source: buchla-68k/orig/GEMDOS/DIRNOTES.TXT

Netters,

Here are some directory routines I put together awhile back for MS-DOS
which provide the same functionality as the 4.2 BSD directory routines.
In this kit you will find scandir(), opendir(), readdir(), seekdir(),
telldir(), closedir(), etc.  They behave like the 4.2 routines with some
minor exceptions:  The actual directory structure is different since
MS-DOS keeps the equivilent of directory entry and inode in its directory,
and a picture of the directory is read in during an opendir() call, so if
something changes in the directory it will not show up in readdir() calls,
unless you do another opendir().

These routines were written for Microsoft C, though the only special
functions I used were realloc() and intdos(), which most 'modern' C
compilers have.

I have also compiled these under all memory models with no problems.
Microsoft C automatically provides a #define for use in detecting
which memory model is in use.  I use this in scandir() to set up the
pointers correctly.  I also use the FP_SEG and FP_OFF macro's too.
Other C compilers will have to have this section changed to handle 
their method of splitting far pointers into segments and offsets.

Also included in this kit (Don't send your money now, there's more!)
are two simple test programs, test1.c and test2.c.  These programs
show how to do a simple directory search, with test1.c using opendir(),
and test2.c using scandir().  Test2.c also uses another function
called fmatch(), which I found on the net many months ago in a slightly
different form.  To compile the test programs, use:

        cl test1.c dir.obj scandir.obj
        cl test2.c fmatch.obj scandir.obj

after compiling dir.c, scandir.c, and fmatch.c.

If you have any comments or bug reports, send them to:

Bill Marsh, Naval Ocean Systems Center, San Diego, CA
{arpa,mil}net: bmarsh@nosc
uucp: {ihnp4,akgua,decvax,dcdwest,ucbvax}!sdcsvax!noscvax!bmarsh