Downloaded 157 times
![Regular expressions are
patterns
used to match
character combinations
in strings[1].
What it is?](https://image.slidesharecdn.com/regexfundamentalmesutgunes-170117111153/85/Regular-Expression-Regex-Fundamentals-2-320.jpg)
![1956: Stephen Cole Kleene, Regular
Language
1968: Ken Thompson, Pattern Matching,
Text editor
1970: Bell Labs, in Unix
1980: Henry Spencer, PERL
1992: POSIX.2 (UNIX Shell), Many
languages [2]
History](https://image.slidesharecdn.com/regexfundamentalmesutgunes-170117111153/85/Regular-Expression-Regex-Fundamentals-3-320.jpg)
![^ $ . | { } [ ] ( ) * + ?
Literal Characters
(metacharacters)](https://image.slidesharecdn.com/regexfundamentalmesutgunes-170117111153/85/Regular-Expression-Regex-Fundamentals-8-320.jpg)
![provide a list of potential
matching characters at a
position in the search
text
Square Brackets
7[Pp][Mm]](https://image.slidesharecdn.com/regexfundamentalmesutgunes-170117111153/85/Regular-Expression-Regex-Fundamentals-9-320.jpg)
![more examples
Square Brackets
7[Pp][Mm]
[123456789][aApP][Mm]
[1-9][aApP][Mm]](https://image.slidesharecdn.com/regexfundamentalmesutgunes-170117111153/85/Regular-Expression-Regex-Fundamentals-10-320.jpg)
![provide list of
excludation
Negation
[^0-9A-F]
[^a-zA-Z0-9_] negative of w (or
W)](https://image.slidesharecdn.com/regexfundamentalmesutgunes-170117111153/85/Regular-Expression-Regex-Fundamentals-12-320.jpg)
![define the string
boundaries
Starting and Ending Pattern
^ : starting string, not inside []
$ : end of string](https://image.slidesharecdn.com/regexfundamentalmesutgunes-170117111153/85/Regular-Expression-Regex-Fundamentals-15-320.jpg)
![(x|y|z) vs [xyx]
Alternation
(x|y|z) : can be used for string
[xyz][a-A0-9] : one character or
list of characters
(Regex|ReGex) - Re[gG]ex](https://image.slidesharecdn.com/regexfundamentalmesutgunes-170117111153/85/Regular-Expression-Regex-Fundamentals-17-320.jpg)
![[abc]
A single character: a, b, or c](https://image.slidesharecdn.com/regexfundamentalmesutgunes-170117111153/85/Regular-Expression-Regex-Fundamentals-19-320.jpg)
![[^abc]
Any single character but a, b, or c](https://image.slidesharecdn.com/regexfundamentalmesutgunes-170117111153/85/Regular-Expression-Regex-Fundamentals-20-320.jpg)
![[a-z]
Any single character in the range
a-z](https://image.slidesharecdn.com/regexfundamentalmesutgunes-170117111153/85/Regular-Expression-Regex-Fundamentals-21-320.jpg)
![[a-zA-Z]
Any single character in the range a-z or
A-Z](https://image.slidesharecdn.com/regexfundamentalmesutgunes-170117111153/85/Regular-Expression-Regex-Fundamentals-22-320.jpg)
![check if the pattern follows by
another
Look Ahead
(?=<pattern>) : positive look ahead
(?!<pattern>) : negative look ahead
(?<city>w+)[, ]+(?= NJ|PA|DE)](https://image.slidesharecdn.com/regexfundamentalmesutgunes-170117111153/85/Regular-Expression-Regex-Fundamentals-40-320.jpg)
![check if the pattern precede by
another
Look Behind
(?<=<pattern>) : positive look ahead
(?<!<pattern>) : negative look ahead
(?<="state":)[
].*(?<state>PA|Pennsylvania)](https://image.slidesharecdn.com/regexfundamentalmesutgunes-170117111153/85/Regular-Expression-Regex-Fundamentals-41-320.jpg)
![ack '(?<="GET")[,]"/nike.*'
unix shell
Find all “GET” requests to “nike” in all .csv files:
~/Downloads ls *.csv | wc -l
109
~/Downloads ack '(?<="GET")[,]"/nike.*' | wc -l
