This is the readme file for the port to OS/2 1.x--2.x and DOS of 
Ian Darwin's file(1) command.  The UNIX program attempts to determine 
the type of file based on the contents. A database of signatures 
(the magic(4) file) is used.

Excerpted from the man-page:

  File tests each argument in an  attempt  to  classify  it.
  There  are  three  sets of tests, performed in this order:
  filesystem tests, magic number tests, and language  tests.
  The  first  test  that succeeds causes the file type to be
  printed.


Example:

 [c:\tmp]file *
 bin:         directory
 file.1:      troff or preprocessor input text
 file39a.zip: Zip archive (at least v2.0 to extract)
 textfile:    English text
 pencils.gif: GIF picture version 87a 800 x 800, interlaced, 256 colors
 tarfile:     tar archive
 tarfile.Z:   block compressed data - 16 bits


Darwin's version has several enhancements over the usual UNIX versions,
including:
 1. More flexible magicfile entries.

 2. An "ascii magic" routine for keywords which can appear anywhere in 
    the file.

 3. "-z" option will recursively unwind compress'd files to determine
    the types.

This OS/2 port has an additional enhancement:
 4. DosQ[uery]AppType is used to determine the type (DOS, OS/2, 32-bit,
    etc.) of an executable or DLL.

QUICK START: This archive contains only the DOS executable; see
src/Where to find locations for OS/2 executables and sources.
Copy the file "magic" to one of the following locations:
 * /etc/
 * directory of the exectable
 * a directory in PATH or DPATH
or use the command-line option "-m" to specify the magicfile location.

Now try:
 file *      or      file *.*


Notes:
1. file v3 patchlevel9 is by Ian Darwin (darwin@cs.toronto.edu); see
the README file. This is the second release of the OS/2 version. Many
thanks to Greg Roelofs (newt@uchicago.edu) for the help.

2. The magicfile needs more work. There are some other suggestions in
notes*.os2. Thanks to Jouni Miettunen (jon@stekt.oulu.fi) for the
contributions. Darwin collects magicfile entries.

3. See the files notes*.os2 for additional information on the OS/2 and
DOS ports. This is the first port to OS/2 and DOS; feedback and
magic-file entries are welcomed.

4. The *.man files are formatted by "groff -man"; as such, they are
intended to be read with the "less" pager. This pager is available at
  oak.oakland.edu:/pub/msdos/txtutl/less177e.zip

--
Darrel Hankerson  hankedr@mail.auburn.edu  or  hank@ducvax.auburn.edu
11-Apr-93, updated 30-Jul-93

OS/2 version 3.9 to 3.9a updates:

Fixes: correct display of date info (e.g., on gzip'd files); fix
message on OS/2 exe's with no application type; correct code
which could cause trouble with the "-c" option on bad input. 
Additions and corrections to the magic-file.

Changes: In OS/2 versions, continue on to the magic-file checks
in the case that DosQueryApptype indicates a DOS executable. This 
permits use of the checks for special (e.g., compressed) executables.