Sandra Henry-Stocker
Unix Dweeb
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Sandra Henry-Stocker has been administering Unix systems for more than 30 years. She describes herself as "USL" (Unix as a second language) but remembers enough English to write books and buy groceries. She lives in the mountains in Virginia where, when not working with or writing about Unix, she's chasing the bears away from her bird feeders.
The opinions expressed in this blog are those of Sandra Henry-Stocker and do not necessarily represent those of IDG Communications, Inc., its parent, subsidiary or affiliated companies.
Ways to look at logged in users on Linux
Linux provides a lot of useful commands for looking at users, their activity and their impact on the system.
Looking at user login time with the ac command
The ac command can provide very useful summaries of how much time users spend logged into a Linux system. It gets its data from the wtmp file.
Bash: A primer for more effective use of the Linux bash shell
There are lots of sides to bash and much to know before you're likely to feel comfortable snuggling up to it. This post examines many aspects of this very popular shell and recommends further reading.
Counting individual characters on Linux
If you need to count how many of each character is included in a file or phrase, there are some handy commands you can string together to accomplish this along with scripts and aliases that can make the job easy.
Finding and fixing typos on Linux
The Linux aspell and enchant tools can both ID typos in text files and suggest replacements.
Using Wikipedia from the Linux command line
A tool called wikit provides an easy way to get information from Wikipedia without leaving the Linux command line.
Using functions in bash to selectively run a group of Linux commands
Bash functions can group related commands in Linux and run them as frequently or infrequently as needed. They can also make scripts more readable by organizing commands by the roles they play.
Using bash options to change the behavior of scripts
Here are some of the more popular bash options to control how scripts work on Linux and how to list the available options, including seeing which ones are turned on.
Using 'break' and 'continue' to exit loops in bash
As nice as looping in Linux scripts can be, you might just want to interrupt it sometimes, and the break and continue commands can do this.
Using the Linux apropos command – even if you have to fix it first
The apropos command can help you find commands or discover some you don't yet know, but if you get the response "nothing appropriate", it might need some help.
How to work on Linux with filenames that contain blanks
Filenames that contain blanks can add complexity to the commands you use to work with them. Fortunately, there are several handy ways to make that easier.