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 * 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 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 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 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 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