1 /* 2 * Copyright (c) 2006 Darren Tucker 3 * 4 * Permission to use, copy, modify, and distribute this software for any 5 * purpose with or without fee is hereby granted, provided that the above 6 * copyright notice and this permission notice appear in all copies. 7 * 8 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 9 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 10 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 11 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 12 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 13 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 14 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 15 */ 16 17 #include <sys/types.h> 18 #include <sys/stat.h> 19 20 #include <fcntl.h> 21 #include <stdio.h> 22 #include <stdlib.h> 23 #include <unistd.h> 24 25 #define NUM_OPENS 10 26 27 void 28 fail(char *msg) 29 { 30 fprintf(stderr, "closefrom: %s\n", msg); 31 exit(1); 32 } 33 34 int 35 main(void) 36 { 37 int i, max, fds[NUM_OPENS]; 38 char buf[512]; 39 40 for (i = 0; i < NUM_OPENS; i++) 41 if ((fds[i] = open("/dev/null", "r")) == -1) 42 exit(0); /* can't test */ 43 max = i - 1; 44 45 /* should close last fd only */ 46 closefrom(fds[max]); 47 if (close(fds[max]) != -1) 48 fail("failed to close highest fd"); 49 50 /* make sure we can still use remaining descriptors */ 51 for (i = 0; i < max; i++) 52 if (read(fds[i], buf, sizeof(buf)) == -1) 53 fail("closed descriptors it should not have"); 54 55 /* should close all fds */ 56 closefrom(fds[0]); 57 for (i = 0; i < NUM_OPENS; i++) 58 if (close(fds[i]) != -1) 59 fail("failed to close from lowest fd"); 60 } 61