Display the type of data in a file based on rules defined in the /usr/lib/magic file (this is known as the magic file).
file [options] files
-c displays a parsed form of a magic file (or the default one) and exits.
-m file1[:file2 : . . .] specifies other magic files.
-v displays the version number and exits.
-z looks inside compressed files.
The file command uses rules specified in the /usr/lib/magic file to determine the type of data in the specified files. For example, you can use the file command to check the type of each file in the /usr/lib directory, as shown here:
file * | more alchemist: directory ao: directory appletproxy.la: ASCII English text, with very long lines appletproxy.so: ELF 32-bit LSB shared object, Intel 80386, version 1 (SYSV), stripped aspell: directory autofs: directory bash: directory bcc: directory bonobo: directory bonobo-2.0: directory bonobo_confConf.sh: ASCII English text, with very long lines bonoboConf.sh: ASCII English text, with very long lines bonoboxConf.sh: ASCII English text, with very long lines bonobox_printConf.sh: ASCII English text, with very long lines cracklib_dict.hwm: data cracklib_dict.pwd: data cracklib_dict.pwi: data (. . . lines deleted)