1 /*- 2 * Copyright (c) 2017 Baptiste Daroussin <bapt@FreeBSD.org> 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 * in this position and unchanged. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR 16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 18 * IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT, 19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 25 */ 26 27 #include <sys/procdesc.h> 28 #include <sys/wait.h> 29 30 #include <err.h> 31 #include <errno.h> 32 #include <paths.h> 33 #include <signal.h> 34 #include <stdio.h> 35 #include <stdlib.h> 36 #include <unistd.h> 37 38 #include "pr.h" 39 #include "diff.h" 40 #include "xmalloc.h" 41 42 #define _PATH_PR "/usr/bin/pr" 43 44 struct pr * 45 start_pr(char *file1, char *file2) 46 { 47 int pfd[2]; 48 pid_t pid; 49 char *header; 50 struct pr *pr; 51 52 pr = xcalloc(1, sizeof(*pr)); 53 54 xasprintf(&header, "%s %s %s", diffargs, file1, file2); 55 signal(SIGPIPE, SIG_IGN); 56 fflush(stdout); 57 if (pipe(pfd) == -1) 58 err(2, "pipe"); 59 switch ((pid = pdfork(&pr->procd, PD_CLOEXEC))) { 60 case -1: 61 err(2, "No more processes"); 62 case 0: 63 /* child */ 64 if (pfd[0] != STDIN_FILENO) { 65 dup2(pfd[0], STDIN_FILENO); 66 close(pfd[0]); 67 } 68 close(pfd[1]); 69 execl(_PATH_PR, _PATH_PR, "-h", header, (char *)0); 70 _exit(127); 71 default: 72 /* parent */ 73 if (pfd[1] == STDOUT_FILENO) { 74 pr->ostdout = STDOUT_FILENO; 75 } else { 76 if ((pr->ostdout = dup(STDOUT_FILENO)) < 0 || 77 dup2(pfd[1], STDOUT_FILENO) < 0) { 78 err(2, "stdout"); 79 } 80 close(pfd[1]); 81 } 82 close(pfd[0]); 83 free(header); 84 } 85 return (pr); 86 } 87 88 /* close the pipe to pr and restore stdout */ 89 void 90 stop_pr(struct pr *pr) 91 { 92 int wstatus; 93 94 if (pr == NULL) 95 return; 96 97 fflush(stdout); 98 if (pr->ostdout != STDOUT_FILENO) { 99 dup2(pr->ostdout, STDOUT_FILENO); 100 close(pr->ostdout); 101 } 102 while (pdwait(pr->procd, &wstatus, WEXITED, NULL, NULL) == -1) { 103 if (errno != EINTR) 104 err(2, "pdwait"); 105 } 106 close(pr->procd); 107 free(pr); 108 if (WIFEXITED(wstatus) && WEXITSTATUS(wstatus) != 0) 109 errx(2, "pr exited abnormally"); 110 else if (WIFSIGNALED(wstatus)) 111 errx(2, "pr killed by signal %d", 112 WTERMSIG(wstatus)); 113 } 114