1 /* $OpenBSD: term_tag.c,v 1.6 2021/02/19 19:49:49 kn Exp $ */
2 /*
3 * Copyright (c) 2015,2016,2018,2019,2020 Ingo Schwarze <schwarze@openbsd.org>
4 *
5 * Permission to use, copy, modify, and distribute this software for any
6 * purpose with or without fee is hereby granted, provided that the above
7 * copyright notice and this permission notice appear in all copies.
8 *
9 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16 *
17 * Functions to write a ctags(1) file.
18 * For use by the mandoc(1) ASCII and UTF-8 formatters only.
19 */
20 #include <sys/types.h>
21
22 #include <errno.h>
23 #include <fcntl.h>
24 #include <signal.h>
25 #include <stddef.h>
26 #include <stdio.h>
27 #include <stdlib.h>
28 #include <string.h>
29 #include <unistd.h>
30
31 #include "mandoc.h"
32 #include "roff.h"
33 #include "roff_int.h"
34 #include "tag.h"
35 #include "term_tag.h"
36
37 static void tag_signal(int) __attribute__((__noreturn__));
38
39 static struct tag_files tag_files;
40
41
42 /*
43 * Prepare for using a pager.
44 * Not all pagers are capable of using a tag file,
45 * but for simplicity, create it anyway.
46 */
47 struct tag_files *
term_tag_init(const char * outfilename,const char * suffix,const char * tagfilename)48 term_tag_init(const char *outfilename, const char *suffix,
49 const char *tagfilename)
50 {
51 struct sigaction sa;
52 int ofd; /* In /tmp/, dup(2)ed to stdout. */
53 int tfd;
54
55 ofd = tfd = -1;
56 tag_files.tfs = NULL;
57 tag_files.tcpgid = -1;
58
59 /* Clean up when dying from a signal. */
60
61 memset(&sa, 0, sizeof(sa));
62 sigfillset(&sa.sa_mask);
63 sa.sa_handler = tag_signal;
64 sigaction(SIGHUP, &sa, NULL);
65 sigaction(SIGINT, &sa, NULL);
66 sigaction(SIGTERM, &sa, NULL);
67
68 /*
69 * POSIX requires that a process calling tcsetpgrp(3)
70 * from the background gets a SIGTTOU signal.
71 * In that case, do not stop.
72 */
73
74 sa.sa_handler = SIG_IGN;
75 sigaction(SIGTTOU, &sa, NULL);
76
77 /* Save the original standard output for use by the pager. */
78
79 if ((tag_files.ofd = dup(STDOUT_FILENO)) == -1) {
80 mandoc_msg(MANDOCERR_DUP, 0, 0, "%s", strerror(errno));
81 goto fail;
82 }
83
84 /* Create both temporary output files. */
85
86 if (outfilename == NULL) {
87 (void)snprintf(tag_files.ofn, sizeof(tag_files.ofn),
88 "/tmp/man.XXXXXXXXXX%s", suffix);
89 if ((ofd = mkstemps(tag_files.ofn, strlen(suffix))) == -1) {
90 mandoc_msg(MANDOCERR_MKSTEMP, 0, 0,
91 "%s: %s", tag_files.ofn, strerror(errno));
92 goto fail;
93 }
94 } else {
95 (void)strlcpy(tag_files.ofn, outfilename,
96 sizeof(tag_files.ofn));
97 unlink(outfilename);
98 ofd = open(outfilename, O_WRONLY | O_CREAT | O_EXCL, 0644);
99 if (ofd == -1) {
100 mandoc_msg(MANDOCERR_OPEN, 0, 0,
101 "%s: %s", outfilename, strerror(errno));
102 goto fail;
103 }
104 }
105 if (tagfilename == NULL) {
106 (void)strlcpy(tag_files.tfn, "/tmp/man.XXXXXXXXXX",
107 sizeof(tag_files.tfn));
108 if ((tfd = mkstemp(tag_files.tfn)) == -1) {
