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/cdefs.h> 28 __FBSDID("$FreeBSD$"); 29 30 #include <sys/procdesc.h> 31 #include <sys/wait.h> 32 33 #include <err.h> 34 #include <paths.h> 35 #include <signal.h> 36 #include <stdio.h> 37 #include <stdlib.h> 38 #include <unistd.h> 39 40 #include "pr.h" 41 #include "diff.h" 42 #include "xmalloc.h" 43 44 #define _PATH_PR "/usr/bin/pr" 45 46 struct pr * 47 start_pr(char *file1, char *file2) 48 { 49 int pfd[2]; 50 int pr_pd; 51 pid_t pid; 52 char *header; 53 struct pr *pr; 54 55 pr = xcalloc(1, sizeof(*pr)); 56 57 xasprintf(&header, "%s %s %s", diffargs, file1, file2); 58 signal(SIGPIPE, SIG_IGN); 59 fflush(stdout); 60 rewind(stdout); 61 if (pipe(pfd) == -1) 62 err(2, "pipe"); 63 switch ((pid = pdfork(&pr_pd, PD_CLOEXEC))) { 64 case -1: 65 status |= 2; 66 free(header); 67 err(2, "No more processes"); 68 case 0: 69 /* child */ 70 if (pfd[0] != STDIN_FILENO) { 71 dup2(pfd[0], STDIN_FILENO); 72 close(pfd[0]); 73 } 74 close(pfd[1]); 75 execl(_PATH_PR, _PATH_PR, "-h", header, (char *)0); 76 _exit(127); 77 default: 78 79 /* parent */ 80 if (pfd[1] != STDOUT_FILENO) { 81 pr->ostdout = dup(STDOUT_FILENO); 82 dup2(pfd[1], STDOUT_FILENO); 83 close(pfd[1]); 84 close(pfd[1]); 85 } 86 close(pfd[0]); 87 rewind(stdout); 88 free(header); 89 pr->kq = kqueue(); 90 if (pr->kq == -1) 91 err(2, "kqueue"); 92 pr->e = xmalloc(sizeof(struct kevent)); 93 EV_SET(pr->e, pr_pd, EVFILT_PROCDESC, EV_ADD, NOTE_EXIT, 0, 94 NULL); 95 if (kevent(pr->kq, pr->e, 1, NULL, 0, NULL) == -1) 96 err(2, "kevent"); 97 } 98 return (pr); 99 } 100 101 /* close the pipe to pr and restore stdout */ 102 void 103 stop_pr(struct pr *pr) 104 { 105 int wstatus; 106 107 if (pr == NULL) 108 return; 109 110 fflush(stdout); 111 if (pr->ostdout != STDOUT_FILENO) { 112 close(STDOUT_FILENO); 113 dup2(pr->ostdout, STDOUT_FILENO); 114 close(pr->ostdout); 115 } 116 if (kevent(pr->kq, NULL, 0, pr->e, 1, NULL) == -1) 117 err(2, "kevent"); 118 wstatus = pr->e[0].data; 119 close(pr->kq); 120 free(pr); 121 if (WIFEXITED(wstatus) && WEXITSTATUS(wstatus) != 0) 122 errx(2, "pr exited abnormally"); 123 else if (WIFSIGNALED(wstatus)) 124 errx(2, "pr killed by signal %d", 125 WTERMSIG(wstatus)); 126 } 127