RegEXP
Computer programming #code/regexp
Liks
Special Characters
. [ { ( ) \ ^ $ | ? * +
| symbol | function | example |
|---|---|---|
| \ | Escape symbol - makes the next character literal | \. dot \* star \\ backslash |
General tokens
| symbol | function | example |
|---|---|---|
| \n | Newline | |
| \N | Anything but a newline | |
| \t | Tab | |
| \0 | Null character |
Meta sequences
| symbol | function | example |
|---|---|---|
| . | Any single character other than newline (or including line terminators with the /s flag) | /.+/ = a b c |
| a|b | a OR b | |
| \s | Any whitespace | |
| \S | Any non-whitespace | |
| \d | Any digit | |
| \D | Any non-digit | |
| \w | Any word character | |
| \W | Any non-word character | |
| \h | Horizontal whitespace character | |
| \r | Carriage return | |
| \R | Unicode newlines |
Character classes
| symbol | function | example |
|---|---|---|
| [abc] | A single character of a b c | |
| [^abc] | A character except a b c | |
| [a-zA-Z] | A character in range a - z or A-Z | |
| [a-z] | A character in range a - z | |
| [^a-z] | A character not in range a - z | |
| :<: | Start of word. POSIX equivalent of the \b (word boundary) is interpreted as \b(?=\w) |
|
| :>: | End of word. POSIX equivalent of the \b word boundary is interpreted as \\b(?<=\\w) |
|
| :alnum: | Letters and digits. Equivalent to [A-Za-z0-9] |
|
| :alpha: | Letters. Equivalent to [A-Za-z]. |
|
| :ascii: | ASCII codes 0 - 127. Equivalent to [\x00-\x7F] |
|
| :blank: | Space or Tab only (not new lines). Equivalent to [ \t] |
|
| :word: | Word character, letters, numbers, underscores. POSIX equivalent to \w or [a-zA-Z0-9_] |
|
| :punct: | Matches characters that are not whitespace, letters or numbers. |
Quantifiers
| symbol | function | example |
|---|---|---|
| a? | Zero or onw of a. | .? = Zero or one any characters |
| a* | Zero or more of a. Greedy quantifier - matches as many characters as possible |
|
| a+ | One or more of a | |
| a | Exactly 3 of a | |
| a | 3 or more of a | |
| a | Between 3 and 6 of a | |
| a*? | Lazy quantifier - matches as few characters as possible | |
| a*+ | Possessive quantifier |
Anchors
| symbol | function | example |
|---|---|---|
| \b | A word boundary | |
| \B | Non-word boundary | |
| ^ or \A | Start of string | |
| $ or \Z | End of string | |
| \z | Absolute end of string |
Groups
| symbol | function | example |
|---|---|---|
| (?: ...) | Match anything enclosed | |
| (...) | Capture anything enclosed |
Substitution
| symbol | function | example |
|---|---|---|
| $1 | Contents of capture group 1 | |
| $` | Contents before match | |
| $' | Contents after match | |
| $& | Complete match content | |
| \x20 | Hexadecimal replacement values | |
| \x | Hexadecimal replacement values | |
| \t | Insert Tab | |
| \r | Insert carriage return | |
| \n | Insert Newline | |
| \f | Insert form-feed |
Character Escapes
| symbol | code | meaning |
|---|---|---|
| \a | \u007 | bell |
| \b | \u008 | Backspace |
| \t | \u009 | Tab |
| \r | \u00D | CR |
| \v | \u00B | Vertical tab |
| \f | \u00C | Formfeed |
| \n | \u00A | NL |
| \e | \u001B | Escape |
| \nNN | Octal character | |
| \xNN | Hex character | |
| \uNNNN | Unicode character |
Modifiers
| symbol | function | example |
|---|---|---|
| g | Global | |
| m | Multiline | |
| i | Case sensitive | |
| u | Unicode | |
| U | Ungreedy | |
| x | Ignore whitespace/verbose |
Useful ones
Get array content without parenthesis per word
(?:\[([^\]]+)\]) /gm
*"(\w+)": "?(\w*)"?,/gm
MySQL : table structure parser
^(\w+)\s+(\w+)(\(\d*\))?.*$
^\w{4,}@+\w{2,}(.com|.co.uk|.net|.info|.xyz)$ gm
Regex of email with ability to add gmail's +example system
root email = user@gmail.com gmail+ = user+extra@gmail.com
^[a-zA-Z0-9_.]+[+]?[a-zA-Z0-9]+[@]{1}[a-z0-9]+[\.][a-z]+$ /gm
[a-z0-9!#$%&'*+/=?^_`{|}~-]+(?:\.[a-z0-9!#$%&'*+/=?^_`{|}~-]+)*@(?:[a-z0-9](?:[a-z0-9-]*[a-z0-9])?\.)+[a-z0-9](?:[a-z0-9-]*[a-z0-9])? /g
\b(?:(?:2(?:[0-4][0-9]|5[0-5])|[0-1]?[0-9]?[0-9])\.){3}(?:(?:2([0-4][0-9]|5[0-5])|[0-1]?[0-9]?[0-9]))\b /ig
\b(?:(25[0-5]|2[0-4][0-9]|[01]?[0-9]?[0-9])\.(25[0-5]|2[0-4][0-9]|[01]?[0-9]?[0-9])\.(25[0-5]|2[0-4][0-9]|[01]?[0-9]?[0-9])\.(25[0-5]|2[0-4][0-9]|[01]?[0-9]?[0-9]))|\:(\d*)\b /g
^(?1)){1,6}$ /gmi
^(?:[[:xdigit:{1,4}:){5}:(?:[[:xdigit:{1,4}:){1,6}:$ /gm
<.*?script.*\/?> /ig
^\s*(?:\+?(\d{1,3}))?([-. (]*(\d{3})[-. )]*)?((\d{3})[-. ]*(\d{2,4})(?:[-.x ]*(\d+))?)\s*$ /gm
(?:https?:\/\/)?(?:(?:(?:www\.?)?youtube\.com(?:\/(?:(?:watch\?.*?(v=[^&\s]+).*)|(?:v(\/.*))|(channel\/.+)|(?:user\/(.+))|(?:results\?(search_query=.+))))?)|(?:youtu\.be(\/.*)?))
(\[((?:\[^\[\)*)\]\([ \t]*()<?((?:\([^)]*\)|[^()\s])*?)>?[ \t]*((['"])(.*?)\6[ \t]*)?\)) /g
\/\/(?![\S]{2,}\.[\w]).*|\/\*(.|\n)+?\*\/ /g
(?:\s)\s /g
\b0x(?:[0-9A-Fa-f]{6}|0-9A-Fa-f]{8})\b