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- /*
- *
- * Copyright (c) 2003 The Regents of the University of California. All
- * rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- *
- * - Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *
- * - Neither the name of the University nor the names of its
- * contributors may be used to endorse or promote products derived
- * from this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS''
- * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
- * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
- * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR
- * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
- * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
- * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
- * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
- * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- *
- */
-
- /*
- * FUSD - The Framework for UserSpace Devices - Example program
- *
- * Jeremy Elson <jelson@circlemud.org>
- *
- * drums3.c: This example shows how to wait for both FUSD and non-FUSD
- * events at the same time. Instead of using fusd_run, we keep
- * control of main() by using our own select loop.
- *
- * Like the original drums.c, this example creates a bunch of devices
- * in the /dev/drums directory: /dev/drums/bam, /dev/drums/bum, etc.
- * However, it also prints a prompt to the console, asking the user if
- * how loud the drums should be.
- *
- * $Id: drums3.c 12351 2007-01-19 07:22:54Z xiphmont $
- */
- #include <stdio.h>
- #include <stdlib.h>
- #include <string.h>
- #include <ctype.h>
- #include <errno.h>
- #include <unistd.h>
- #include "fusd.h"
- #define MIN(x, y) ((x) < (y) ? (x) : (y))
- static char *drums_strings[] = {"bam", "bum", "beat", "boom",
- "bang", "crash", NULL};
- int volume = 2; /* default volume is 2 */
- ssize_t drums_read(struct fusd_file_info *file, char *user_buffer,
- size_t user_length, loff_t *offset)
- {
- int len;
- char sound[128], *c;
- /* 1st read returns the sound; 2nd returns EOF */
- if (*offset != 0)
- return 0;
- if (volume == 1)
- strcpy(sound, "(you hear nothing)");
- else {
- strcpy(sound, (char *) file->device_info);
- if (volume >= 3)
- for (c = sound; *c; c++)
- *c = toupper(*c);
- if (volume >= 4)
- strcat(sound, "!!!!!");
- }
- strcat(sound, "\n");
- /* NEVER return more data than the user asked for */
- len = MIN(user_length, strlen(sound));
- memcpy(user_buffer, sound, len);
- *offset += len;
- return len;
- }
- int do_open_or_close(struct fusd_file_info *file)
- {
- return 0; /* opens and closes always succeed */
- }
- struct fusd_file_operations drums_fops = {
- open: do_open_or_close,
- read: drums_read,
- close: do_open_or_close
- };
- void read_volume(int fd)
- {
- char buf[100];
- int new_vol = 0, retval;
- if (fd < 0)
- goto prompt;
- retval = read(fd, buf, sizeof(buf)-1);
- if (retval >= 0) {
- buf[retval] = '\0';
- if (*buf == 'q') {
- printf("Goodbye...\n");
- exit(0);
- }
- new_vol = atoi(buf);
- }
- if (new_vol >= 1 && new_vol <= 4) {
- volume = new_vol;
- printf("Volume changed to %d\n", volume);
- } else {
- printf("Invalid volume!\n");
- }
- prompt:
- printf("\nHow loud would you like the /dev/drums?\n");
- printf(" 1 - Inaudible\n");
- printf(" 2 - Quiet\n");
- printf(" 3 - Loud\n");
- printf(" 4 - Permanent ear damage!\n");
- printf(" q - Exit program\n");
- printf("Your choice? ");
- fflush(stdout);
- }
-
- int main(int argc, char *argv[])
- {
- int i;
- char buf[128];
- char devname[128];
- fd_set fds, tmp;
- int max;
- for (i = 0; drums_strings[i] != NULL; i++) {
- sprintf(buf, "/dev/drums/%s", drums_strings[i]);
- sprintf(devname, "drum%s", drums_strings[i]);
- if (fusd_register(buf, "drums", devname, 0666, drums_strings[i], &drums_fops) < 0)
- fprintf(stderr, "%s register failed: %m\n", drums_strings[i]);
- }
- /* print the initial prompt to the user */
- read_volume(-1);
- /* EXAMPLE START drums3.c */
- /* initialize the set */
- FD_ZERO(&fds);
- /* add stdin to the set */
- FD_SET(STDIN_FILENO, &fds);
- max = STDIN_FILENO;
- /* add all FUSD fds to the set */
- fusd_fdset_add(&fds, &max);
- while (1) {
- tmp = fds;
- if (select(max+1, &tmp, NULL, NULL, NULL) < 0)
- perror("selecting");
- else {
- /* if stdin is readable, read the user's response */
- if (FD_ISSET(STDIN_FILENO, &tmp))
- read_volume(STDIN_FILENO);
- /* call any FUSD callbacks that have messages waiting */
- fusd_dispatch_fdset(&tmp);
- }
- }
- /* EXAMPLE STOP drums3.c */
- }
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