File name substitution is a feature which allows strings to be substituted for patterns and special characters. This provides greater flexibility and saves a lot of typing time. Most frequently this feature is used to match file names in the current directory, but can also be used to match arguments in case and [[...]] commands.
The syntax for file name substitution is not the same as regular expression syntax used in some Unix commands like ed, grep, and sed. The examples in the following sections assume that the following files exist in the current directory:
$ ls —a . .molog abc dabkup3 mobkup1 .. a dabkup1 dabkup4 mobkup2 .dalog ab dabkup2 dabkup5
The * character matches any zero or more characters. ...