How to use a Bash Shell script to record the activity of users. This
script is useful in rebuilding the actions of users as they work at
the command line.

Command substitution takes the output of one Linux command and makes it an argument in another command.

The Bash shell provides a builtin command that allows you to test the exit status of a command to determine if the command was successful or not. The test command provides a way to make decisions about what will happen next in a script.

Say you want to write a small shell script that locks up your GNOME desktop at specific intervals. What command would you use? In this case, your best bet would be gnome-screensaver-command –lock This has the same effect as you pushing the Lock Screen button in GNOME. You can forge a small shellscript and use this to lock up your desktop when someone launches an application.

Reading files is no big deal with bash: you just redirect the input to the script or pipe the output of another command into the script, or you could do it inside the script if the file names are pre-determined. You could also use process substitution to pass in the open files (command pipelines actually) from the command line.

I've shown previously how to use the more command to view text output. Today I'll show how to do the same thing with the less command. You can run the command simply by opening a terminal window and entering...

The first time I played with Zenity, I recognized several potential uses for it. While I'm pretty comfortable with interacting with computers with a command line interface, I know many people are not. Zenity creates GUI widgets from a simple command line and can be used from any shell script.

GNU Screen is one of the most useful utilities you can have at your disposal if you spend any time at all working at the command line. Screen allows you to manage multiple shell sessions from one terminal window or console, view multiple shell sessions at the same time, and even log into the same session from more than one location at a time.

Working on a little script the other day I had the need to determine if the input to the script was coming from a pipe or from the terminal. Seems like a simple enough thing to determine but nothing jumped immediately to mind and a quick internet search didn't help much either. After a bit of pondering I came up with two solutions: the stat command and using information from the proc file system.