Linux Shells by Example

9.10. Processing Command Line Options with getopts

If you are writing scripts that require a number of command line options, positional parameters are not always the most efficient. For example, the Linux lscommand takes a number of command line options and arguments. (An option requires a leading dash; an argument does not. ) Options can be passed to the program in several ways: ls -laFi, ls -i -a -l -F, ls -ia -F, and so forth. If you have a script that requires arguments, positional parameters might be used to process the arguments individually, such as ls -l -i -F . Each dash option would be stored in $1, $2, and $3, respectively. But, what if the user listed all of the options as one dash option, as in ls -liF? Now the -liF would all be ...