| #include <stdio.h> |
| #include <stdlib.h> |
| #include <fcntl.h> |
| #include <unistd.h> |
| #include <string.h> |
| #include <sys/poll.h> |
| #include <sys/ioctl.h> |
| #include <linux/usb/g_printer.h> |
| |
| #define PRINTER_FILE "/dev/g_printer0" |
| #define BUF_SIZE 512 |
| |
| |
| /* |
| * 'usage()' - Show program usage. |
| */ |
| |
| static void |
| usage(const char *option) /* I - Option string or NULL */ |
| { |
| if (option) { |
| fprintf(stderr,"prn_example: Unknown option \"%s\"!\n", |
| option); |
| } |
| |
| fputs("\n", stderr); |
| fputs("Usage: prn_example -[options]\n", stderr); |
| fputs("Options:\n", stderr); |
| fputs("\n", stderr); |
| fputs("-get_status Get the current printer status.\n", stderr); |
| fputs("-selected Set the selected status to selected.\n", stderr); |
| fputs("-not_selected Set the selected status to NOT selected.\n", |
| stderr); |
| fputs("-error Set the error status to error.\n", stderr); |
| fputs("-no_error Set the error status to NO error.\n", stderr); |
| fputs("-paper_out Set the paper status to paper out.\n", stderr); |
| fputs("-paper_loaded Set the paper status to paper loaded.\n", |
| stderr); |
| fputs("-read_data Read printer data from driver.\n", stderr); |
| fputs("-write_data Write printer sata to driver.\n", stderr); |
| fputs("-NB_read_data (Non-Blocking) Read printer data from driver.\n", |
| stderr); |
| fputs("\n\n", stderr); |
| |
| exit(1); |
| } |
| |
| |
| static int |
| read_printer_data() |
| { |
| struct pollfd fd[1]; |
| |
| /* Open device file for printer gadget. */ |
| fd[0].fd = open(PRINTER_FILE, O_RDWR); |
| if (fd[0].fd < 0) { |
| printf("Error %d opening %s\n", fd[0].fd, PRINTER_FILE); |
| close(fd[0].fd); |
| return(-1); |
| } |
| |
| fd[0].events = POLLIN | POLLRDNORM; |
| |
| while (1) { |
| static char buf[BUF_SIZE]; |
| int bytes_read; |
| int retval; |
| |
| /* Wait for up to 1 second for data. */ |
| retval = poll(fd, 1, 1000); |
| |
| if (retval && (fd[0].revents & POLLRDNORM)) { |
| |
| /* Read data from printer gadget driver. */ |
| bytes_read = read(fd[0].fd, buf, BUF_SIZE); |
| |
| if (bytes_read < 0) { |
| printf("Error %d reading from %s\n", |
| fd[0].fd, PRINTER_FILE); |
| close(fd[0].fd); |
| return(-1); |
| } else if (bytes_read > 0) { |
| /* Write data to standard OUTPUT (stdout). */ |
| fwrite(buf, 1, bytes_read, stdout); |
| fflush(stdout); |
| } |
| |
| } |
| |
| } |
| |
| /* Close the device file. */ |
| close(fd[0].fd); |
| |
| return 0; |
| } |
| |
| |
| static int |
| write_printer_data() |
| { |
| struct pollfd fd[1]; |
| |
| /* Open device file for printer gadget. */ |
| fd[0].fd = open (PRINTER_FILE, O_RDWR); |
| if (fd[0].fd < 0) { |
| printf("Error %d opening %s\n", fd[0].fd, PRINTER_FILE); |
| close(fd[0].fd); |
| return(-1); |
| } |
| |
| fd[0].events = POLLOUT | POLLWRNORM; |
| |
| while (1) { |
| int retval; |
| static char buf[BUF_SIZE]; |
| /* Read data from standard INPUT (stdin). */ |
| int bytes_read = fread(buf, 1, BUF_SIZE, stdin); |
| |
| if (!bytes_read) { |
| break; |
| } |
| |
| while (bytes_read) { |
| |
| /* Wait for up to 1 second to sent data. */ |
| retval = poll(fd, 1, 1000); |
| |
| /* Write data to printer gadget driver. */ |
| if (retval && (fd[0].revents & POLLWRNORM)) { |
| retval = write(fd[0].fd, buf, bytes_read); |
| if (retval < 0) { |
| printf("Error %d writing to %s\n", |
| fd[0].fd, |
| PRINTER_FILE); |
| close(fd[0].fd); |
| return(-1); |
| } else { |
| bytes_read -= retval; |
| } |
| |
| } |
| |
| } |
| |
| } |
| |
| /* Wait until the data has been sent. */ |
| fsync(fd[0].fd); |
| |
| /* Close the device file. */ |
| close(fd[0].fd); |
| |
| return 0; |
| } |
| |
| |
| static int |
| read_NB_printer_data() |
| { |
| int fd; |
| static char buf[BUF_SIZE]; |
| int bytes_read; |
| |
| /* Open device file for printer gadget. */ |
| fd = open(PRINTER_FILE, O_RDWR|O_NONBLOCK); |
| if (fd < 0) { |
| printf("Error %d opening %s\n", fd, PRINTER_FILE); |
| close(fd); |
| return(-1); |
| } |
| |
| while (1) { |
