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 *
start_pr(char * file1,char * file2)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
stop_pr(struct pr * pr)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