On filesystem error, issues an error message and exits.Įxcludes a test from the list of tests performed on a file.Įxcludes tests that the file command doesn't know about. Prints internal debugging information in the standard error format. The file command uses the following options: OptionĬhanges the command output to the one used by older versions of MacOS.Ĭreates an output file that contains a pre-parsed version of the magic file or directory.Ĭhecks the printout for the parsed version of the magic file. For instance, using the file command to test a text file: file example.txt The command output provides a short description of the file and data type. Language tests use a special tag to determine which programming language a binary executable file is written in.The information needed to perform these tests is stored in /etc/magic or /usr/share/misc/magic from a compiled magic file. Magic tests use a short string of numbers stored near the beginning of the file ('magic number') to test if the file is a binary executable and, if so, determine its type.This way, the file command determines if the file is a common type for your system (such as a text file, image, directory, etc.).

Filesystem tests perform a stat(2) system call and check the result against the system header file.

The file command performs three sets of tests trying to determine the file type, in this order: In the syntax above, file name represents the name of the file you want to test. The file command uses the following basic syntax: file

How to view file types in mac