/usr/ucb/file [-f ffile] [-cL] [-m mfile] filename...
file performs a series of tests on each filename in an attempt to determine what it contains. If the contents of a file appear to be ASCII text, file examines the first 512 bytes and tries to guess its language.
file uses the file /etc/magic to identify files that have some sort of magic number, that is, any file containing a numeric or string constant that indicates its type.
-c Check for format errors in the magic number file. For reasons of efficiency, this validation is not normally carried out. No file type-checking is done under -c.
-f ffile Get a list of filenames to identify from ffile.
-L If a file is a symbolic link, test the file the link references rather than the link itself.
-m mfile Use mfile as the name of an alternate magic number file.
Example 1: Using file on all the files in a specific user's directory.
This example illustrates the use of file on all the files in a specific user's directory:
example% pwd /usr/blort/misc
example% /usr/ucb/file * code: mc68020 demand paged executable code.c: c program text counts: ascii text doc: roff,nroff, or eqn input text empty.file: empty libz: archive random library memos: directory project: symboliclink to /usr/project script: executable shell script titles: ascii text s5.stuff: cpio archive example%
The environment variables LC_CTYPE, LANG, and LC_default control the character classification throughout file. On entry to file, these environment variables are checked in the following order: LC_CTYPE, LANG, and LC_default. When a valid value is found, remaining environment variables for character classification are ignored. For example, a new setting for LANG does not override the current valid character classification rules of LC_CTYPE. When none of the values is valid, the shell character classification defaults to the POSIX.1 "C" locale.
See attributes(5) for descriptions of the following attributes:
|ATTRIBUTE TYPE||ATTRIBUTE VALUE|
file often makes mistakes. In particular, it often suggests that command files are C programs.
file does not recognize Pascal or LISP.