88
~/Downloads cat web_3000:25.csv | grep '/nike.*'
"GET","/arama/nike",7,0,140,665,101,3797,196168,0.09
"GET","/kampanya/arama/nike",8,0,270,678,229,2641,164205,0.11
"GET","/nike/295/morhipo-ozel",2,0,81,88,81,95,121609,0.03
"GET","/nike/markalar/503/32026/marka?fh=discount_rate_catalog01]](https://image.slidesharecdn.com/regexfundamentalmesutgunes-170117111153/85/Regular-Expression-Regex-Fundamentals-45-320.jpg)
![^/(Questions|Sorular|$/*)پرسش
Thanks
Reference:
[1] https://developer.mozilla.org/en/docs/Web/JavaScript/Guide/Regular_Expressions
[2] https://en.wikipedia.org/wiki/Regular_expression
[3] Regular Expression Succinctly, Syncfusion, by Joe Both
[4] http://www.slideshare.net/adamlowe/regex-cards-powerpoint-format
[5] https://regex101.com
Mesut Güneş
www.testrisk.com](https://image.slidesharecdn.com/regexfundamentalmesutgunes-170117111153/85/Regular-Expression-Regex-Fundamentals-47-320.jpg)
![Regular expressions are
patterns
used to match
character combinations
in strings[1].
What it is?](https://image.slidesharecdn.com/regexfundamentalmesutgunes-170117111153/75/Regular-Expression-Regex-Fundamentals-2-2048.jpg)
![1956: Stephen Cole Kleene, Regular
Language
1968: Ken Thompson, Pattern Matching,
Text editor
1970: Bell Labs, in Unix
1980: Henry Spencer, PERL
1992: POSIX.2 (UNIX Shell), Many
languages [2]
History](https://image.slidesharecdn.com/regexfundamentalmesutgunes-170117111153/75/Regular-Expression-Regex-Fundamentals-3-2048.jpg)
![^ $ . | { } [ ] ( ) * + ?
Literal Characters
(metacharacters)](https://image.slidesharecdn.com/regexfundamentalmesutgunes-170117111153/75/Regular-Expression-Regex-Fundamentals-8-2048.jpg)
![provide a list of potential
matching characters at a
position in the search
text
Square Brackets
7[Pp][Mm]](https://image.slidesharecdn.com/regexfundamentalmesutgunes-170117111153/75/Regular-Expression-Regex-Fundamentals-9-2048.jpg)
![more examples
Square Brackets
7[Pp][Mm]
[123456789][aApP][Mm]
[1-9][aApP][Mm]](https://image.slidesharecdn.com/regexfundamentalmesutgunes-170117111153/75/Regular-Expression-Regex-Fundamentals-10-2048.jpg)
![provide list of
excludation
Negation
[^0-9A-F]
[^a-zA-Z0-9_] negative of w (or
W)](https://image.slidesharecdn.com/regexfundamentalmesutgunes-170117111153/75/Regular-Expression-Regex-Fundamentals-12-2048.jpg)
![define the string
boundaries
Starting and Ending Pattern
^ : starting string, not inside []
$ : end of string](https://image.slidesharecdn.com/regexfundamentalmesutgunes-170117111153/75/Regular-Expression-Regex-Fundamentals-15-2048.jpg)
![(x|y|z) vs [xyx]
Alternation
(x|y|z) : can be used for string
[xyz][a-A0-9] : one character or
list of characters
(Regex|ReGex) - Re[gG]ex](https://image.slidesharecdn.com/regexfundamentalmesutgunes-170117111153/75/Regular-Expression-Regex-Fundamentals-17-2048.jpg)
![[abc]
A single character: a, b, or c](https://image.slidesharecdn.com/regexfundamentalmesutgunes-170117111153/75/Regular-Expression-Regex-Fundamentals-19-2048.jpg)
![[^abc]
Any single character but a, b, or c](https://image.slidesharecdn.com/regexfundamentalmesutgunes-170117111153/75/Regular-Expression-Regex-Fundamentals-20-2048.jpg)
![[a-z]
Any single character in the range
a-z](https://image.slidesharecdn.com/regexfundamentalmesutgunes-170117111153/75/Regular-Expression-Regex-Fundamentals-21-2048.jpg)
