You can configure the text pattern exclusion in a regular expression using Perl Compatible Regular Expressions (PCRE). The PCRE library enables the execution of regular expression pattern matching. PCRE library provides the flexibility to specify a pattern to be included or excluded in a regular expression during pattern matching.
In some search criteria, you may need to match a text pattern (in a log file) only if a specific text pattern is excluded. You can exclude a text pattern by creating a unique regular expression and identifying the expression with the excluded pattern. For instance, you can create an expression to identify matches only for substrings with ‘abc’, excluding ‘def’. To exclude 'def' in a regular expression, use negative assertion to not to match if subject contains substring 'def'.
Example: Configure Text Pattern Exclusion
The following example specifies the search option to search for text pattern that matches all strings ‘abc_’, which is not followed by string ‘def’. Here, the brackets () is used to group the strings and ?! represents negation.
abc_(?!def)
|
Copyright © 2013 CA.
All rights reserved.
|
|