/* * Copyright (c) 2008, Kohsuke Ohtani * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the author nor the names of any co-contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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. */ /* * fifo.c - test FIFO function */ #include #include #include #include #include #include #include #include int main(int argc, char *argv[]) { int pid, fd1, fd2, len; char buf1[256], buf2[256]; printf("FIFO test program\n"); if (mknod("/fifo/test", S_IFIFO | 0666, 0) == -1) { perror("mkfifo"); exit(1); } pid = vfork(); if (pid == -1) { perror("fork"); exit(1); } if (pid == 0) { /* child */ printf("child: task=%x\n", (int)task_self()); fd1 = open("/fifo/test", O_RDONLY); if (fd1 == -1) { perror("open"); exit(1); } for (;;) { printf("child: reading data from FIFO\n"); len = read(fd1, buf1, sizeof(buf1) - 1); if (len == 0) break; buf1[len] = '\0'; printf("child: length=%d data=%s\n", len, buf1); } close(fd1); printf("child: exit\n"); exit(0); } printf("parent: task=%x\n", (int)task_self()); fd2 = open("/fifo/test", O_WRONLY); if (fd2 == -1) { perror("open"); exit(1); } for (;;) { printf("parent: please input string...\n"); fgets(buf2, sizeof(buf2) - 1, stdin); if (feof(stdin)) break; printf("parent: writing to FIFO\n"); write(fd2, buf2, strlen(buf2)); } close(fd2); printf("parent: exit\n"); exit(0); return 0; }