1/* $NetBSD: main.c,v 1.12 2013/07/03 14:29:28 matt 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("@(#) Copyright (c) 1988 Mark Nudelman."); 36__COPYRIGHT("@(#) Copyright (c) 1988, 1993 " 37"Regents of the University of California. All rights reserved."); 38#endif /* not lint */ 39 40#ifndef lint 41#if 0 42static char sccsid[] = "@(#)main.c 8.1 (Berkeley) 6/7/93"; 43#else 44__RCSID("$NetBSD: main.c,v 1.12 2013/07/03 14:29:28 matt Exp $"); 45#endif 46#endif /* not lint */ 47 48/* 49 * Entry point, initialization, miscellaneous routines. 50 */ 51 52#include <sys/types.h> 53#include <sys/file.h> 54#include <stdio.h> 55#include <string.h> 56#include <errno.h> 57#include <stdlib.h> 58#include <unistd.h> 59 60#include "less.h" 61#include "extern.h" 62 63int ispipe; 64int new_file; 65int is_tty; 66char *current_file, *previous_file, *current_name, *next_name; 67off_t prev_pos; 68int any_display; 69int scroll_lines; 70int ac; 71char **av; 72int curr_ac; 73int quitting; 74 75static void cat_file __P((void)); 76/* 77 * Edit a new file. 78 * Filename "-" means standard input. 79 * No filename means the "current" file, from the command line. 80 */ 81int 82edit(filename) 83 char *filename; 84{ 85 int f; 86 char *m; 87 off_t initial_pos; 88 static int didpipe; 89 char message[100], *p; 90 91 initial_pos = NULL_POSITION; 92 if (filename == NULL || *filename == '\0') { 93 if (curr_ac >= ac) { 94 error("No current file"); 95 return(0); 96 } 97 filename = save(av[curr_ac]); 98 } 99 else if (strcmp(filename, "#") == 0) { 100 if (*previous_file == '\0') { 101 error("no previous file"); 102 return(0); 103 } 104 filename = save(previous_file); 105 initial_pos = prev_pos; 106 } else 107 filename = save(filename); 108 109 /* use standard input. */ 110 if (!strcmp(filename, "-")) { 111 if (didpipe) { 112 error("Can view standard input only once"); 113 return(0); 114 } 115 f = 0; 116 } 117 else if ((m = bad_file(filename, message, sizeof(message))) != NULL) { 118 error(m); 119 free(filename); 120 return(0); 121 } 122 else if ((f = open(filename, O_RDONLY, 0)) < 0) { 123 (void)snprintf(message, sizeof(message), "%s: %s", filename, 124 strerror(errno)); 125 error(message); 126 free(filename); 127 return(0); 128 } 129 130 if (isatty(f)) { 131 /* 132 * Not really necessary to call this an error, 133 * but if the control terminal (for commands) 134 * and the input file (for data) are the same, 135 * we get weird results at best. 136 */ 137 error("Can't take input from a terminal"); 138 if (f > 0) 139 (void)close(f); 140 (void)free(filename); 141 return(0); 142 } 143 144 /* 145 * We are now committed to using the new file. 146 * Close the current input file and set up to use the new one. 147 */ 148 if (file > 0) 149 (void)close(file); 150 new_file = 1; 151 if (previous_file != NULL) 152 free(previous_file); 153 previous_file = current_file; 154 current_file = filename; 155 pos_clear(); 156 prev_pos = position(TOP); 157 ispipe = (f == 0); 158 if (ispipe) { 159 didpipe = 1; 160 current_name = "stdin"; 161 } else 162 current_name = (p = rindex(filename, '/')) ? p + 1 : filename; 163 if (curr_ac >= ac) 164 next_name = NULL; 165 else 166 next_name = av[curr_ac + 1]; 167 file = f; 168 ch_init(cbufs, 0); 169 init_mark(); 170 171 if (is_tty) { 172 int no_display = !any_display; 173 any_display = 1; 174 if (no_display && errmsgs > 0) { 175 /* 176 * We displayed some messages on error output 177 * (file descriptor 2; see error() function). 