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 <paths.h> 32 #include <signal.h> 33 #include <stdio.h> 34 #include <stdlib.h> 35 #include <unistd.h> 36 37 #include "pr.h" 38 #include "diff.h" 39 #include "xmalloc.h" 40 41 #define _PATH_PR "/usr/bin/pr" 42 43 struct pr * 44 start_pr(char *file1, char *file2) 45 { 46 int pfd[2]; 47 int pr_pd; 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 rewind(stdout); 58 if (pipe(pfd) == -1) 59 err(2, "pipe"); 60 switch ((pid = pdfork(&pr_pd, PD_CLOEXEC))) { 61 case -1: 62 status |= 2; 63 free(header); 64 err(2, "No more processes"); 65 case 0: 66 /* child */ 67 if (pfd[0] != STDIN_FILENO) { 68 dup2(pfd[0], STDIN_FILENO); 69 close(pfd[0]); 70 } 71 close(pfd[1]); 72 execl(_PATH_PR, _PATH_PR, "-h", header, (char *)0); 73 _exit(127); 74 default: 75 76 /* parent */ 77 if (pfd[1] != STDOUT_FILENO) { 78 pr->ostdout = dup(STDOUT_FILENO); 79 dup2(pfd[1], STDOUT_FILENO); 80 close(pfd[1]); 81 } 82 close(pfd[0]); 83 rewind(stdout); 84 free(header); 85 pr->kq = kqueue(); 86 if (pr->kq == -1) 87 err(2, "kqueue"); 88 pr->e = xmalloc(sizeof(struct kevent)); 89 EV_SET(pr->e, pr_pd, EVFILT_PROCDESC, EV_ADD, NOTE_EXIT, 0, 90 NULL); 91 if (kevent(pr->kq, pr->e, 1, NULL, 0, NULL) == -1) 92 err(2, "kevent"); 93 } 94 return (pr); 95 } 96 97 /* close the pipe to pr and restore stdout */ 98 void 99 stop_pr(struct pr *pr) 100 { 101 int wstatus; 102 103 if (pr == NULL) 104 return; 105 106 fflush(stdout); 107 if (pr->ostdout != STDOUT_FILENO) { 108 close(STDOUT_FILENO); 109 dup2(pr->ostdout, STDOUT_FILENO); 110 close(pr->ostdout); 111 } 112 if (kevent(pr->kq, NULL, 0, pr->e, 1, NULL) == -1) 113 err(2, "kevent"); 114 wstatus = pr->e[0].data; 115 close(pr->kq); 116 free(pr); 117 if (WIFEXITED(wstatus) && WEXITSTATUS(wstatus) != 0) 118 errx(2, "pr exited abnormally"); 119 else if (WIFSIGNALED(wstatus)) 120 errx(2, "pr killed by signal %d", 121 WTERMSIG(wstatus)); 122 } 123