Practice Makes Regexp

206 Pages·5.868 MB·English

by  Reuven M. Lerner

Practice Makes Regexp
50 exercises to help you master regular
expressions
Reuven M. Lerner, PhD
Contents
Preface: Practice Makes Regexp
1 About me
2 Acknowledgements
Chapter 1 Regexp use from programming languages
1.1 Python
1.1.1 Defining regexps
1.1.2 Finding one
1.1.3 Finding more than one
1.1.4 Substituting text
1.1.5 Flags
1.1.6 Advanced features
1.1.7 More information
1.1.8 About Python solutions
1.2 Ruby
1.2.1 Defining regexps
1.2.2 Finding one
1.2.3 Finding more than one
1.2.4 Substituting text
1.2.5 Flags
1.2.6 Advanced features
1.2.7 More information
1.2.8 About Ruby solutions
1.3 JavaScript
1.3.1 Defining regexps
1.3.2 Finding one or more
1.3.3 Substituting text
1.3.4 Advanced features
1.3.5 More information
1.3.6 About JavaScript solutions
1.4 PostgreSQL
1.4.1 Defining regexps
1.4.2 True/false operators
1.4.3 Extracting text
1.4.4 Splitting
1.4.5 More information
1.5 grep
1.5.1 Basic use
1.5.2 Backslashes
1.5.3 Context
Chapter 2 Input data
2.1 Dictionary (words.txt)
2.2 Alice in Wonderland (alice.txt)
2.3 Config (config.txt)
2.4 Apache logfile (access-log.txt)
2.5 Linux “passwd” file (passwd.txt)
2.6 Fakelog (fakelog.txt)
2.7 PostgreSQL database
Chapter 3 Exercises
3.1 Simple regexps
3.1.1 Find matches
3.1.2 Five-letter words
3.1.3 Double “f” in the middle
3.1.4 Extract timestamp
3.2 Character classes
3.2.1 End-of-sentence words
3.2.2 Hex numbers
3.2.3 Hexwords
3.2.4 IP addresses
3.2.5 Long, weird words
3.2.6 Matching URLs
3.2.7 Non-zero hours
3.2.8 Quoted text
3.2.9 Supervocalic
3.2.10 Double triple vowel
3.2.11 Postfix dollar
3.3 Alternation
3.3.1 Multiple date formats
3.3.2 “oo” and “ee” words
3.3.3 British and American spelling
3.4 Anchors
3.4.1 Capital vowel starts
3.4.2 Comment lines
3.4.3 Last five characters
3.4.4 u in the 2nd-to-last word
3.5 Groups
3.5.1 Date and time
3.5.2 Config pairs
3.5.3 Quote first and last words
3.5.4 Prices with symbols
3.5.5 Question first word
3.5.6 t, but no “ing”
3.5.7 Usernames and user IDs
3.5.8 Beheaded usernames
3.5.9 Final question words
3.5.10 “d” user shells
3.6 Flags
3.6.1 All usernames
3.6.2 abc
3.6.3 abcABC
3.6.4 abcABC, extended
3.6.5 No-error IP addresses
3.7 Backreferences
3.7.1 Doubled vowels
3.7.2 Hours and seconds
3.7.3 Seven-letter start-finish words
3.7.4 end-start
3.7.5 Singular and plural
3.8 Replace
3.8.1 Crunch whitespace
3.8.2 New hostname
3.8.3 Detagify
3.8.4 Deunixify paths
3.9 Unix command line
3.9.1 Disk space
3.9.2 Not-today files
3.9.3 Problem logs
3.9.4 Old and new Office files
Chapter 4 Simple regexps
4.1 Find matches
4.1.1 Solution
4.1.2 Python
4.1.3 Ruby
4.1.4 JavaScript
4.1.5 PostgreSQL
4.2 Five-letter words
4.2.1 Solution
4.2.2 Python
4.2.3 Ruby
4.2.4 JavaScript
4.2.5 PostgreSQL
4.3 Double “f” in the middle
4.3.1 Solution
4.3.2 Python
4.3.3 Ruby
4.3.4 JavaScript
4.3.5 PostgreSQL
4.4 Extract timestamp
4.4.1 Solution
4.4.2 Python
4.4.3 Ruby
4.4.4 JavaScript
4.4.5 PostgreSQL
Chapter 5 Character classes
5.1 End-of-sentence words
5.1.1 Solution
5.1.2 Python
5.1.3 Ruby
5.1.4 JavaScript
5.1.5 PostgreSQL
5.2 Hex numbers
5.2.1 Solution
5.2.2 Python
5.2.3 Ruby
5.2.4 JavaScript
5.2.5 PostgreSQL
5.3 Hexwords
5.3.1 Solution
5.3.2 Python
5.3.3 Ruby
5.3.4 JavaScript
5.3.5 PostgreSQL
5.4 IP addresses
5.4.1 Solution
5.4.2 Python
5.4.3 Ruby
5.4.4 JavaScript
5.4.5 PostgreSQL
5.5 Long, weird words
5.5.1 Solution
5.5.2 Python
5.5.3 Ruby
5.5.4 JavaScript
5.5.5 PostgreSQL
5.6 Matching URLs
5.6.1 Solution
5.6.2 Python
5.6.3 Ruby
5.6.4 JavaScript
5.6.5 PostgreSQL
5.7 Non-zero hours
5.7.1 Solution
5.7.2 Python
5.7.3 Ruby
5.7.4 JavaScript
5.7.5 PostgreSQL
5.8 Quoted text
5.8.1 Solution
5.8.2 Python
5.8.3 Ruby
5.8.4 JavaScript
5.8.5 PostgreSQL
5.9 Supervocalic
5.9.1 Solution
5.9.2 Python
5.9.3 Ruby
5.9.4 JavaScript
5.9.5 PostgreSQL
5.10 Double triple vowel
5.10.1 Solution
5.10.2 Python
5.10.3 Ruby
5.10.4 JavaScript
5.10.5 PostgreSQL
5.11 Postfix dollar
5.11.1 Solution
5.11.2 Python
5.11.3 Ruby
5.11.4 JavaScript
5.11.5 PostgreSQL