1 /* $NetBSD: main.c,v 1.10 2009/01/24 13:43:21 tsutsui Exp $ */ 2 3 /* 4 * Copyright (c) 1988 Mark Nudelman 5 * Copyright (c) 1988, 1993 6 * Regents of the University of California. All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 */ 32 33 #include <sys/cdefs.h> 34 #ifndef lint 35 __COPYRIGHT(\ 36 "@(#) Copyright (c) 1988 Mark Nudelman.\ 37 @(#) Copyright (c) 1988, 1993\ 38 Regents of the University of California. All rights reserved."); 39 #endif /* not lint */ 40 41 #ifndef lint 42 #if 0 43 static char sccsid[] = "@(#)main.c 8.1 (Berkeley) 6/7/93"; 44 #else 45 __RCSID("$NetBSD: main.c,v 1.10 2009/01/24 13:43:21 tsutsui Exp $"); 46 #endif 47 #endif /* not lint */ 48 49 /* 50 * Entry point, initialization, miscellaneous routines. 51 */ 52 53 #include <sys/types.h> 54 #include <sys/file.h> 55 #include <stdio.h> 56 #include <string.h> 57 #include <errno.h> 58 #include <stdlib.h> 59 #include <unistd.h> 60 61 #include "less.h" 62 #include "extern.h" 63 64 int ispipe; 65 int new_file; 66 int is_tty; 67 char *current_file, *previous_file, *current_name, *next_name; 68 off_t prev_pos; 69 int any_display; 70 int scroll_lines; 71 int ac; 72 char **av; 73 int curr_ac; 74 int quitting; 75 76 static void cat_file __P((void)); 77 /* 78 * Edit a new file. 79 * Filename "-" means standard input. 80 * No filename means the "current" file, from the command line. 81 */ 82 int 83 edit(filename) 84 char *filename; 85 { 86 int f; 87 char *m; 88 off_t initial_pos; 89 static int didpipe; 90 char message[100], *p; 91 92 initial_pos = NULL_POSITION; 93 if (filename == NULL || *filename == '\0') { 94 if (curr_ac >= ac) { 95 error("No current file"); 96 return(0); 97 } 98 filename = save(av[curr_ac]); 99 } 100 else if (strcmp(filename, "#") == 0) { 101 if (*previous_file == '\0') { 102 error("no previous file"); 103 return(0); 104 } 105 filename = save(previous_file); 106 initial_pos = prev_pos; 107 } else 108 filename = save(filename); 109 110 /* use standard input. */ 111 if (!strcmp(filename, "-")) { 112 if (didpipe) { 113 error("Can view standard input only once"); 114 return(0); 115 } 116 f = 0; 117 } 118 else if ((m = bad_file(filename, message, sizeof(message))) != NULL) { 119 error(m); 120 free(filename); 121 return(0); 122 } 123 else if ((f = open(filename, O_RDONLY, 0)) < 0) { 124 (void)snprintf(message, sizeof(message), "%s: %s", filename, 125 strerror(errno)); 126 error(message); 127 free(filename); 128 return(0); 129 } 130 131 if (isatty(f)) { 132 /* 133 * Not really necessary to call this an error, 134 * but if the control terminal (for commands) 135 * and the input file (for data) are the same, 136 * we get weird results at best. 137 */ 138 error("Can't take input from a terminal"); 139 if (f > 0) 140 (void)close(f); 141 (void)free(filename); 142 return(0); 143 } 144 145 /* 146 * We are now committed to using the new file. 147 * Close the current input file and set up to use the new one. 148 */ 149 if (file > 0) 150 (void)close(file); 151 new_file = 1; 152 if (previous_file != NULL) 153 free(previous_file); 154 previous_file = current_file; 155 current_file = filename; 156 pos_clear(); 157 prev_pos = position(TOP); 158 ispipe = (f == 0); 159 if (ispipe) { 160 didpipe = 1; 161 current_name = "stdin"; 162 } else 163 current_name = (p = rindex(filename, '/')) ? p + 1 : filename; 164 if (curr_ac >= ac) 165 next_name = NULL; 166 else 167 next_name = av[curr_ac + 1]; 168 file = f; 169 ch_init(cbufs, 0); 170 init_mark(); 171 172 if (is_tty) { 173 int no_display = !any_display; 174 any_display = 1; 175 if (no_display && errmsgs > 0) { 176 /* 177 * We displayed some messages on error output 178 * (file descriptor 2; see error() function). 