Bash functions, unlike functions in most programming languages do not allow you to return a value to the caller. When a bash function ends its return value is its status: zero for success, non-zero for failure. To return values, you can set a global variable with the result, or use command substitution, or you can pass in the name of a variable to use as the result variable.

Sometimes you need to add a new array on HP Servers on running system (you can't boot SmartStart DVD to run Array Configuration Utility). In that situation you need to configure the array with command line utility called hpacucli.

Previously I've shown how to use the bash while loop in a bash script. Today I'm going to show how to use another type of do loop in bash: the for loop.

Efforts to bring advanced typography to the web have reached an important milestone. Type designers Tal Leming and Erik van Blokland, who had been working to developing the .webfont format, combined forces with Mozilla's Jonathan Kew, who had been working independently on a similar format.

The devil they say is in details, even the simple Bash path variable can open some security problems on your box. Every Bash documentation out there warns us not leave '.' in the path (it matches current directory). They however don't seems to mention that leaving a dangling ':' (colon) at the beginning or the end of Bash $PATH does create the same security vulnerability.

You're most likely to have encountered the Perl @INC array in the context of a "cannot find module" error. This is the list of directories Perl searches when looking for a module. To see a list of what's in @INC, try this one-liner...

We often read (including in the book Advanced Bash-Scripting Guide by Mendel Cooper) that if we pass variable names as parameters to functions, they will be treated as string literals and cannot be dereferenced (ie the value is not available). But this is not so...

Let's say you have a directory with hundreds of files with the wrong file names, and you'd like to replace every filename containing test with prod. (this is a contrived example). We can easily do this with the "for" command in bash, combined with a little bit of bash goodness. Today we'll learn how to replace text in a variable in a for loop.

Type history at the Bash command prompt, and you'll get a list of your previous commands. You can navigate through these with the up and down arrows, but there are other ways of interacting with them that I've been investigating this week.