109 mandoc_msg(MANDOCERR_MKSTEMP, 0, 0,
110 "%s: %s", tag_files.tfn, strerror(errno));
111 goto fail;
112 }
113 } else {
114 (void)strlcpy(tag_files.tfn, tagfilename,
115 sizeof(tag_files.tfn));
116 unlink(tagfilename);
117 tfd = open(tagfilename, O_WRONLY | O_CREAT | O_EXCL, 0644);
118 if (tfd == -1) {
119 mandoc_msg(MANDOCERR_OPEN, 0, 0,
120 "%s: %s", tagfilename, strerror(errno));
121 goto fail;
122 }
123 }
124 if ((tag_files.tfs = fdopen(tfd, "w")) == NULL) {
125 mandoc_msg(MANDOCERR_FDOPEN, 0, 0, "%s", strerror(errno));
126 goto fail;
127 }
128 tfd = -1;
129 if (dup2(ofd, STDOUT_FILENO) == -1) {
130 mandoc_msg(MANDOCERR_DUP, 0, 0, "%s", strerror(errno));
131 goto fail;
132 }
133 close(ofd);
134 return &tag_files;
135
136 fail:
137 term_tag_unlink();
138 if (ofd != -1)
139 close(ofd);
140 if (tfd != -1)
141 close(tfd);
142 if (tag_files.ofd != -1) {
143 close(tag_files.ofd);
144 tag_files.ofd = -1;
145 }
146 return NULL;
147 }
148
149 void
term_tag_write(struct roff_node * n,size_t line)150 term_tag_write(struct roff_node *n, size_t line)
151 {
152 const char *cp;
153 int len;
154
155 if (tag_files.tfs == NULL)
156 return;
157 cp = n->tag == NULL ? n->child->string : n->tag;
158 if (cp[0] == '\\' && (cp[1] == '&' || cp[1] == 'e'))
159 cp += 2;
160 len = strcspn(cp, " \t\\");
161 fprintf(tag_files.tfs, "%.*s %s %zu\n",
162 len, cp, tag_files.ofn, line);
163 }
164
165 /*
166 * Close both output files and restore the original standard output
167 * to the terminal. In the unlikely case that the latter fails,
168 * trying to start a pager would be useless, so report the failure
169 * to the main program.
170 */
171 int
term_tag_close(void)172 term_tag_close(void)
173 {
174 int irc = 0;
175
176 if (tag_files.tfs != NULL) {
177 fclose(tag_files.tfs);
178 tag_files.tfs = NULL;
179 }
180 if (tag_files.ofd != -1) {
181 fflush(stdout);
182 if ((irc = dup2(tag_files.ofd, STDOUT_FILENO)) == -1)
183 mandoc_msg(MANDOCERR_DUP, 0, 0, "%s", strerror(errno));
184 close(tag_files.ofd);
185 tag_files.ofd = -1;
186 }
187 return irc;
188 }
189
190 void
term_tag_unlink(void)191 term_tag_unlink(void)
192 {
193 pid_t tc_pgid;
194
195 if (tag_files.tcpgid != -1) {
196 tc_pgid = tcgetpgrp(STDOUT_FILENO);
197 if (tc_pgid == tag_files.pager_pid ||
198 tc_pgid == getpgid(0) ||
199 getpgid(tc_pgid) == -1)
200 (void)tcsetpgrp(STDOUT_FILENO, tag_files.tcpgid);
201 }
202 if (strncmp(tag_files.ofn, "/tmp/man.", 9) == 0) {
203 unlink(tag_files.ofn);
204 *tag_files.ofn = '\0';
205 }
206 if (strncmp(tag_files.tfn, "/tmp/man.", 9) == 0) {
207 unlink(tag_files.tfn);
208 *tag_files.tfn = '\0';
209 }
210 }
211
212 static void
tag_signal(int signum)213 tag_signal(int signum)
214 {
215 struct sigaction sa;
216
217 term_tag_unlink();
218 memset(&sa, 0, sizeof(sa));
219 sigemptyset(&sa.sa_mask);
220 sa.sa_handler = SIG_DFL;
221 sigaction(signum, &sa, NULL);
222 kill(getpid(), signum);
223 /* NOTREACHED */
224 _exit(1);
225 }
226