contrib/less/main.c

   1 /*
   2  * Copyright (C) 1984-2023  Mark Nudelman
   3  *
   4  * You may distribute under the terms of either the GNU General Public
   5  * License or the Less License, as specified in the README file.
   6  *
   7  * For more information, see the README file.
   8  */
   9
  10
  11 /*
  12  * Entry point, initialization, miscellaneous routines.
  13  */
  14
  15 #include "less.h"
  16 #if MSDOS_COMPILER==WIN32C
  17 #define WIN32_LEAN_AND_MEAN
  18 #include <windows.h>
  19 #endif
  20
  21 public char *   every_first_cmd = NULL;
  22 public int      new_file;
  23 public int      is_tty;
  24 public IFILE    curr_ifile = NULL_IFILE;
  25 public IFILE    old_ifile = NULL_IFILE;
  26 public struct scrpos initial_scrpos;
  27 public POSITION start_attnpos = NULL_POSITION;
  28 public POSITION end_attnpos = NULL_POSITION;
  29 public int      wscroll;
  30 public char *   progname;
  31 public int      quitting;
  32 public int      secure;
  33 public int      dohelp;
  34
  35 #if LOGFILE
  36 public int      logfile = -1;
  37 public int      force_logfile = FALSE;
  38 public char *   namelogfile = NULL;
  39 #endif
  40
  41 #if EDITOR
  42 public char *   editor;
  43 public char *   editproto;
  44 #endif
  45
  46 #if TAGS
  47 extern char *   tags;
  48 extern char *   tagoption;
  49 extern int      jump_sline;
  50 #endif
  51
  52 #ifdef WIN32
  53 static char consoleTitle[256];
  54 #endif
  55
  56 public int      one_screen;
  57 extern int      less_is_more;
  58 extern int      missing_cap;
  59 extern int      know_dumb;
  60 extern int      pr_type;
  61 extern int      quit_if_one_screen;
  62 extern int      no_init;
  63 extern int      errmsgs;
  64 extern int      redraw_on_quit;
  65 extern int      term_init_done;
  66 extern int      first_time;
  67
  68 /*
  69  * Entry point.
  70  */
  71 int main(int argc, char *argv[])
  72 {
  73         IFILE ifile;
  74         char *s;
  75
  76 #ifdef __EMX__
  77         _response(&argc, &argv);
  78         _wildcard(&argc, &argv);
  79 #endif
  80
  81         progname = *argv++;
  82         argc--;
  83
  84 #if SECURE
  85         secure = 1;
  86 #else
  87         secure = 0;
  88         s = lgetenv("LESSSECURE");
  89         if (!isnullenv(s))
  90                 secure = 1;
  91 #endif
  92
  93 #ifdef WIN32
  94         if (getenv("HOME") == NULL)
  95         {
  96                 /*
  97                  * If there is no HOME environment variable,
  98                  * try the concatenation of HOMEDRIVE + HOMEPATH.
  99                  */
 100                 char *drive = getenv("HOMEDRIVE");
 101                 char *path  = getenv("HOMEPATH");
 102                 if (drive != NULL && path != NULL)
 103                 {
 104                         char *env = (char *) ecalloc(strlen(drive) +
 105                                         strlen(path) + 6, sizeof(char));
 106                         strcpy(env, "HOME=");
 107                         strcat(env, drive);
 108                         strcat(env, path);
 109                         putenv(env);
 110                 }
 111         }
 112         GetConsoleTitle(consoleTitle, sizeof(consoleTitle)/sizeof(char));
 113 #endif /* WIN32 */
 114
 115         /*
 116          * Process command line arguments and LESS environment arguments.
 117          * Command line arguments override environment arguments.
 118          */
 119         is_tty = isatty(1);
 120         init_mark();
 121         init_cmds();
 122         init_poll();
 123         get_term();
 124         init_charset();
 125         init_line();
 126         init_cmdhist();
 127         init_option();
 128         init_search();
 129
 130         /*
 131          * If the name of the executable program is "more",
 132          * act like LESS_IS_MORE is set.
 133          */
 134         s = last_component(progname);
 135         if (strcmp(s, "more") == 0)
 136                 less_is_more = 1;
 137
 138         init_prompt();
 139
 140         s = lgetenv(less_is_more ? "MORE" : "LESS");
 141         if (s != NULL)
 142                 scan_option(s);
 143
 144 #define isoptstring(s)  (((s)[0] == '-' || (s)[0] == '+') && (s)[1] != '\0')
 145         while (argc > 0 && (isoptstring(*argv) || isoptpending()))
 146         {
 147                 s = *argv++;
 148                 argc--;
 149                 if (strcmp(s, "--") == 0)
 150                         break;
 151                 scan_option(s);
 152         }
 153 #undef isoptstring
 154
 155         if (isoptpending())
 156         {
 157                 /*
 158                  * Last command line option was a flag requiring a
 159                  * following string, but there was no following string.
 160                  */
 161                 nopendopt();
 162                 quit(QUIT_OK);
 163         }
 164
 165         expand_cmd_tables();
 166
 167 #if EDITOR
 168         editor = lgetenv("VISUAL");
 169         if (editor == NULL || *editor == '\0')
 170         {
 171                 editor = lgetenv("EDITOR");
 172                 if (isnullenv(editor))
 173                         editor = EDIT_PGM;
 174         }
 175         editproto = lgetenv("LESSEDIT");
 176         if (isnullenv(editproto))
 177                 editproto = "%E ?lm+%lm. %g";
 178 #endif
 179
 180         /*
 181          * Call get_ifile with all the command line filenames
 182          * to "register" them with the ifile system.
