A chronological documentation test project, nothing serious, really!
Using select to make simple menus #!/bin/bash OPTIONS=”Hello Quit” select opt in $OPTIONS; do if [ “$opt” = “Quit” ]; then echo done exit elif [ “$opt” = “Hello” ]; then echo Hello World else clear echo bad option fi done If you run this script you’ll see that it is a programmer’s dream for […]
As in almost any programming language, you can use functions to group pieces of code in a more logical way or practice the divine art of recursion. Declaring a function is just a matter of writing function my_func { my_code }. Calling a function is just like calling another program, you just write its name. […]
The for loop is a little bit different from other programming languages. Basically, it let’s you iterate over a series of ‘words’ within a string. The while executes a piece of code if the control expression is true, and only stops when it is false (or a explicit break is found within the executed code. […]
Theory and quick reference There are 3 file descriptors, stdin, stdout and stderr (std=standard). Basically you can: redirect stdout to a file redirect stderr to a file redirect stdout to a stderr redirect stderr to a stdout redirect stderr and stdout to a file redirect stderr and stdout to stdout redirect stderr and stdout to […]
Everyone has done one of the following to make a quick backup of a file: $ cp filename filename-old $ cp filename-old filename These seem fairly straightforward, what could possibly make them more efficient? Let’s look at an example $ cp filename{,-old} $ cp filename{-old,} $ cp filename{-v1,-v2} Brace expansion can take place anywhere in […]