About Special Parameters Special parameters are set by the shell to store information about aspects of its current state Example 1: the number of arguments of the current script Example 2: the exit code of the last command. Their names are nonalphanumeric characters (for example, *, #, and _). Variables are identified …

About Parameters in bash A parameter is an entity that stores values. There are three types of parameters: positional parameters special parameters variables We'll discuss here only positional parameters. (the other types will be discussed in other posts) Positional Parameters These are arguments present you give a …

Shell Script A shell script is a file containing one or more commands You could type those commands individually on the command line Here's the content of my first shell script: 1echo Hello World! We have already encountered the [echo] command in Command Types Now I have to give my file a name: do not choose a name …

UNIX philosophy Every operating system needs to interract with users. The original UNIX philosophy said (among other things): Write programs that do one thing and do it well. Write programs to work together. This philosophy applis also to the interraction with the user, and the kernel. In other words, the UNIX system …