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From: BITNET@UTHSCSA.BITNET.UUCP
Newsgroups: mod.computers.vax
Subject: Direct input in C on vax
Message-ID: <8703010449.AA20447@ucbvax.Berkeley.EDU>
Date: Sat, 28-Feb-87 23:49:46 EST
Article-I.D.: ucbvax.8703010449.AA20447
Posted: Sat Feb 28 23:49:46 1987
Date-Received: Sun, 1-Mar-87 17:15:47 EST
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Subject: Direct input in C on vax

>     I cannot find a way to directly read input from the keyboard, character
>by character.  The routines I know of in C all require the user to hit <return>
>at the end of the line to signal to the computer that input is done.  If there
>is some way around this, I would greatly appreciate it.


In this particular test program I was trying to read a delete character.
It should at least get you started.  In this test program I didn't deassign
the channel.  I don't have a system services manual here at home, and I
don't remember the exact call.  I think it is $deassign(channel), but
I can't swear to it.

Mark Moore
Moore@UTHSCSA
The University of Texas
Health Science Center
San Antonio, Texas 78284

-------------------------------------------------------------------------------
# include <iodef.h>
# include <descrip.h>

main()
{
   int         i;             /* used to index loop                     */
   char        keypress;      /* store character returned from termread */
   short int   channel;       /* get term chan from $assign             */

   termchan(&channel);

   i = 20;
   do
   {

       termread(&channel,&keypress);
       printf("keypress = %c\n",keypress);
       if (keypress == 27 )
       {
         printf("that was an escape\n");
       }
       if (keypress == 127 )
       {
         printf("that was most definitely a delete\n");
       }
       i--;

   } while (i);

}

termchan(channel)

short int *channel;               /* must be a word.  It won't work if    */
                                  /* you make it a long word.             */

{
   int     stat;                  /* store return status from sys calls   */
   char    term[20] = "                  ";


   $DESCRIPTOR(dst,term);

   ctermid(term);

   stat = sys$assign(&dst,channel, 0, 0);


}

termread(channel,buffer)

short int *channel;
char    *buffer;                /* buffer for characters                   */

{

   int    length;                 /* length of buffer                        */
   int    stat;                   /* store return status form sys calls      */

   length=1;
   stat = sys$qiow(0,                                        /* event flag */
                   *channel,                                 /* channel    */
                   IO$_READVBLK+IO$M_NOECHO+IO$M_NOFILTR,    /* function   */
                   0,                                        /* iosb       */
                   0,                                        /* astadr     */
                   0,                                        /* astprm     */
                   buffer,                                   /* p1         */
                   length,                                   /* p2         */
                   0,                                        /* p3         */
                   0,                                        /* p4         */
                   0,                                        /* p5         */
                   0);                                       /* p6         */

}