Character classes
You can use character classes to match file names.
You can use character classes to match file names, as follows:
[[:charclass:]]This format instructs the system to match any single character belonging to the specified class. The defined classes correspond to ctype subroutines, as follows:
| Character Class | Definition |
|---|---|
| alnum | Alphanumeric characters |
| alpha | Uppercase and lowercase letters |
| blank | Space or horizontal tab |
| cntrl | Control characters |
| digit | Digits |
| graph | Graphic characters |
| lower | Lowercase letters |
| Printable characters | |
| punct | Punctuation characters |
| space | Space, horizontal tab, carriage return, newline, vertical tab, or form-feed character |
| upper | Uppercase characters |
| xdigit | Hexadecimal digits |