Programming Concepts: Pattern Matching Using Regular Expressions

Prerequisites

This course describes how patterns in text strings can be matched using regular expressions. A number of programming and scripting languages (such as Python, Perl, and Java) and other applications (such as Apache, PHP, Exim, and some text editors) support the use of regular expression patterns. Although there are some differences between the different implementations, there is also a lot in common.

The course has been modified and extended from the one previously given by Philip Hazel, the author of the PCRE ("Perl Compatible Regular Expressions") library, one of the standard and widely used regular expression libraries. The extensions are: Python and Java to the same level as Perl and PCRE; more warnings about problem areas, background usage and programming hints; and a short section on true (computer science) regular expressions and their uses when transferring data between programs.

Some programming or scripting experience using text as input (e.g. decoding arguments or input data).

Number of sessions: 2

• Brief introduction and history
• Basic character matching and encoding
• Repetition, assertions and alternation
• Capturing and using parts of the subject
• Extended parenthesis features and atomicity
• Lookahead, lookbehind and conditional matching
• Back references and recursion
• Different ways of matching a pattern
• Performance issues
• True regular expressions and data formats

Presentation

• More information may be found in http://www-uxsup.csx.cam.ac.uk/courses/REs/

Two half day sessions

• Programming and Scripting
• Scientific Computing
• Techlinks & IT Support Staff