1 /*- 2 * Copyright (c) 2010 Jilles Tjoelker 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 */ 26 27 #include <sys/select.h> 28 29 #include <err.h> 30 #include <stdio.h> 31 #include <unistd.h> 32 33 /* 34 * Check that pipes can be selected for writing in the reverse direction. 35 */ 36 int 37 main(void) 38 { 39 int pip[2]; 40 fd_set set; 41 int n; 42 43 if (pipe(pip) == -1) 44 err(1, "FAIL: pipe"); 45 46 FD_ZERO(&set); 47 FD_SET(pip[0], &set); 48 n = select(pip[1] + 1, NULL, &set, NULL, &(struct timeval){ 0, 0 }); 49 if (n != 1) 50 errx(1, "FAIL: select initial reverse direction"); 51 52 n = write(pip[0], "x", 1); 53 if (n != 1) 54 err(1, "FAIL: write reverse direction"); 55 56 FD_ZERO(&set); 57 FD_SET(pip[0], &set); 58 n = select(pip[1] + 1, NULL, &set, NULL, &(struct timeval){ 0, 0 }); 59 if (n != 1) 60 errx(1, "FAIL: select reverse direction after write"); 61 62 printf("PASS\n"); 63 64 return (0); 65 } 66