Shell Regular Expression

Shell Common Regular Expressions

Common Regular expression ^        # line Header locates $       # end of row.       # match any character except line break *      # match 0 or more repeating characters +       # Repeat once or more?       # repeat 0 times or once?         # end the greedy factor. *? Represents a minimum match []      # matches any one of the characters in a set [^]      # Matches characters not in the specified group \      # used to escape metacharacters <      # Word-head Locators (Support VI and grep)  <love>      # Final Locator (Support VI and grep)  love>x\{m\}        # repeated occurrences m times x\{m,\}       # repeated occurrences at least m times x\{m,n\}      # repeats at least m times not more than n x?       # match occurs 0 times or once in uppercase letters xx+       # matches one or more letters X ()            # The characters within the parentheses for a set (Ab|de) +      # match a series of (at least one) ABC or DEF;ABC and Def will match [[: alpha:]]< c23/># stands for all letters regardless of the case [[: Lower:]    # = lowercase letters [[: Upper:]]    # means uppercase [[:d Igit:]] #    denotes numeric characters [[:d Igit:][:lower:]]    

Metacharacters

\d   # matches any one digit \d # matches any   single non-numeric character \w   # matches any single alphanumeric underscore character, synonym is [: alnum:]\w    # matches non-numeric characters

Character classes: whitespace characters

\s    # matches any whitespace    character \s # matches non-whitespace characters \b    # matches the beginning or end of a word \ n # matches a    newline character \ r    # matches a carriage return \ t    # match tab \b    # match backspace    # match a null value character

Character classes: Anchoring characters

\b    # Match word boundary (not in []) \b    # matches non-word boundary \a    # Match string beginning \z    # Match string or end of line \z    # Match string only end \g    # Match Previous m// g Where to leave

　Capture

(exp)                # match Exp, and capture text into the automatically named group (? <name>exp)         # Match exp, and capture the text to a group named name, you can also write (? ' Name ' Exp ' (?: exp)              # matches exp, does not capture matched text, and does not assign group numbers to this group

0 Wide Assertion

(? =exp)              # match exp front position (? <=exp)             # Match exp back to position (?! EXP)              # match the position followed by the exp (? <!exp)             # match the location (? #comment) that is not in front of exp (?) # Comments do not         have any effect on the processing of regular expressions for commenting

　Special characters

Http://en.wikipedia.org/wiki/ascii_table^h  \010 \b  ^m  \015 \ R matches special characters: Ctrl + V CTRL does not press H or M to output ^h for matching

　　

Shell Regular Expression