Linux Shells by Example

1.6. Executing Commands from Scripts

When the shell is used as a programming language, commands and shell control constructs are typed in an editor into a file, called a script. The lines from the file are read and executed one at a time by the shell. These programs are interpreted, not compiled. Compiled programs must convert the program into machine language for it to be executed. Therefore, shell programs are usually slower than binary executables, but they are easier to write and are used mainly for automating simple tasks. Shell programs can also be written interactively at the command line, and for very simple tasks, this is the quickest way. However, for more complex scripting, it is easier to write scripts in an editor (unless you are ...