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_HowToUseRegularExpressions

_HowToUseRegularExpressions

Owned by Former user (Deleted)
Jul 03, 2019

Overview

A number of apps provide advanced features that require the use of regular expressions for pattern matching. Generally, just a simple understanding of regular expressions and a few examples are enough to get by for most use cases. This will just give a few simple examples to get started. Use the references for more advanced information. We recommend using one of the regex test sites (we do all the time!!!) - RegexPlanet or Regex101.

Regex for workflow conditions

For JIRA workflow functions using regex expressions to condition whether the post function should continue processing, a blank pattern means that condition processing is not done and processing should continue.



Key tips

  • Dot or period (.) is a special regex character. If you really want to match on it, you need to escape it with a backslash: \.

  • Don't be confused with generic pattern matching used for file systems for instance. On a file system, *.png means all files ending with .png. That is an illegal regex expression. For regex you need: .*\.png. Or to simplify: .*png which will find all files ending in png (not necessarily ending in an extension of png).

  • Regex is case sensitive by default. In most cases, use the case insensitive flag: (?i). See one of the examples below.

  • Dotall mode when you need to match across line breaks. 

Simple Examples



Advanced Examples

Value

Regex

Matches

Find

Demonstrates

Value

Regex

Matches

Find

Demonstrates

example.txt 

^((?!\.png).)*$

Find string not containing a word. In this example, files that do not have a .png extension

example.png 

^((?!\.png).)*$

Find string not containing a word. In this example, files that do not have a .png extension

example.jpeg

(?=^((?!\.png).)*$)(?=^((?!\.jpeg).)*$)

Find string not containing a word. In this example, files that do not have a .png or .jpeg extension

collateral wholesale retail

.*(?=.*\bretail\b.*)(?=.*\bcollateral\b.*).*



Match exact words anywhere in string. In this case a blank separated list of labels and we require both collateral and retail to be included before we want the match to be successful

wholesale retail

.*(?=.*\bretail\b.*)(?=.*\bcollateral\b.*).*



Both are required for a match

merger acquisition

.*\b(?:merger|acquisition)\b.*



Match string containing either word

Content with regex label

References