| /* Read data from printer gadget driver. */ |
| bytes_read = read(fd, buf, BUF_SIZE); |
| if (bytes_read <= 0) { |
| break; |
| } |
| |
| /* Write data to standard OUTPUT (stdout). */ |
| fwrite(buf, 1, bytes_read, stdout); |
| fflush(stdout); |
| } |
| |
| /* Close the device file. */ |
| close(fd); |
| |
| return 0; |
| } |
| |
| |
| static int |
| get_printer_status() |
| { |
| int retval; |
| int fd; |
| |
| /* Open device file for printer gadget. */ |
| fd = open(PRINTER_FILE, O_RDWR); |
| if (fd < 0) { |
| printf("Error %d opening %s\n", fd, PRINTER_FILE); |
| close(fd); |
| return(-1); |
| } |
| |
| /* Make the IOCTL call. */ |
| retval = ioctl(fd, GADGET_GET_PRINTER_STATUS); |
| if (retval < 0) { |
| fprintf(stderr, "ERROR: Failed to set printer status\n"); |
| return(-1); |
| } |
| |
| /* Close the device file. */ |
| close(fd); |
| |
| return(retval); |
| } |
| |
| |
| static int |
| set_printer_status(unsigned char buf, int clear_printer_status_bit) |
| { |
| int retval; |
| int fd; |
| |
| retval = get_printer_status(); |
| if (retval < 0) { |
| fprintf(stderr, "ERROR: Failed to get printer status\n"); |
| return(-1); |
| } |
| |
| /* Open device file for printer gadget. */ |
| fd = open(PRINTER_FILE, O_RDWR); |
| |
| if (fd < 0) { |
| printf("Error %d opening %s\n", fd, PRINTER_FILE); |
| close(fd); |
| return(-1); |
| } |
| |
| if (clear_printer_status_bit) { |
| retval &= ~buf; |
| } else { |
| retval |= buf; |
| } |
| |
| /* Make the IOCTL call. */ |
| if (ioctl(fd, GADGET_SET_PRINTER_STATUS, (unsigned char)retval)) { |
| fprintf(stderr, "ERROR: Failed to set printer status\n"); |
| return(-1); |
| } |
| |
| /* Close the device file. */ |
| close(fd); |
| |
| return 0; |
| } |
| |
| |
| static int |
| display_printer_status() |
| { |
| char printer_status; |
| |
| printer_status = get_printer_status(); |
| if (printer_status < 0) { |
| fprintf(stderr, "ERROR: Failed to get printer status\n"); |
| return(-1); |
| } |
| |
| printf("Printer status is:\n"); |
| if (printer_status & PRINTER_SELECTED) { |
| printf(" Printer is Selected\n"); |
| } else { |
| printf(" Printer is NOT Selected\n"); |
| } |
| if (printer_status & PRINTER_PAPER_EMPTY) { |
| printf(" Paper is Out\n"); |
| } else { |
| printf(" Paper is Loaded\n"); |
| } |
| if (printer_status & PRINTER_NOT_ERROR) { |
| printf(" Printer OK\n"); |
| } else { |
| printf(" Printer ERROR\n"); |
| } |
| |
| return(0); |
| } |
| |
| |
| int |
| main(int argc, char *argv[]) |
| { |
| int i; /* Looping var */ |
| int retval = 0; |
| |
| /* No Args */ |
| if (argc == 1) { |
| usage(0); |
| exit(0); |
| } |
| |
| for (i = 1; i < argc && !retval; i ++) { |
| |
| if (argv[i][0] != '-') { |
| continue; |
| } |
| |
| if (!strcmp(argv[i], "-get_status")) { |
| if (display_printer_status()) { |
| retval = 1; |
| } |
| |
| } else if (!strcmp(argv[i], "-paper_loaded")) { |
| if (set_printer_status(PRINTER_PAPER_EMPTY, 1)) { |
| retval = 1; |
| } |
| |
| } else if (!strcmp(argv[i], "-paper_out")) { |
| if (set_printer_status(PRINTER_PAPER_EMPTY, 0)) { |
| retval = 1; |
| } |
| |
| } else if (!strcmp(argv[i], "-selected")) { |
| if (set_printer_status(PRINTER_SELECTED, 0)) { |
| retval = 1; |
| } |
| |
| } else if (!strcmp(argv[i], "-not_selected")) { |
| if (set_printer_status(PRINTER_SELECTED, 1)) { |
| retval = 1; |
| } |
| |
| } else if (!strcmp(argv[i], "-error")) { |
| if (set_printer_status(PRINTER_NOT_ERROR, 1)) { |
| retval = 1; |
| } |
| |
| } else if (!strcmp(argv[i], "-no_error")) { |
| if (set_printer_status(PRINTER_NOT_ERROR, 0)) { |
| retval = 1; |
| } |
| |
| } else if (!strcmp(argv[i], "-read_data")) { |
| if (read_printer_data()) { |
| retval = 1; |
| } |
| |
| } else if (!strcmp(argv[i], "-write_data")) { |
| if (write_printer_data()) { |
| retval = 1; |
| } |
| |
| } else if (!strcmp(argv[i], "-NB_read_data")) { |
| if (read_NB_printer_data()) { |
| retval = 1; |
| } |
| |
| } else { |
| usage(argv[i]); |
| retval = 1; |
| } |
| } |
| |
| exit(retval); |
| } |