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: stable/12/usr.bin/diff/pr.c 371729 2022-03-12 18:20:37Z dim $");
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 *
start_pr(char * file1,char * file2)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 }
85 close(pfd[0]);
86 rewind(stdout);
87 free(header);
88 pr->kq = kqueue();
89 if (pr->kq == -1)
90 err(2, "kqueue");
91 pr->e = xmalloc(sizeof(struct kevent));
92 EV_SET(pr->e, pr_pd, EVFILT_PROCDESC, EV_ADD, NOTE_EXIT, 0,
93 NULL);
94 if (kevent(pr->kq, pr->e, 1, NULL, 0, NULL) == -1)
95 err(2, "kevent");
96 }
97 return (pr);
98 }
99
100 /* close the pipe to pr and restore stdout */
101 void
stop_pr(struct pr * pr)102 stop_pr(struct pr *pr)
103 {
104 int wstatus;
105
106 if (pr == NULL)
107 return;
108
109 fflush(stdout);
110 if (pr->ostdout != STDOUT_FILENO) {
111 close(STDOUT_FILENO);
112 dup2(pr->ostdout, STDOUT_FILENO);
113 close(pr->ostdout);
114 }
115 if (kevent(pr->kq, NULL, 0, pr->e, 1, NULL) == -1)
116 err(2, "kevent");
117 wstatus = pr->e[0].data;
118 close(pr->kq);
119 free(pr);
120 if (WIFEXITED(wstatus) && WEXITSTATUS(wstatus) != 0)
121 errx(2, "pr exited abnormally");
122 else if (WIFSIGNALED(wstatus))
123 errx(2, "pr killed by signal %d",
124 WTERMSIG(wstatus));
125 }
126