Using Wildcard Characters in File Names

A single file name can specify many files using wildcard characters. The wildcard characters in make are ‘*’, ‘?’ and ‘[…]’, the same as in the Bourne shell. For example, *.c specifies a list of all the files (in the working directory) whose names end in ‘.c’.

The character ‘~’ at the beginning of a file name also has special significance. If alone, or followed by a slash, it represents your home directory. For example ~/bin expands to /home/you/bin. If the ‘~’ is followed by a word, the string represents the home directory of the user named by that word. For example ~john/bin expands to /home/john/bin. On systems which don’t have a home directory for each user (such as MS-DOS or MS-Windows), this functionality can be simulated by setting the environment variable HOME.

Wildcard expansion is performed by make automatically in targets and in prerequisites. In recipes, the shell is responsible for wildcard expansion. In other contexts, wildcard expansion happens only if you request it explicitly with the wildcard function.

The special significance of a wildcard character can be turned off by preceding it with a backslash. Thus, foo\*bar would refer to a specific file whose name consists of ‘foo’, an asterisk, and ‘bar’.

• Wildcard Examples		Several examples.
• Wildcard Pitfall		Problems to avoid.
• Wildcard Function		How to cause wildcard expansion where it does not normally take place.