178 * Before erasing the screen contents, 179 * display the file name and wait for a keystroke. 180 */ 181 error(filename); 182 } 183 /* 184 * Indicate there is nothing displayed yet. 185 */ 186 if (initial_pos != NULL_POSITION) 187 jump_loc(initial_pos); 188 clr_linenum(); 189 } 190 return(1); 191} 192 193/* 194 * Edit the next file in the command line list. 195 */ 196void 197next_file(n) 198 int n; 199{ 200 if (curr_ac + n >= ac) { 201 if (quit_at_eof || position(TOP) == NULL_POSITION) 202 quit(); 203 error("No (N-th) next file"); 204 } 205 else 206 (void)edit(av[curr_ac += n]); 207} 208 209/* 210 * Edit the previous file in the command line list. 211 */ 212void 213prev_file(n) 214 int n; 215{ 216 if (curr_ac - n < 0) 217 error("No (N-th) previous file"); 218 else 219 (void)edit(av[curr_ac -= n]); 220} 221 222/* 223 * copy a file directly to standard output; used if stdout is not a tty. 224 * the only processing is to squeeze multiple blank input lines. 225 */ 226static void 227cat_file() 228{ 229 int c, empty; 230 231 if (squeeze) { 232 empty = 0; 233 while ((c = ch_forw_get()) != EOI) 234 if (c != '\n') { 235 putchr(c); 236 empty = 0; 237 } 238 else if (empty < 2) { 239 putchr(c); 240 ++empty; 241 } 242 } 243 else while ((c = ch_forw_get()) != EOI) 244 putchr(c); 245 flush(); 246} 247 248int 249main(argc, argv) 250 int argc; 251 char **argv; 252{ 253 int envargc, argcnt; 254 char *envargv[3]; 255 256 /* 257 * Process command line arguments and MORE environment arguments. 258 * Command line arguments override environment arguments. 259 */ 260 if ((envargv[1] = getenv("MORE")) != NULL) { 261 envargc = 2; 262 envargv[0] = "more"; 263 envargv[2] = NULL; 264 (void)option(envargc, envargv); 265 } 266 argcnt = option(argc, argv); 267 argv += argcnt; 268 argc -= argcnt; 269 270 /* 271 * Set up list of files to be examined. 272 */ 273 ac = argc; 274 av = argv; 275 curr_ac = 0; 276 277 /* 278 * Set up terminal, etc. 279 */ 280 is_tty = isatty(1); 281 if (!is_tty) { 282 /* 283 * Output is not a tty. 284 * Just copy the input file(s) to output. 285 */ 286 if (ac < 1) { 287 (void)edit("-"); 288 cat_file(); 289 } else { 290 do { 291 (void)edit((char *)NULL); 292 if (file >= 0) 293 cat_file(); 294 } while (++curr_ac < ac); 295 } 296 exit(0); 297 } 298 299 raw_mode(1); 300 get_term(); 301 open_getchr(); 302 init(); 303 init_signals(1); 304 305 /* select the first file to examine. */ 306 if (ac < 1) 307 (void)edit("-"); /* Standard input */ 308 else { 309 /* 310 * Try all the files named as command arguments. 311 * We are simply looking for one which can be 312 * opened without error. 313 */ 314 do { 315 (void)edit((char *)NULL); 316 } while (file < 0 && ++curr_ac < ac); 317 } 318 319 if (file >= 0) 320 commands(); 321 quit(); 322} 323 324/* 325 * Copy a string to a "safe" place 326 * (that is, to a buffer allocated by malloc). 327 */ 328char * 329save(s) 330 char *s; 331{ 332 char *p; 333 334 p = strdup(s); 335 if (p == NULL) 336 { 337 error("cannot allocate memory"); 338 quit(); 339 } 340 return(p); 341} 342 343/* 344 * Exit the program. 345 */ 346void 347quit() 348{ 349 /* 350 * Put cursor at bottom left corner, clear the line, 351 * reset the terminal modes, and exit. 352 */ 353 quitting = 1; 354 lower_left(); 355 clear_eol(); 356 deinit(); 357 flush(); 358 raw_mode(0); 359 exit(0); 360} 361