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Regular Expressions Cookbook, 2nd Edition
book

Regular Expressions Cookbook, 2nd Edition

by Jan Goyvaerts, Steven Levithan
August 2012
Intermediate to advanced content levelIntermediate to advanced
609 pages
19h 16m
English
O'Reilly Media, Inc.
Content preview from Regular Expressions Cookbook, 2nd Edition

8.18. Validate Windows Paths

Problem

You want to check whether a string looks like a valid path to a folder or file on the Microsoft Windows operating system.

Solution

Drive letter paths

\A
[a-z]:\\                    # Drive
(?:[^\\/:*?"<>|\r\n]+\\)*   # Folder
[^\\/:*?"<>|\r\n]*          # File
\Z
Regex options: Free-spacing, case insensitive
Regex flavors: .NET, Java, PCRE, Perl, Python, Ruby
^[a-z]:\\(?:[^\\/:*?"<>|\r\n]+\\)*[^\\/:*?"<>|\r\n]*$
Regex options: Case insensitive
Regex flavors: .NET, Java, JavaScript, PCRE, Perl, Python

Drive letter and UNC paths

\A
(?:[a-z]:|\\\\[a-z0-9_.$\-]+\\[a-z0-9_.$\-]+)\\  # Drive
(?:[^\\/:*?"<>|\r\n]+\\)*                           # Folder
[^\\/:*?"<>|\r\n]*                                  # File
\Z
Regex options: Free-spacing, case insensitive
Regex flavors: .NET, Java, PCRE, Perl, Python, Ruby
^(?:[a-z]:|\\\\[a-z0-9_.$-]+\\[a-z0-9_.$-]+)\\(?:[^\\/:*?"<>|\r\n]+\\)*↵
[^\\/:*?"<>|\r\n]*$
Regex options: Case insensitive
Regex flavors: .NET, Java, JavaScript, PCRE, Perl, Python

Drive letter, UNC, and relative paths

\A
(?:(?:[a-z]:|\\\\[a-z0-9_.$\-]+\\[a-z0-9_.$\-]+)\\|  # Drive
   \\?[^\\/:*?"<>|\r\n]+\\?)                           # Relative path
(?:[^\\/:*?"<>|\r\n]+\\)*                              # Folder
[^\\/:*?"<>|\r\n]*                                     # File
\Z
Regex options: Free-spacing, case insensitive
Regex flavors: .NET, Java, PCRE, Perl, Python, Ruby
^(?:(?:[a-z]:|\\\\[a-z0-9_.$-]+\\[a-z0-9_.$-]+)\\|\\?[^\\/:*?"<>|↵
\r\n]+\\?)(?:[^\\/:*?"<>|\r\n]+\\)*[^\\/:*?"<>|\r\n]*$
Regex options: Case insensitive
Regex flavors: .NET, Java, JavaScript, PCRE, Perl, Python

Discussion

Drive letter paths

Matching a full path to a file ...

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Publisher Resources

ISBN: 9781449327453Supplemental ContentErrata Page