The second method is used when something is to be appended to the contents of the variable. This would do what its name implies, i.e. swap two files. But suppose we also wish to do error-checking, emitting an error message if the user gives fewer than two, or more than two, parameters. The commandlist is executed once for each word in the wordlist , and each time the variable var will contain the value of that word. The given string str is successively matched against the case patterns.
Control flow is switched to where the first match occurs.
The goto command provides a way to branch unconditionally to a line identified by a label. Set up a test directory, with several files in it, at least one of which is a subdirectory, with at least one file there. There are several books dealing with the C shell, but you should first read the man page for csh . You will find all kinds of features not mentioned here. This is standard notation in the software world, so remember it.