The minute you think of giving up, think of the reason why you held on so long!
分类: LINUX
2016-06-11 22:59:04
[:alnum:] Alphanumeric characters.(匹配当前归类中的数字、大写和小写字母字符,等同于[A-Za-z0-9])
[:alpha:] Alphabetic characters.(匹配当前归类中的大写和小写字母字符,等同于[A-Za-z])
[:blank:] Space or tab characters.(匹配一个空白字符,或水平制表符。[[:blank:]] 等同于 [ \t])
[:cntrl:] Control characters.(匹配顺序值小于32或字符值为127的 ASCII 字符(控制字符)。控制字符包括换行符、换页符、退格符等等。)
[:digit:] Numeric characters.(匹配当前归类中的数字字符,等同于[0-9])
[:graph:] Characters that are both printable and visible. (A space is printable, but not visible, while an a is both.)(可打印的图形字符,非空格字符,匹配顺序值大于33小于127的 ASCII 字符)
[:lower:] Lower-case alphabetic characters.(匹配当前归类中的小写字母字符,等同于[a-z])
[:print:] Printable characters (characters that are not control characters.)(可打印的字符,匹配顺序值大于33小于127的 ASCII 字符)
[:punct:] Punctuation characters (characters that are not letter, digits, control characters, or space characters).(匹配标点符号字符)
[:space:] Space characters (such as space, tab, and formfeed, to name a few).(匹配任意空白字符,包含[:blank:])
[:upper:] Upper-case alphabetic characters.(匹配当前归类中的大写字母字符,等同于[A-Z])
[:xdigit:] Characters that are hexadecimal digits(匹配十六进制数字字符,等同于[0-9A-Fa-f])