Editing Shell script (section)

===Shortcuts===
A shell script can provide a convenient variation of a system command where special environment settings, command options, or post-processing apply automatically, but in a way that allows the new script to still act as a fully normal [[Unix command]].

One example would be to create a version of [[ls]], the command to list files, giving it a shorter command name of <code>l</code>, which would be normally saved in a user's <code>bin</code> directory as <code>/home/''username''/bin/l</code>, and a default set of command options pre-supplied.

<syntaxhighlight lang="sh">
#!/bin/sh
LC_COLLATE=C ls -FCas "$@"
</syntaxhighlight>

Here, the first line uses a [[#Configurable choice of scripting language|shebang]] to indicate which interpreter should execute the rest of the script, and the second line makes a listing with options for file format indicators, columns, all files (none omitted), and a size in blocks. The <code>LC_COLLATE=C</code> sets the default collation order to not fold upper and lower case together, not intermix [[dotfile]]s with normal filenames as a side effect of ignoring punctuation in the names (dotfiles are usually only shown if an option like <code>-a</code> is used), and the <code>"$@"</code> causes any parameters given to <code>l</code> to pass through as parameters to ls, so that all of the normal options and other [[programming language syntax|syntax]] known to ls can still be used.

The user could then simply use <code>l</code> for the most commonly used short listing.

Another example of a shell script that could be used as a shortcut would be to print a list of all the files and directories within a given directory.

<syntaxhighlight lang="sh">
#!/bin/sh

clear
ls -al
</syntaxhighlight>

In this case, the shell script would start with its normal starting line of <span style="font-family:courier">#!/bin/sh</span>. Following this, the script executes the command <span style="font-family:courier">clear</span> which clears the terminal of all text before going to the next line. The following line provides the main function of the script. The <span style="font-family:courier">ls -al</span> command lists the files and directories that are in the directory from which the script is being run. The <span style="font-family:courier">[[ls]]</span> command attributes could be changed to reflect the needs of the user.