Re: [Update REQ 6141]: Re: Connecting Geomview with another X-application

[daemon]

I just tried the following program under both geomview 1.5 and 1.6.1
on Solaris, and 1.6.1 on Irix, and it seemed to work fine.
Specifically, I see:

   "started geomview" message
	(geomview loads slowly over the network, no windows yet)
   "opened fromgv", "opened togv", "sent command"  nearly simultaneously
	(geomview windows appear, and respond to interaction.  I don't
	 even need to wait until reading something from the fromgv pipe.)
   "listening"

Clicking the right mouse button in the graphics window yields messages like

(pick World hdodec.off (-0.0031538 -0.18392 0.115354 0.391025) () () (0.224752 -0.462585 0.363661 1 -0.224756 -0.462585 0.363661 1 -0.363661 -0.510647 -0.0611362 1 0 -0.54035 -0.323677 1 0.363663 -0.510643 -0.0611362 1) () -1 () 4)


Here's the program.

#!/bin/sh
# This is a shell archive (shar 3.43)
# made 03/26/1997 22:33 UTC by slevy at hausdorff
# Source directory /usr6/slevy
#
# existing files will NOT be overwritten unless -c is specified
#
# This shar contains:
# length  mode       name
# ------ ---------- ------------------------------------------
#   1542 -rw-rw-r-- t.c
#
# ============= t.c ==============
if test -f 't.c' -a X"$1" != X"-c"; then
	echo 'x - skipping t.c (File already exists)'
else
echo 'x - extracting t.c (Text)'
sed 's/^X//' << 'SHAR_EOF' > 't.c' &&
#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
X
main() {
X  FILE *togv, *fromgv;
X  char line[200];
X
X  /* Ensure (more or less) that no one else is using these FIFOs */
X  unlink("/tmp/togv");
X  unlink("/tmp/fromgv");
X  mknod("/tmp/togv", S_IFIFO|0777, 0);
X  mknod("/tmp/fromgv", S_IFIFO|0777, 0);
X
X  /* Invoke geomview.  Use the "command" command, which takes a pair of
X   * file names; the first feeds commands to geomview, and the second
X   * receives responses from geomview.  Note that the FIFOs mentioned here
X   * must exist before we start geomview.
X   */
X  system("geomview -c '(command /tmp/togv /tmp/fromgv)' hdodec.off &");
X  printf("started geomview.\n");
X
X  /* UNIX FIFO semantics imply that this will block until geomview starts.
X   * If you don't entirely trust it to work, you might use
X   * open( "/tmp/togv", O_WRONLY|O_NONBLOCK ) and a polling loop
X   * that waited a few seconds for geomview to start, gave up if it didn't,
X   * and otherwise used fdopen() to get a FILE pointer.
X   * But this should work if all's well.
X   */
X  fromgv = fopen("/tmp/fromgv", "r");
X  printf("opened fromgv.\n");
X
X  togv = fopen("/tmp/togv", "w");
X  printf("opened togv.\n");
X
X  fprintf(togv, "(interest (pick world))\n");
X  printf("sent command.\n");
X  fflush(togv);
X  sleep(5);	/* I think geomview should start immediately, but
X		 * let's see whether it waits until we actually
X		 * read from the fromgv pipe.
X		 */
X  printf("listening.\n");
X  while(fgets(line, sizeof(line), fromgv) != NULL) {
X	fputs(line, stdout);
X  }
}
SHAR_EOF
chmod 0664 t.c ||
echo 'restore of t.c failed'
Wc_c="`wc -c < 't.c'`"
test 1542 -eq "$Wc_c" ||
	echo 't.c: original size 1542, current size' "$Wc_c"
fi
exit 0