TRID is a utility created to identify common file types from their binary codes. Since this is open-source software, it is freely available as a suite in which to run both TrID decompression software and TrID recovery software. Just unpack both TrID and this library and place them in the same directory. The database of known extensions is continuously expanding; therefore, an improved search of an unknown file will be an easy job if available extensions are present.
In simple words, TrID uses algorithms that break file types into segments with specific extensions and then identifies the segment based on its content. It does this by scanning each extension found and determining the meaning of the left or right parenthesis. When a matching segment is found, the matching content is also identified. This technique provides good quality identification for most common file formats.
Some other open source technologies such as LZH, LZO, and Zipeg are also used as reference. They work on different identification algorithm that takes care of different file extension identification problems. Among others, LZH and Zipeg provide the required extension match using lexical rules. LZH and Zipeg also have some additional features such as fuzzy matching to detect unknown file extensions. But still, these programs do not support all file extensions and are not developed as extensively as TrID.