1 /* $Id: term_tag.c,v 1.6 2021/03/30 17:16:55 schwarze 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 "config.h"
21
22 #include <sys/types.h>
23
24 #include <errno.h>
25 #include <fcntl.h>
26 #include <signal.h>
27 #include <stddef.h>
28 #include <stdio.h>
29 #include <stdlib.h>
30 #include <string.h>
31 #include <unistd.h>
32
33 #include "mandoc.h"
34 #include "roff.h"
35 #include "roff_int.h"
36 #include "tag.h"
37 #include "term_tag.h"
38
39 static void tag_signal(int) __attribute__((__noreturn__));
40
41 static struct tag_files tag_files;
42
43
44 /*
45 * Prepare for using a pager.
46 * Not all pagers are capable of using a tag file,
47 * but for simplicity, create it anyway.
48 */
49 struct tag_files *
term_tag_init(const char * outfilename,const char * suffix,const char * tagfilename)50 term_tag_init(const char *outfilename, const char *suffix,
51 const char *tagfilename)
52 {
53 struct sigaction sa;
54 int ofd; /* In /tmp/, dup(2)ed to stdout. */
55 int tfd;
56
57 ofd = tfd = -1;
58 tag_files.tfs = NULL;
59 tag_files.tcpgid = -1;
60
61 /* Clean up when dying from a signal. */
62
63 memset(&sa, 0, sizeof(sa));
64 sigfillset(&sa.sa_mask);
65 sa.sa_handler = tag_signal;
66 sigaction(SIGHUP, &sa, NULL);
67 sigaction(SIGINT, &sa, NULL);
68 sigaction(SIGTERM, &sa, NULL);
69
70 /*
71 * POSIX requires that a process calling tcsetpgrp(3)
72 * from the background gets a SIGTTOU signal.
73 * In that case, do not stop.
74 */
75
76 sa.sa_handler = SIG_IGN;
77 sigaction(SIGTTOU, &sa, NULL);
78
79 /* Save the original standard output for use by the pager. */
80
81 if ((tag_files.ofd = dup(STDOUT_FILENO)) == -1) {
82 mandoc_msg(MANDOCERR_DUP, 0, 0, "%s", strerror(errno));
83 goto fail;
84 }
85
86 /* Create both temporary output files. */
87
88 if (outfilename == NULL) {
89 (void)snprintf(tag_files.ofn, sizeof(tag_files.ofn),
90 "/tmp/man.XXXXXXXXXX%s", suffix);
91 if ((ofd = mkstemps(tag_files.ofn, strlen(suffix))) == -1) {
92 mandoc_msg(MANDOCERR_MKSTEMP, 0, 0,
93 "%s: %s", tag_files.ofn, strerror(errno));
94 goto fail;
95 }
96 } else {
97 (void)strlcpy(tag_files.ofn, outfilename,
98 sizeof(tag_files.ofn));
99 unlink(outfilename);
100 ofd = open(outfilename, O_WRONLY | O_CREAT | O_EXCL, 0644);
101 if (ofd == -1) {
102 mandoc_msg(MANDOCERR_OPEN, 0, 0,
103 "%s: %s", outfilename, strerror(errno));
104 goto fail;
105 }
106 }
107 if (tagfilename == NULL) {
108 (void)strlcpy(tag_files.tfn, "/tmp/man.XXXXXXXXXX",
109 sizeof(tag_files.tfn));
110 if ((tfd = mkstemp(tag_files.tfn)) == -1) {
111 mandoc_msg(MANDOCERR_MKSTEMP, 0, 0,
112 "%s: %s", tag_files.tfn, strerror(errno));
113 goto fail;
114 }
115 } else {
116 (void)strlcpy(tag_files.tfn, tagfilename,
117 sizeof(tag_files.tfn));
118 unlink(tagfilename);
119 tfd = open(tagfilename, O_WRONLY | O_CREAT | O_EXCL, 0644);
120 if (tfd == -1) {
121 mandoc_msg(MANDOCERR_OPEN, 0, 0,
122 "%s: %s", tagfilename, strerror(errno));
123 goto fail;
124 }
125 }
126 if ((tag_files.tfs = fdopen(tfd, "w")) == NULL) {
127 mandoc_msg(MANDOCERR_FDOPEN, 0, 0, "%s", strerror(errno));
128 goto fail;
129 }
130 tfd = -1;
131 if (dup2(ofd, STDOUT_FILENO) == -1) {
132 mandoc_msg(MANDOCERR_DUP, 0, 0, "%s", strerror(errno));
133 goto fail;
134 }
135 close(ofd);
136 return &tag_files;
137
138 fail:
139 term_tag_unlink();
140 if (ofd != -1)
141 close(ofd);
142 if (tfd != -1)
143 close(tfd);
144 if (tag_files.ofd != -1) {
145 close(tag_files.ofd);
146 tag_files.ofd = -1;
147 }
148 return NULL;
149 }
150
151 void
term_tag_write(struct roff_node * n,size_t line)152 term_tag_write(struct roff_node *n, size_t line)
153 {
154 const char *cp;
155 int len;
156
157 if (tag_files.tfs == NULL)
158 return;
159 cp = n->tag == NULL ? n->child->string : n->tag;
160 if (cp[0] == '\\' && (cp[1] == '&' || cp[1] == 'e'))
161 cp += 2;
162 len = strcspn(cp, " \t\\");
163 fprintf(tag_files.tfs, "%.*s %s %zu\n",
164 len, cp, tag_files.ofn, line);
165 }
166
167 /*
168 * Close both output files and restore the original standard output
169 * to the terminal. In the unlikely case that the latter fails,
170 * trying to start a pager would be useless, so report the failure
171 * to the main program.
172 */
173 int
term_tag_close(void)174 term_tag_close(void)
175 {
176 int irc = 0;
177
178 if (tag_files.tfs != NULL) {
179 fclose(tag_files.tfs);
180 tag_files.tfs = NULL;
181 }
182 if (tag_files.ofd != -1) {
183 fflush(stdout);
184 if ((irc = dup2(tag_files.ofd, STDOUT_FILENO)) == -1)
185 mandoc_msg(MANDOCERR_DUP, 0, 0, "%s", strerror(errno));
186 close(tag_files.ofd);
187 tag_files.ofd = -1;
188 }
189 return irc;
190 }
191
192 void
term_tag_unlink(void)193 term_tag_unlink(void)
194 {
195 pid_t tc_pgid;
196
197 if (tag_files.tcpgid != -1) {
198 tc_pgid = tcgetpgrp(STDOUT_FILENO);
199 if (tc_pgid == tag_files.pager_pid ||
200 tc_pgid == getpgid(0) ||
201 getpgid(tc_pgid) == -1)
202 (void)tcsetpgrp(STDOUT_FILENO, tag_files.tcpgid);
203 }
204 if (strncmp(tag_files.ofn, "/tmp/man.", 9) == 0) {
205 unlink(tag_files.ofn);
206 *tag_files.ofn = '\0';
207 }
208 if (strncmp(tag_files.tfn, "/tmp/man.", 9) == 0) {
209 unlink(tag_files.tfn);
210 *tag_files.tfn = '\0';
211 }
212 }
213
214 static void
tag_signal(int signum)215 tag_signal(int signum)
216 {
217 struct sigaction sa;
218
219 term_tag_unlink();
220 memset(&sa, 0, sizeof(sa));
221 sigemptyset(&sa.sa_mask);
222 sa.sa_handler = SIG_DFL;
223 sigaction(signum, &sa, NULL);
224 kill(getpid(), signum);
225 /* NOTREACHED */
226 _exit(1);
227 }
228