正则表达式在各种工具中的差异

+---------+---------+---------+---------+----------+---------+-----------------------------------+| sed | awk | perl | grep -P | vim | emacs | DESC |+---------+---------+---------+---------+----------+---------+-----------------------------------+|Special Characters |+------------------------------------------------------------+-----------------------------------+| . |any character in single line |+---------+---------+---------+---------+----------+---------+-----------------------------------+| [0-9] | [0-9] | /d | /d | /d | [0-9] |single digit |+---------+---------+---------+---------+----------+---------+-----------------------------------+| /w | /w | /w | /w | /w | /w |single word character [a-zA-Z0-9_] |+---------+---------+---------+---------+----------+---------+-----------------------------------+| [ /t] | [ /t] | /s | /s | /s | [ /t] |single white space |+---------+---------+---------+---------+----------+---------+-----------------------------------+|Grouping/Character Groups |+------------------------------------------------------------+-----------------------------------+| [...] |any character inside |+------------------------------------------------------------+-----------------------------------+| [^...] |any character not inside |+---------+---------+---------+---------+----------+---------+-----------------------------------+| /| | | | | | | | /| | /| |alternation |+---------+---------+---------+---------+----------+---------+-----------------------------------+| /(.../) | (...) | (...) | (...) | /(.../) | /(.../) |capturing for later references |+---------+---------+---------+---------+----------+---------+-----------------------------------+| N/A | N/A | (?:...) | (?:...) | /%(.../) |/(?:.../)|non-capturing group |+---------+---------+---------+---------+----------+---------+-----------------------------------+|Positions |+------------------------------------------------------------+-----------------------------------+| ^ |beginning of line |+------------------------------------------------------------+-----------------------------------+| $ |end of line |+---------+---------+---------+---------+----------+---------+-----------------------------------+| /< | /< | /b | /b | /< | /< |left word boundary |+---------+---------+---------+---------+----------+---------+-----------------------------------+| /> | /> | /b | /b | /> | /> |right word boundary |+---------+---------+---------+---------+----------+---------+-----------------------------------+|Repeaters |+------------------------------------------------------------+-----------------------------------+| * |0 or more times |+---------+---------+---------+---------+----------+---------+-----------------------------------+| N/A | ? | ? | ? | /= | ? |0 or 1 time |+---------+---------+---------+---------+----------+---------+-----------------------------------+| /+ | + | + | + | /+ | + |1 or more times |+---------+---------+---------+---------+----------+---------+-----------------------------------+| /{m,n/} | N/A | {m,n} | {m,n} | /{m,n} | N/A |m<= match times <=n |+---------+---------+---------+---------+----------+---------+-----------------------------------+|Non greedy match |+---------+---------+---------+---------+----------+---------+-----------------------------------+| N/A | N/A | *? | *? | /{-} | *? |non greedy match |+---------+---------+---------+---------+----------+---------+-----------------------------------+|Look-Ahead/Look-Behind Assertion |+---------+---------+---------+---------+----------+---------+-----------------------------------+| N/A | N/A | (?=...) | (?=...) |/(../)/@= | N/A |0 width positive look-ahead |+---------+---------+---------+---------+----------+---------+-----------------------------------+| N/A | N/A | (?!...) | (?!...) |/(../)/@! | N/A |0 width negative look-ahead |+---------+---------+---------+---------+----------+---------+-----------------------------------+| N/A | N/A |(?<=...) |(?<=...) |/(../)/@<=| N/A |0 width positive look-behind |+---------+---------+---------+---------+----------+---------+-----------------------------------+| N/A | N/A |(?<!...) |(?<!...) |/(../)/@<!| N/A |0 width negative look-behind |+---------+---------+---------+---------+----------+---------+-----------------------------------+| sed | awk | perl | grep -P | vim | emacs | DESC |+---------+---------+---------+---------+----------+---------+-----------------------------------+