#include #include #include #include #define IOCTL_TEST _IOW(0, 6, struct ioctl_test_t) int main () { /* attribute structures */ struct ioctl_test_t { int field1; char field2; } ioctl_test; int fd = open ("/proc/ioctl_test", O_RDONLY); ioctl_test.field1 = 10; ioctl_test.field2 = 'a'; ioctl (fd, IOCTL_TEST, &ioctl_test); /* test read() */ char buf[100]; read(fd, buf, 100); printf("read %s\n", buf); return 0; }