| POSIX | Description | ASCII | Unicode | Shorthand | Java |
|---|---|---|---|---|---|
| [:alnum:] | Alphanumeric characters | [a–zA–Z0–9] |
[\p{L}\p{Nl} \p{Nd}] |
\p{Alnum} | |
| [:alpha:] | Alphabetic characters | [a–zA–Z] | \p{L}\p{Nl} | \p{Alpha} | |
| [:ascii:] | ASCII characters | [\x00–\x7F] | \p{InBasicLatin} | \p{ASCII} | |
| [:blank:] | Space and tab | [ \t] | [\p{Zs}\t] | \h | \p{Blank} |
| [:cntrl:] | Control characters | [\x00–\x1F\x7F] | \p{Cc} | \p{Cntrl} | |
| [:digit:] | Digits | [0–9] | \p{Nd} | \d | \p{Digit} |
| [:graph:] | Visible characters (anything except spaces and control characters) | [\x21–\x7E] | [^\p{Z}\p{C}] | \p{Graph} | |
| [:lower:] | Lowercase letters | [a–z] | \p{Ll} | \l | \p{Lower} |
| [:print:] | Visible characters and spaces (anything except control characters) | [\x20–\x7E] | \P{C} | \p{Print} | |
| [:punct:] | Punctuation and symbols. |
[!”\#$%&'()*+, \-./:;<=>?@\[ \\\]^_`{|}~] |
\p{P} | \p{Punct} | |
| [:space:] | All whitespace characters, including line breaks | [ \t\r\n\v\f] | [\p{Z}\t\r\n\v\f] | \s | \p{Space} |
| [:upper:] | Uppercase letters | [A–Z] | \p{Lu} | \u | \p{Upper} |
| [:word:] | Word characters (letters, numbers and underscores) | [A–Za–z0–9_] |
[\p{L}\p{Nl} \p{Nd}\p{Pc}] |
\w | |
| [:xdigit:] | Hexadecimal digits | [A–Fa–f0–9] | [A–Fa–f0–9] | \p{XDigit} |
原创文章，作者：N27_what，如若转载，请注明出处：http://www.178linux.com/79453
