/* * Test program to try to query device id from printer. */ #include #include #include #include #include #include #include #include #include #include #define IOCNR_GET_DEVICE_ID 1 #define LPIOC_GET_DEVICE_ID(len) \ _IOC(_IOC_READ, 'P', IOCNR_GET_DEVICE_ID, len) // get device_id string #define LPGETSTATUS 0x060b // drivers/char/lp.c int error(int fatal, char *fmt, ...) { va_list ap; fprintf(stderr, fatal ? "Error: " : "Warning: "); if (errno) fprintf(stderr, "%s: ", strerror(errno)); va_start(ap, fmt); vfprintf(stderr, fmt, ap); va_end(ap); if (fatal > 0) exit(fatal); else { errno = 0; return (fatal); } } int main (int argc, char *argv[]) { int fd; unsigned char argp[1024]; int length; --argc; ++argv; if (argc != 1) error(1, "usage: usb_id_test /dev/usb/lp0\n"); fd = open(argv[0], O_RDWR); if (fd < 0) error(1, "can't open '%s'\n", argv[0]); if (ioctl(fd, LPIOC_GET_DEVICE_ID(sizeof(argp)), argp) < 0) error(1, "GET_DEVICE_ID on '%s'\n", argv[0]); length = (argp[0] << 8) + argp[1] - 2; printf("GET_DEVICE_ID string:\n"); fwrite(argp + 2, 1, length, stdout); printf("\n"); #if 0 if (ioctl(fd, LPGETSTATUS, &status) < 0) error(1, "LPGETSTATUS on '%s'\n", argv[0]); printf("Status: 0x%02x\n", status); #endif close(fd); exit(0); }