MS-DOS passwd library
			       Stephen C. Trier

     In the process of porting UNIX software to MS-DOS, especially news and
mail packages, I've run into a need for the UNIX-style password file
functions.  This time I couldn't find a different way out, so I whipped up
these functions.  They aren't secure, and they aren't intended to be.  Instead,
they are meant to access the second function of the UNIX passwd file, which is
to contain information about various users.  This they should do well.  Please
note again: THESE FUNCTIONS ARE NOT INTENDED TO BE USED TO PROVIDE SECURITY TO
AN MS-DOS SYSTEM.  However, they _are_ intended to simplify the task of porting
UNIX applications to the MS-DOS environment.

     The most significant difference between these functions and the UNIX
version is the format of the /etc/passwd file.  Because home directory
specifications should really include a drive letter, and the drive name
requires a colon, these routines expect the file to have its fields separated
by semicolons.  This should not change the functionality of these routines,
because the delimiter is never seen by the application program.

     Where will the password file be found?  The library looks for a shell
variable named PASSWD to determine the location of the file.  If that variable
has not been defined, the library uses a UNIX-style path of /etc/passwd.  Your
program can override these choices, however, by calling the function pw_open()
with a filename as an argument.  Calling pw_open with NULL as the argument
tells it to use the shell-variable and default name to find the file.

     I cannot guarantee that these functions are a wonderfully exact clone of
the UNIX versions; there may even be some big differences.  This is because I
have no real documentation available about the UNIX versions.  However, that
also means that I am free to place my version in the public domain.  Use it as
you wish, and I would be quite interested in hearing of any changes or
improvements you make.

     There is a simple makefile included, but it is not capable of building
more than one library at a time.  That's a bit beyond my makefile-writing
ability, so if you want a fully-automated, whiz-bang makefile, you'll have to
write it yourself.  (I'd be rather interested in such a beast, to tell the
truth.)

     Hope these are useful to you.

	      Stephen



How to reach me by email:
   sct%seldon@scl.cwru.edu will work until May 1990, and (maybe) later.
   sct@po.cwru.edu will work throughout the scholastic year.
   sct@seldon.UUCP will work once I find another feed and get a map entry.

Sample output from the test program:

---------- cut here ----------
Name: user1  Password: password1  User Num: 1  Group Num: 11
Full Name: Joe User  Home Dir: \homes\user1  Shell: sh1

Name: user2  Password: password2  User Num: 2  Group Num: 12
Full Name: Joe User Jr.  Home Dir: \homes\user2  Shell: sh2

Name: user3  Password: password3  User Num: 3  Group Num: 13
Full Name: Joe User III  Home Dir: \homes\user3  Shell: sh3

setpwent returns 0
Name: user1  Password: password1  User Num: 1  Group Num: 11
Full Name: Joe User  Home Dir: \homes\user1  Shell: sh1

Name: user2  Password: password2  User Num: 2  Group Num: 12
Full Name: Joe User Jr.  Home Dir: \homes\user2  Shell: sh2

Name: user3  Password: password3  User Num: 3  Group Num: 13
Full Name: Joe User III  Home Dir: \homes\user3  Shell: sh3

setpwent returns 0
Finding user3: user3
Finding user1: user1
Finding user2: user2
Finding user4: NULL  (Should be NULL)

Finding user id 2: user2
Finding user id 1: user1
Finding user id 3: user3
Finding user id 4: NULL  (Should be NULL)

endpwent returns 0
--------- cut here ---------

Remember that in order to get this output, one of the following must be true:
(1) the included "passwd" file is in \etc\passwd, or (2) the $PASSWD
environment variable must point to its location.  (set PASSWD=passwd is
probably sufficient for testing purposes.)