The bracket character set in Linux

The bracket character set in Linux:

[:d Igit:] numeric characters, 0-9;

[: Lower:] Lowercase alphabetic characters, A-Z;

[: Upper:] Uppercase characters, A-Z;

[: Alpha:] Uppercase and lowercase alphabetic characters, a-za-z;

[: Alnum:] numbers, alphabetic characters, 0-9a-za-z;

[: Space:] Blank (whitespace) character;

[: Blank:] Space (space) and Positioning (tab) characters;

[: Graph:] non-whitespace (nospace) characters;

[:p UNCT:] punctuation characters;

[:p rint:] printable characters;

[: Cntrl:] control character;

[: xdigit:] hexadecimal character;

Test file:

[email protected] ~]# cat test 123123 abcabc #此行有空格; abc123abc ABC abcABC123 123 ABCA,B.C #此行无空格; AAbb.

Example 1:[:d igit:] numeric character, 0-9;

[[email protected] ~]# grep ' [[:d igit:] ' test 123123 abcabc123abc123 123 AbC

Example 2:[:lower:] Lowercase alphabetic characters, A-Z;

[[email protected] ~]# grep ' [[: Lower:] ' test 123 ABCABC ABC123ABC ABC 123 Abca,b.caabb.

Example 3:[:upper:] Uppercase characters, A-Z;

[[email protected] ~]# grep ' [[: Upper:] ' test abc abc abcABC123 123 Abcaabb.

Example 4:[:alpha:] Uppercase and lowercase alphabetic characters, a-za-z;

[[email protected] ~]# grep ' [[: Alpha:]] ' test 123 abcabc abc123abc ABC abcABC123 123 Abca,b.caabb.

Example 5:[:alnum:] numbers, alphabetic characters, 0-9a-za-z;

[[email protected] ~]# grep ' [[: Alnum:] ' test 123123 abcabcabc123abc ABC abcABC123 123 Abca,b.caabb.

Example 6:[:space:] Blank (whitespace) character;

[[email protected] ~]# grep ' [[: Space:]] ' test 123 ABC abc abc ABC 123 ABC

Example 7:[:blank:] Space (space) and Positioning (tab) characters;

[[email protected] ~]# grep ' [[: Blank:]] ' test 123 ABC abc abc ABC 123 ABC

Example 8:[:graph:] Non-whitespace (nospace) characters;

[[email protected] ~]# grep ' [[: Graph:]] ' test 123123 abcabcabc123abc ABC abcABC123 123 Abca,b.caabb.

Example 9:[:p UNCT:] punctuation characters;

[[email protected] ~]# grep ' [[:p UNCT:] ' Test A,b.caabb.

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The bracket character set in Linux