Linux Regular Expressions

Linux Regular Expressions

Character match:

.: Match any single character

[]: Matches any single character in the specified range;

[^]: Match any single character out of the specified range [: digit:] lower upper alpha alnum space

Matching times: used after the characters whose occurrences are to be specified and used to limit the occurrences of the previous characters

*: Match the first character any time: 0, 1. Multiple times

. *: Match any character of any length

\? : Match the first character 0 or once, and the first character is optional

\ +: Match the first character once or multiple times, at least once,

\ {M \} matches the previous character m times

\ {M. n \} matches the character above it at least m times, n times

\ {0, n \}: n times

\ {M, \}: At least m times

Positioning:

^: The beginning of the line is anchored to the left of the mode.

$: Anchor at the end of the line: used at the rightmost of the Mode

^ PATTERN: used for PATTERN

^ $: Blank line

^ [[: Space:]: empty line or blank line

Word: a continuous character (string) consisting of non-special characters is a word.

\ <Or \ B: the beginning of the word, used on the left side of the word mode

\> Or \ B: The end of the word, used to the right of the Word Pattern

\ <PATTERN \>: match the complete word

The above is a basic Regular Expression in Linux introduced by xiaobian. I hope it will be helpful to you. If you have any questions, please leave a message and I will reply to you in a timely manner. Thank you very much for your support for the help House website!