![[a-zA-Z]
Any single character in the range a-z or
A-Z](https://image.slidesharecdn.com/regexfundamentalmesutgunes-170117111153/75/Regular-Expression-Regex-Fundamentals-22-2048.jpg)
![check if the pattern follows by
another
Look Ahead
(?=<pattern>) : positive look ahead
(?!<pattern>) : negative look ahead
(?<city>w+)[, ]+(?= NJ|PA|DE)](https://image.slidesharecdn.com/regexfundamentalmesutgunes-170117111153/75/Regular-Expression-Regex-Fundamentals-40-2048.jpg)
![check if the pattern precede by
another
Look Behind
(?<=<pattern>) : positive look ahead
(?<!<pattern>) : negative look ahead
(?<="state":)[
].*(?<state>PA|Pennsylvania)](https://image.slidesharecdn.com/regexfundamentalmesutgunes-170117111153/75/Regular-Expression-Regex-Fundamentals-41-2048.jpg)
![ack '(?<="GET")[,]"/nike.*'
unix shell
Find all “GET” requests to “nike” in all .csv files:
~/Downloads ls *.csv | wc -l
109
~/Downloads ack '(?<="GET")[,]"/nike.*' | wc -l
88
~/Downloads cat web_3000:25.csv | grep '/nike.*'
"GET","/arama/nike",7,0,140,665,101,3797,196168,0.09
"GET","/kampanya/arama/nike",8,0,270,678,229,2641,164205,0.11
"GET","/nike/295/morhipo-ozel",2,0,81,88,81,95,121609,0.03
"GET","/nike/markalar/503/32026/marka?fh=discount_rate_catalog01]](https://image.slidesharecdn.com/regexfundamentalmesutgunes-170117111153/75/Regular-Expression-Regex-Fundamentals-45-2048.jpg)
![^/(Questions|Sorular|$/*)پرسش
Thanks
Reference:
[1] https://developer.mozilla.org/en/docs/Web/JavaScript/Guide/Regular_Expressions
[2] https://en.wikipedia.org/wiki/Regular_expression
[3] Regular Expression Succinctly, Syncfusion, by Joe Both
[4] http://www.slideshare.net/adamlowe/regex-cards-powerpoint-format
[5] https://regex101.com
Mesut Güneş
www.testrisk.com](https://image.slidesharecdn.com/regexfundamentalmesutgunes-170117111153/75/Regular-Expression-Regex-Fundamentals-47-2048.jpg)
Uploaded byMesut Günes
Regular Expression (Regex) Fundamentals
The document provides a comprehensive overview of regular expressions (regex), detailing their history, syntax, and various use cases, particularly in text processing. It discusses the foundational concepts such as quantifiers, string boundaries, alternation, and character classes, along with practical examples. Additionally, it includes references for further reading and examples of regex applications in different contexts.
More Related Content
Similar to Regular Expression (Regex) Fundamentals
Regular Expression (Regex) Fundamentals
- 1.
- 2. Regular expressions are patterns usedto match character combinations in strings[1]. What it is?
- 3. 1956: Stephen ColeKleene, Regular Language 1968: Ken Thompson, Pattern Matching, Text editor 1970: Bell Labs, in Unix 1980: Henry Spencer, PERL 1992: POSIX.2 (UNIX Shell), Many languages [2] History
- 4. Hi, I called Jonon Tuesday, March 25th at 7pm and expressed a concern about my slow times accessing www.cnn.com. He said he would fix it, but I never heard back. Can someone contact me at Kellie.Booth@if.com ASAP? What does Ctrl-F5 mean, by the way? Thanks Kellie Human Brain VS Text Processing
- 5. Hi, …., thanks Icalled … March 27th ww.blabla.com Patterns?
- 6.
- 7.
- 8. ^ $ .| { } [ ] ( ) * + ? Literal Characters (metacharacters)
- 9. provide a listof potential matching characters at a position in the search text Square Brackets 7[Pp][Mm]
- 10.
