5 f5模拟器regexgnu正则表达式.pdfVIP

1.1 Backslash Character (反斜杠字符) ⚫ \b ➔\brat\b matches the separate word rat. ⚫ \B ➔c\Brat\Be matches crate, but dirty \Brat doesnt match dirty rat. ⚫ \ ➔\ra match dirty rat. ⚫ \ ➔ty\ match dirty rat. ⚫ \w ➔ ‘\wat’ match ‘dirty rat’ ⚫ \W ➔ ‘\Wr match ‘dirty rat’ ⚫ \` and \’ ⚫ The Match-self Operator (ordinary character) ⚫ The Match-any-character Operator (.) ⚫ Repetition Operators (*,?,+,{,}) – * ➔ zero or more – + ➔ one or more – ? ➔ zero or one – {, } ➔ interval operators ⚫ a{3} → aaa ⚫ Alternation Operator ( | ) ⚫ List Operator ( [ …] or [^…] ) – Character Class Operator ( [: …:] ) – The Range Operator ( - ) – [abc] matches a, b, c – [a-z] matches lower case alpha – [^abc] matches any char but a,b,c ⚫ Character Class Operator ( [: … :] ) – alnum ：letters and digits – alpha ：letters – blank ：system-dependent; for GNU, a space or tab – cntrl ：control characters (in the ASCII encoding, code 0177 and codes less than 040) – digit ：digits – graph ：same as print except omits space – lower ：lowercase letters – print ：printable characters (in the ASCII encoding, space tilde--codes 040 through 0176) – punct ：neither control nor alphanumeric characters – space ：space, carriage return, newline, vertical tab, and form feed – upper ：uppercase letters – xdigit ：hexadecimal digits: 0--9, a--f, A--F ⚫ Grou Operators ( (…) ) ⚫ The Back-Reference Operators (\digit) – digit must b ween 1 and 9 – For example, `(one()|two())-and-(three\2|four\3) matches `one-and-three and `two-and-four, but not `one-and-four or `two-and-three. – `(.*)\ 1 matches what ? (Part1Part2) ⚫ Anchoring Operators ( ^, $ ) 2 Verify your regex (检验) ⚫ echo “string” | perl -i -p -e ‘s/regex/0/’ ⚫ echo fooqbarquux | perl -i -p -e s/(fooq|f