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.|