This program tests the ioctl.c example file systsem.
Compile with:
gcc -Wall ioctl_client.c -o ioctl_client
Source code
#include <sys/types.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <sys/ioctl.h>
#include <stdio.h>
#include <stdlib.h>
#include <ctype.h>
#include <errno.h>
#include <unistd.h>
const char *usage =
"Usage: fioclient FIOC_FILE [size]\n"
"\n"
"Get size if <size> is omitted, set size otherwise\n"
"\n";
int main(int argc, char **argv)
{
size_t size;
int fd;
int ret = 0;
if (argc < 2) {
fprintf(stderr, "%s", usage);
return 1;
}
fd = open(argv[1], O_RDWR);
if (fd < 0) {
perror("open");
return 1;
}
if (argc == 2) {
if (ioctl(fd, FIOC_GET_SIZE, &size)) {
perror("ioctl");
ret = 1;
goto out;
}
printf("%zu\n", size);
} else {
size = strtoul(argv[2], NULL, 0);
if (ioctl(fd, FIOC_SET_SIZE, &size)) {
perror("ioctl");
ret = 1;
goto out;
}
}
out:
close(fd);
return ret;
}
Definition in file ioctl_client.c.