10 Pattern Matching

The GNU C Library provides pattern matching facilities for two kinds of patterns: regular expressions and file-name wildcards. The library also provides a facility for expanding variable and command references and parsing text into words in the way the shell does.

• Wildcard Matching: Matching a wildcard pattern against a single string.
• Globbing: Finding the files that match a wildcard pattern.
• Regular Expressions: Matching regular expressions against strings.
• Word Expansion: Expanding shell variables, nested commands, arithmetic, and wildcards. This is what the shell does with shell commands.