- 11. provide characters cannotenter to regex Non-Printable Characters n - Matches a new line; Windows rn t - Matches a tab character. b - Matches a backspace (when used between brackets) a - Matches the bell character. r - Matches a carriage return. f - Matches Form feed. v - Matches a vertical tab. Euro € - u20AC British pound £ - u00A3 Yen ¥ -u00A5 Dollar sign $ - $ or u0024 or x24 cX - Matches an ASCII control character, such as cC is Ctrl-C.
- 12. provide list of excludation Negation [^0-9A-F] [^a-zA-Z0-9_]negative of w (or W)
- 13. repetition of characters Curly Brakets {n}: “n” times. {n,} : At least “n” times, but no upper limit. {n,m} : Between “n” and “m” times.
- 14. repetition characters Quantifier Symbols Quantifier MatchesSame as ? Match zero or one time {0,1} * Match zero or more times {0, } + Match one or more times {1, }
- 15. define the string boundaries Startingand Ending Pattern ^ : starting string, not inside [] $ : end of string
- 16.
- 17. (x|y|z) vs [xyx] Alternation (x|y|z): can be used for string [xyz][a-A0-9] : one character or list of characters (Regex|ReGex) - Re[gG]ex
- 18.
- 19. [abc] A single character:a, b, or c
- 20. [^abc] Any single characterbut a, b, or c
- 21. [a-z] Any single characterin the range a-z
- 22. [a-zA-Z] Any single characterin the range a-z or A-Z
- 23.
- 24.
- 25.
- 26.
- 27.
- 28.
- 29.
- 30.
- 31. w Any word character(letter, number, underscore)
- 32.
- 33. b Any word boundarycharacter
- 34.
- 35.
- 36.
- 37.
- 38.
- 39.
- 40. check if thepattern follows by another Look Ahead (?=<pattern>) : positive look ahead (?!<pattern>) : negative look ahead (?<city>w+)[, ]+(?= NJ|PA|DE)
- 41. check if thepattern precede by another Look Behind (?<=<pattern>) : positive look ahead (?<!<pattern>) : negative look ahead (?<="state":)[ ].*(?<state>PA|Pennsylvania)
- 42.
- 43. ^(?!.*(?:<|>|&|’|"|%|;|-|+|(|)|s)).{6,20}$ password should be 6to 20 characters length and not include the followings: < > & ’ ” % ; - + ( )
- 44. Let’s Dig-into Pattern EnglishRule Regex Pattern BEGINNING of the string ^ Start of NEGATIVE LOOKAHEAD (?! Multiple any word except newline, with QUANTIFIER .* Start of NON-CAPTURING group (?: Single CHARACTER with ALTERNATION <| More single CHARACTER with ALTERNATION >| &| ‘| “| %| ;| -| +| (| )| s Repetition with boundaries {6,20} END string $ ^(?!.*(?:<|>|&|'|"|%|;|-|+|(|)|s)).{6,20}$
- 45. ack '(?<="GET")[,]"/nike.*' unix shell Findall “GET” requests to “nike” in all .csv files: ~/Downloads ls *.csv | wc -l 109 ~/Downloads ack '(?<="GET")[,]"/nike.*' | wc -l 88 ~/Downloads cat web_3000:25.csv | grep '/nike.*' "GET","/arama/nike",7,0,140,665,101,3797,196168,0.09 "GET","/kampanya/arama/nike",8,0,270,678,229,2641,164205,0.11 "GET","/nike/295/morhipo-ozel",2,0,81,88,81,95,121609,0.03 "GET","/nike/markalar/503/32026/marka?fh=discount_rate_catalog01]
- 46.
- 47. ^/(Questions|Sorular|$/*)پرسش Thanks Reference: [1] https://developer.mozilla.org/en/docs/Web/JavaScript/Guide/Regular_Expressions [2] https://en.wikipedia.org/wiki/Regular_expression [3]Regular Expression Succinctly, Syncfusion, by Joe Both [4] http://www.slideshare.net/adamlowe/regex-cards-powerpoint-format [5] https://regex101.com Mesut Güneş www.testrisk.com