To determine the file type in Linux, we can use the file command. This command runs three sets of tests: the filesystem test, magic number test, and language test. The first test that succeeds causes the file type to be printed. For example, if a file is a text file, it will be recognized as ASCII text.

How does Unix determine file type?

A file’s type can be identified by the ls -l command, which displays the type in the first character of the file-system permissions field. For regular files, Unix does not impose or provide any internal file structure; therefore, their structure and interpretation is entirely dependent on the software using them.

How does file determine file type?

file makes a guess at the type of each file argument by inspecting the attributes and (for an ordinary file) reading an initial part of the file. file compares each file on the command line to templates found in a system-maintained magic file to determine their file type.