Hi,
This has to be something really simple but I'm hitting a wall. I have a
rt module that creates a pipe and periodically writes some data to it.
In the following program, the read fails with "No space left on device":
int main (void) {
int r, fd; u_char c;
fd = open("/proc/xenomai/registry/pipes/rt2event", O_RDWR);
if (fd < 0) {
fprintf(stderr, "ERROR opening pipe: %s\n", strerror(errno));
return -1;
}
for (;;) {
r = read(fd, &c, sizeof(c));
if (r == 0) { fprintf(stderr, "ERROR reading (returned 0)\n");
break; }
if (r < 0) { fprintf(stderr, "ERROR reading: %s\n",
strerror(errno)); break; }
fprintf(stderr, "%02hX ", c);
}
close(fd);
return 0;
}
However, the following program works fine!!!
int main (void) {
int r; u_char c;
FILE *f;
f = fopen("/proc/xenomai/registry/pipes/rt2event", "r+b");
if (f == NULL) {
fprintf(stderr, "ERROR opening pipe: %s\n", strerror(errno));
return -1;
}
for (;;) {
r = fread(&c, sizeof(c), 1, f);
if (r == 0) { fprintf(stderr, "ERROR reading (returned 0)\n");
break; }
if (r < 0) { fprintf(stderr, "ERROR reading: %s\n",
strerror(errno)); break; }
fprintf(stderr, "%02hX ", c);
}
fclose(f);
return 0;
}
Any clues?
By the way, I noticed a "cat /proc/xenomai/registry/pipes/rt2event |
xxd" won't work, perhaps due to the same reason?
_______________________________________________
Xenomai-help mailing list
[email protected]
https://mail.gna.org/listinfo/xenomai-help
