Programação, PHP, Javascript, HTML, CSS, Python
Funções
| preg_match(pattern, subject[, submatches]) |
| preg_match_all(pattern, subject[, submatches]) |
| preg_replace(pattern, replacement, subject) |
| preg_replace_callback(pattern, callback, subject) |
| preg_grep(pattern, array) |
| preg_split(pattern, subject) |
Meta Characteres
| ^ |
Start of subject (or line in multiline mode) |
| $ |
End of subject (or line in multiline mode) |
| [ |
Start character class definition |
| ] |
End character class definition |
| | |
Alternates, eg (a|b) matches a or b |
| ( |
Start pattern |
| ) |
End subpattern |
| \ |
Escape character |
Pattern Modifiers
| i |
Caseless – ignore case |
| m |
Multiline mode – ^ and $ match start and end of lines |
| s |
Dotall – . class includes newline |
| x |
Extended – comments & whitespace |
| e |
preg_replace only – enables evaluation of replacement as PHP code |
| S |
Extra analysis of pattern |
| U |
Pattern is ungreedy |
| u |
Pattern is treated as UTF-8 |
Base Character Classes
| \w |
Any “word” character (a-z 0-9 _) |
| \W |
Any non “word” character |
| \s |
Whitespace (space, tab CRLF) |
| \S |
Any non whitespace character |
| \d |
Digits (0-9) |
| \D |
Any non digit character |
| . |
(Period) – Any character except newline |
Quantifiers
| n* |
Zero or more of n |
| n+ |
One or more of n |
| n? |
Zero or one occurrences of n |
| {n} |
n occurrences exactly |
| {n,} |
At least n occurrences |
| {,m} |
At most m occurrences |
| {n,m} |
Between n and m occurrences (inclusive) |
Point based assertions
| \b |
Word boundary |
| \B |
Not a word boundary |
| \A |
Start of subject |
| \Z |
End of subject or newline at end |
| \z |
End of subject |
| \G |
First matching position in subject |
Subpattern Modifiers & Assertions
| (?:) |
Non capturing subpattern |
((?:foo|fu)bar) matches foobar or fubar without foo or fu appearing as a captured subpattern |
| (?=) |
Positive look ahead assertion |
foo(?=bar) matches foo when followed by bar |
| (?!) |
Negative look ahead assertion |
foo(?!bar) matches foo when not followed by bar |
| (?<=) |
Positiove look behind assertion |
(?<=foo)bar matches bar when proceded by foo |
| (?<!) |
Negative look behind |
(?<!foo)bar matches bar when not proceded by foo |
| (?>) |
Once-only subpatterns |
(?>d+)bar Performance enhacing when bar not present |
| (?(x)) |
Condition subpatterns |
(?(3)foo|fu)bar Matches foo if 3rd subpattern has matches, fu if not |
| (?#) |
Comment |
(?# Pattern does x y or z) |
Referências
