file(1) [ultrix man page]
file(1) General Commands Manual file(1) Name file - determine file type Syntax file [ -c ] [ -f ffile] [ -m mfile] filename ... Description The command performs a series of tests on each filename argument in an attempt to classify it. If an argument appears to be ASCII, the command examines the first 1024 bytes and tries to guess its language. For character special files, part of this classification is information about which devices the system shows as active. In particular, device-specific information such as controller type and unit, device type and unit, and status (offline, write locked, density, errors) is returned. The general categories currently implemented are disk, tape, and terminal devices. The supported terminal devices include Local Area Terminals (LAT) but not Local Area Network (LAN) pseudo-terminals. The command uses the file to identify files that have some sort of magic number. A magic number is any numeric or string constant that identifies the file containing the constant. Commentary at the beginning of explains its format. Options -c Checks the magic file for format errors by printing the internal representation of the magic file. No file typing is done under -c. -f Interprets the following argument to be a file containing the names of the files to be examined. -m Instructs file to use an alternate magic file. Restrictions It often does a poor job of distinguishing C programs, shell scripts, English text, and ASCII text. It does not recognize many programming languages, including Modula, Pascal, and Lisp. Files /usr/lib/file/magic See Also magic(5) file(1)
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file(1B) SunOS/BSD Compatibility Package Commands file(1B) NAME
file - determine the type of a file by examining its contents SYNOPSIS
/usr/ucb/file [-f ffile] [-cL] [-m mfile] filename... DESCRIPTION
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 con- stant that indicates its type. OPTIONS
-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. EXAMPLES
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% ENVIRONMENT VARIABLES
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 environ- ment 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. FILES
/etc/magic ATTRIBUTES
See attributes(5) for descriptions of the following attributes: +-----------------------------+-----------------------------+ | ATTRIBUTE TYPE | ATTRIBUTE VALUE | +-----------------------------+-----------------------------+ |Availability |SUNWscpu | +-----------------------------+-----------------------------+ SEE ALSO
magic(4), attributes(5) BUGS
file often makes mistakes. In particular, it often suggests that command files are C programs. file does not recognize Pascal or LISP. SunOS 5.10 14 Sep 1992 file(1B)