distrib/utils/more/main.c

   1 /*      $NetBSD: main.c,v 1.9 2004/09/01 01:46:56 chs 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 1.9 2004/09/01 01:46:56 chs 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 }