Regular expressions is a special language for searching text and manipulating substrings, based on the use of wildcard characters from which a search pattern is built.
This Regular expression search in PDF app only searches for single words in text using a given pattern. Phrase search and boolean search are not supported. However, the full-text search engine GroupDocs.Search, on which this application is based, also supports phrase search and boolean search in PDF when forming a query in object form. In this case, search patterns are specified separately for each word.
A regular expression example is the following string: "(.)\1{1,}". This query searches for a word that includes two consecutive identical characters. Note that the quotes around the expression are not part of the query. For this query, for example, the following words will be found:
This application is based on the .NET C# library, so use the regular expression language reference for the .NET C# language as needed.
You can also perform regular expressions search in many other file formats. Please see the full list below.