

 · 4 min · Benjamin Cane

Grepping a file without using cat, and other grep tricks

The grep command is a command that most Linux users learn early on, and many times they learn to use it via pipes (stdin). Because of this some Linux users just assume that grep can only be used with stdin; it's ok, I was one of those too! Before I continue with some grep tricks I want to clarify the basic grep usage. Stop Doing This: $ cat file.log | grep "something" something Do This More:...

 · 3 min · Benjamin Cane

Packing and Unpacking files with GNU Tar

One of the most basic tasks for any Sysadmin is packing and unpacking files for various reasons. While there are many ways to perform this task GNU Tar is probably one of the most recognized and commonly used tools by Linux/Unix users. A little history on tar The tar command is a command that appeared in the early days of Unix and has had several changes made over time. Originally the command was used to take files, combine them into one file and write them to a tape archive (tar)....

 · 7 min · Benjamin Cane

Removing Files and Directories with rm and rmdir

Normally on this blog I tend to write about more complicated tasks or fancy Linux tricks and completely overlook some of the most basic tasks that a SysAdmin needs to know. Today I have decided that I will make my blog a little more comprehensive and add some posts with some of the basics. Along with this I will be starting a new category, called Sysadmin Basics and I will try to post an additional article each week that covers some of the more basic concepts and commands used by Linux and Unix Sysadmins....

 · 4 min · Benjamin Cane