179 * Before erasing the screen contents, 180 * display the file name and wait for a keystroke. 181 */ 182 error(filename); 183 } 184 /* 185 * Indicate there is nothing displayed yet. 186 */ 187 if (initial_pos != NULL_POSITION) 188 jump_loc(initial_pos); 189 clr_linenum(); 190 } 191 return(1); 192 } 193 194 /* 195 * Edit the next file in the command line list. 196 */ 197 void 198 next_file(n) 199 int n; 200 { 201 if (curr_ac + n >= ac) { 202 if (quit_at_eof || position(TOP) == NULL_POSITION) 203 quit(); 204 error("No (N-th) next file"); 205 } 206 else 207 (void)edit(av[curr_ac += n]); 208 } 209 210 /* 211 * Edit the previous file in the command line list. 212 */ 213 void 214 prev_file(n) 215 int n; 216 { 217 if (curr_ac - n < 0) 218 error("No (N-th) previous file"); 219 else 220 (void)edit(av[curr_ac -= n]); 221 } 222 223 /* 224 * copy a file directly to standard output; used if stdout is not a tty. 225 * the only processing is to squeeze multiple blank input lines. 226 */ 227 static void 228 cat_file() 229 { 230 int c, empty; 231 232 if (squeeze) { 233 empty = 0; 234 while ((c = ch_forw_get()) != EOI) 235 if (c != '\n') { 236 putchr(c); 237 empty = 0; 238 } 239 else if (empty < 2) { 240 putchr(c); 241 ++empty; 242 } 243 } 244 else while ((c = ch_forw_get()) != EOI) 245 putchr(c); 246 flush(); 247 } 248 249 int 250 main(argc, argv) 251 int argc; 252 char **argv; 253 { 254 int envargc, argcnt; 255 char *envargv[2]; 256 257 /* 258 * Process command line arguments and MORE environment arguments. 259 * Command line arguments override environment arguments. 260 */ 261 if ((envargv[1] = getenv("MORE")) != NULL) { 262 envargc = 2; 263 envargv[0] = "more"; 264 envargv[2] = NULL; 265 (void)option(envargc, envargv); 266 } 267 argcnt = option(argc, argv); 268 argv += argcnt; 269 argc -= argcnt; 270 271 /* 272 * Set up list of files to be examined. 273 */ 274 ac = argc; 275 av = argv; 276 curr_ac = 0; 277 278 /* 279 * Set up terminal, etc. 280 */ 281 is_tty = isatty(1); 282 if (!is_tty) { 283 /* 284 * Output is not a tty. 285 * Just copy the input file(s) to output. 286 */ 287 if (ac < 1) { 288 (void)edit("-"); 289 cat_file(); 290 } else { 291 do { 292 (void)edit((char *)NULL); 293 if (file >= 0) 294 cat_file(); 295 } while (++curr_ac < ac); 296 } 297 exit(0); 298 } 299 300 raw_mode(1); 301 get_term(); 302 open_getchr(); 303 init(); 304 init_signals(1); 305 306 /* select the first file to examine. */ 307 if (ac < 1) 308 (void)edit("-"); /* Standard input */ 309 else { 310 /* 311 * Try all the files named as command arguments. 312 * We are simply looking for one which can be 313 * opened without error. 314 */ 315 do { 316 (void)edit((char *)NULL); 317 } while (file < 0 && ++curr_ac < ac); 318 } 319 320 if (file >= 0) 321 commands(); 322 quit(); 323 } 324 325 /* 326 * Copy a string to a "safe" place 327 * (that is, to a buffer allocated by malloc). 328 */ 329 char * 330 save(s) 331 char *s; 332 { 333 char *p; 334 335 p = strdup(s); 336 if (p == NULL) 337 { 338 error("cannot allocate memory"); 339 quit(); 340 } 341 return(p); 342 } 343 344 /* 345 * Exit the program. 346 */ 347 void 348 quit() 349 { 350 /* 351 * Put cursor at bottom left corner, clear the line, 352 * reset the terminal modes, and exit. 353 */ 354 quitting = 1; 355 lower_left(); 356 clear_eol(); 357 deinit(); 358 flush(); 359 raw_mode(0); 360 exit(0); 361 } 362