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 page has a few simple examples to get started. Use the references for more advanced information. We recommend testing your regular expressions in one of the well-known regex testing sites such as 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.
- 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.
In dotall mode, the expression . matches any character, including a line terminator. By default this expression does not match line terminators. Dotall mode can also be enabled via the embedded flag expression (?s). (The s is a mnemonic for "single-line" mode, which is what this is called in Perl.)