1 /*-
2 * Copyright (c) 2017 Baptiste Daroussin <[email protected]>
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 #include <sys/procdesc.h>
29 #include <sys/wait.h>
30
31 #include <err.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 *
start_pr(char * file1,char * file2)45 start_pr(char *file1, char *file2)
46 {
47 int pfd[2];
48 int pr_pd;
49 pid_t pid;
50 char *header;
51 struct pr *pr;
52
53 pr = xcalloc(1, sizeof(*pr));
54
55 xasprintf(&header, "%s %s %s", diffargs, file1, file2);
56 signal(SIGPIPE, SIG_IGN);
57 fflush(stdout);
58 rewind(stdout);
59 if (pipe(pfd) == -1)
60 err(2, "pipe");
61 switch ((pid = pdfork(&pr_pd, PD_CLOEXEC))) {
62 case -1:
63 status |= 2;
64 free(header);
65 err(2, "No more processes");
66 case 0:
67 /* child */
68 if (pfd[0] != STDIN_FILENO) {
69 dup2(pfd[0], STDIN_FILENO);
70 close(pfd[0]);
71 }
72 close(pfd[1]);
73 execl(_PATH_PR, _PATH_PR, "-h", header, (char *)0);
74 _exit(127);
75 default:
76
77 /* parent */
78 if (pfd[1] != STDOUT_FILENO) {
79 pr->ostdout = dup(STDOUT_FILENO);
80 dup2(pfd[1], STDOUT_FILENO);
81 close(pfd[1]);
82 }
83 close(pfd[0]);
84 rewind(stdout);
85 free(header);
86 pr->kq = kqueue();
87 if (pr->kq == -1)
88 err(2, "kqueue");
89 pr->e = xmalloc(sizeof(struct kevent));
90 EV_SET(pr->e, pr_pd, EVFILT_PROCDESC, EV_ADD, NOTE_EXIT, 0,
91 NULL);
92 if (kevent(pr->kq, pr->e, 1, NULL, 0, NULL) == -1)
93 err(2, "kevent");
94 }
95 return (pr);
96 }
97
98 /* close the pipe to pr and restore stdout */
99 void
stop_pr(struct pr * pr)100 stop_pr(struct pr *pr)
101 {
102 int wstatus;
103
104 if (pr == NULL)
105 return;
106
107 fflush(stdout);
108 if (pr->ostdout != STDOUT_FILENO) {
109 close(STDOUT_FILENO);
110 dup2(pr->ostdout, STDOUT_FILENO);
111 close(pr->ostdout);
112 }
113 if (kevent(pr->kq, NULL, 0, pr->e, 1, NULL) == -1)
114 err(2, "kevent");
115 wstatus = pr->e[0].data;
116 close(pr->kq);
117 free(pr);
118 if (WIFEXITED(wstatus) && WEXITSTATUS(wstatus) != 0)
119 errx(2, "pr exited abnormally");
120 else if (WIFSIGNALED(wstatus))
121 errx(2, "pr killed by signal %d",
122 WTERMSIG(wstatus));
123 }
124