A filter field helps you to quickly reduce the number of items displayed in a list. This makes it much easier to find the object(s) you were looking for.
- A search in a list typically scans several fields for the search expression. A search in Users & Groups for example considers the username, the real name, the comment, and the first email address. Generally speaking, the search considers all texts which you can see in the list, excluding details displayed via the Info icon.
The list search is case-insensitive. That means it makes no difference whether you enter upper- or lower-case letters. The search result will contain matches both with upper-case and lower-case letters. Searching explicitly for upper-case or lower-case letters is not possible.
- The list search is based on Perl regular expression syntax (although case-insensitive). Typical search expressions known from e.g. text editors like * and ? as simple wildcard characters or the AND and OR operators do not work in list search.
The following list is a small selection of useful search strings:
Simple string: Matches all words that contain the given string. For example, "inter" matches "Internet", "interface", and "printer".
Beginning of a word: Mark the search expression with a \b at the beginning. For example, \binter matches "Internet" and "interface" but not "printer".
End of a word: Mark the search expression with a \b at the end. For example, http\b matches "http" but not "https".
Beginning of an entry: Mark the search expression with a ^ at the beginning. For example, ^inter matches "Internet Uplink" but not "Uplink Interfaces".
IP addresses: Searching for IP addresses, you need to escape dots with a backslash. For example, 192\.168 matches "192.168". To search more generally for IP addresses use \d which matches any digit. \d+ matches multiple digits in a row. For example, \d+\.\d+\.\d+\.\d+ matches any IPv4 address.
Note – It makes sense to rather use an easy, fail-safe search expression which will lead to more matches than to rack your brains for a supposedly more perfect one which can easily lead to unexpected results and wrong conclusions.
You can find a detailed description of regular expressions and their usage in Sophos UTM on AWS in the Sophos Knowledge Base.