SRTDIR31
                Alpha One Micro-Consulting, Ltd.

Modified by:   Don A. Williams  November 24,1984
               Arizona Kaypro Users' Group (AKUG)



SRTDIR  was  originally SORTDIR included in the NEWARC.LBR  file.  
It  appears to be another program by Dave Rand although his  name 
does not appear anywhere in the program.  The only identification 
in the program is the "Alpha One Micro-Consulting,  Ltd." byline.  
The program,  like all of those in NEWARC.LBR, does not appear to 
be  copyrighted  since  there is no copyright  statement  in  the 
object  code.   The  name  was changed to  SRTDIR  to  allow  for 
inclusion of a version and release code;  the original version in 
NEWARC was Version 3.0 so I called this minor revision 3.1.

SRTDIR is a functional replacement for SAP and performs the  same 
basic functions; i.e. it sorts a directory in to alphabetic order 
and writes it back out to the disk.   This sorting not only makes 
the  directory  easier to handle with facilities such as  DU  and 
DIR,  but,  since  it collects all of the extents of large  files 
into a contiguous area in the directory,  makes handling of these 
larger files by almost any facility considerably faster.

SRTDIR  also provides some useful statistics on disk  utilization 
that I like.

The  original  SORTDIR required specification of the disk  to  be 
processed and did nothing more than sort the directory.  SRTDIR31 
will  process the current disk if none is specified and  provides 
the  option  of eliminating erased files from the  directory  for 
security.  I frequently make copies of disks for other people and 
these   copies  might  contain  erased  versions  of  proprietary 
programs or other programs that I do not want to put into general 
circulation.   Purging  the  directory entries for  erased  files 
(filling the entry with E5Hs) makes recovery of these erased file 
difficult for even the most persistent 'hacker'.

Use  of SRTDIR is simple.   If you wish to sort the directory  of 
the current disk:

     A>SRTDIR

will  do the job ('A>' stands for CP/M's normal  prompt  and,  in 
this example, indicates that disk A is the current disk.)

If  you  wish to sort the directory of some disk other  than  the 
current  disk,  simply indicate the disk that you wish to sort on 
the SRTDIR command line in the usual CP/M fashion as follows:

     A>SRTDIR B:

This example would sort the directory of the disk on drive B even 
though  the current disk is A.   SRTDIR will NOT reset  the  disk 
drives  so be sure to do a Control-C before using it if you  have 
changed  disks.   It does return to CP/M with a Warm Boot so that 
the disks will not be Read Only when it is through.

The distributed version of SRTDIR3.1 is set to purge erased files 
by  default.   This  operation can be modified in either  of  two 
ways.   At  location 103H in SRTDIR is a byte that  controls  the 
action  to be taken for erased files.   If this byte is zero,  no 
action will be taken; i.e. the files will remain in the directory 
as erased.   If this byte is non-zero (usually 0FFH,) the entries 
for  all  erased files will be purged (filled  with  0E5Hs.)   To 
change the default action of SRTDIR, uses DDT, SID, ZSID, etc. to 
change the contents of the byte at 103H.

To  override  the  default action of SRTDIR for  occasional  use, 
SRTDIR provides a Command Line option as follows:

     A>SRTDIR B:$E

The  $E switch on the command line will REVERSE the operation  of 
the default setting.  In the distributed version of SRTDIR31, the 
previous  command will NOT purge the erased files.   If you  have 
changed  the  byte  at 103H in SRTDIR to a zero  (default  to  no 
purge,)  the previous command would cause the erased files to  be 
purged.

Since Dave Rand did not release the source for SORTDIR,  I do not 
feel that I can release the source for SRTDIR.  However, since it 
is  a small,  clean program,  it can be disassembled using any of 
the Christensen disassemblers (RESOURCE, ZSOURCE, ZDASM, etc.) in 
relatively  short time.   My source for SRTDIR was obtained  this 
way using a very old version of RESOURCE.

Possible  future  revisions  of this  program  would  include  an 
optional  facility to purge zero length files (with the  optional 
exception of those beginning with a '-';  the usual indication of 
a volume label for the cataloging systems.)


Don A. Williams
Arizona Kaypro Users' Group (AKUG)