POSIX character classes
Class |
Description |
---|---|
[:alnum:] |
Letters and numbers, as in [a-zA-Z0-9] |
[:alpha:] |
Letters, as in [a-zA-Z] |
[:blank:] |
Blanks |
[:cntrl:] |
Controls |
[:digit:] |
Numbers, as in [0-9] |
[:graph:] |
Printable characters (blanks excluded) |
[:lower:] |
Small letters, as in [a-z] |
[:print:] |
Characters which are not controls |
[:punct:] |
Punctuations |
[:space:] |
Spaces |
[:upper:] |
Capital letters, as in [A-Z] |
[:xdigit:] |
Characters used to express a hexadecimal number, as in [0-9a-fA-F] |