 183          */
 184         ifile = NULL_IFILE;
 185         if (dohelp)
 186                 ifile = get_ifile(FAKE_HELPFILE, ifile);
 187         while (argc-- > 0)
 188         {
 189 #if (MSDOS_COMPILER && MSDOS_COMPILER != DJGPPC)
 190                 /*
 191                  * Because the "shell" doesn't expand filename patterns,
 192                  * treat each argument as a filename pattern rather than
 193                  * a single filename.
 194                  * Expand the pattern and iterate over the expanded list.
 195                  */
 196                 struct textlist tlist;
 197                 char *filename;
 198                 char *gfilename;
 199                 char *qfilename;
 200
 201                 gfilename = lglob(*argv++);
 202                 init_textlist(&tlist, gfilename);
 203                 filename = NULL;
 204                 while ((filename = forw_textlist(&tlist, filename)) != NULL)
 205                 {
 206                         qfilename = shell_unquote(filename);
 207                         (void) get_ifile(qfilename, ifile);
 208                         free(qfilename);
 209                         ifile = prev_ifile(NULL_IFILE);
 210                 }
 211                 free(gfilename);
 212 #else
 213                 (void) get_ifile(*argv++, ifile);
 214                 ifile = prev_ifile(NULL_IFILE);
 215 #endif
 216         }
 217         /*
 218          * Set up terminal, etc.
 219          */
 220         if (!is_tty)
 221         {
 222                 /*
 223                  * Output is not a tty.
 224                  * Just copy the input file(s) to output.
 225                  */
 226                 set_output(1); /* write to stdout */
 227                 SET_BINARY(1);
 228                 if (edit_first() == 0)
 229                 {
 230                         do {
 231                                 cat_file();
 232                         } while (edit_next(1) == 0);
 233                 }
 234                 quit(QUIT_OK);
 235         }
 236
 237         if (missing_cap && !know_dumb)
 238                 error("WARNING: terminal is not fully functional", NULL_PARG);
 239         open_getchr();
 240         raw_mode(1);
 241         init_signals(1);
 242
 243         /*
 244          * Select the first file to examine.
 245          */
 246 #if TAGS
 247         if (tagoption != NULL || strcmp(tags, "-") == 0)
 248         {
 249                 /*
 250                  * A -t option was given.
 251                  * Verify that no filenames were also given.
 252                  * Edit the file selected by the "tags" search,
 253                  * and search for the proper line in the file.
 254                  */
 255                 if (nifile() > 0)
 256                 {
 257                         error("No filenames allowed with -t option", NULL_PARG);
 258                         quit(QUIT_ERROR);
 259                 }
 260                 findtag(tagoption);
 261                 if (edit_tagfile())  /* Edit file which contains the tag */
 262                         quit(QUIT_ERROR);
 263                 /*
 264                  * Search for the line which contains the tag.
 265                  * Set up initial_scrpos so we display that line.
 266                  */
 267                 initial_scrpos.pos = tagsearch();
 268                 if (initial_scrpos.pos == NULL_POSITION)
 269                         quit(QUIT_ERROR);
 270                 initial_scrpos.ln = jump_sline;
 271         } else
 272 #endif
 273         {
 274                 if (edit_first())
 275                         quit(QUIT_ERROR);
 276                 /*
 277                  * See if file fits on one screen to decide whether
 278                  * to send terminal init. But don't need this
 279                  * if -X (no_init) overrides this (see init()).
 280                  */
 281                 if (quit_if_one_screen)
 282                 {
 283                         if (nifile() > 1) /* If more than one file, -F cannot be used */
 284                                 quit_if_one_screen = FALSE;
 285                         else if (!no_init)
 286                                 one_screen = get_one_screen();
 287                 }
 288         }
 289
 290         if (errmsgs > 0)
 291         {
 292                 /*
 293                  * We displayed some messages on error output
 294                  * (file descriptor 2; see flush()).
 295                  * Before erasing the screen contents, wait for a keystroke.
 296                  */
 297                 less_printf("Press RETURN to continue ", NULL_PARG);
 298                 get_return();
 299                 putchr('\n');
 300         }
 301         set_output(1);
 302         init();
 303         commands();
 304         quit(QUIT_OK);
 305         /*NOTREACHED*/
 306         return (0);
 307 }
 308
 309 /*
 310  * Copy a string to a "safe" place
 311  * (that is, to a buffer allocated by calloc).
 312  */
 313 public char * save(constant char *s)
 314 {
 315         char *p;
 316
 317         p = (char *) ecalloc(strlen(s)+1, sizeof(char));
 318         strcpy(p, s);
 319         return (p);
 320 }
 321
 322 public void out_of_memory(void)
 323 {
 324         error("Cannot allocate memory", NULL_PARG);
 325         quit(QUIT_ERROR);
 326 }
 327
 328 /*
 329  * Allocate memory.
 330  * Like calloc(), but never returns an error (NULL).
 331  */
 332 public void * ecalloc(int count, unsigned int size)
 333 {
 334         void * p;
 335
 336         p = (void *) calloc(count, size);
 337         if (p == NULL)
 338                 out_of_memory();
 339         return p;
 340 }
 341
 342 /*
 343  * Skip leading spaces in a string.
 344  */
 345 public char * skipsp(char *s)
 346 {
 347         while (*s == ' ' || *s == '\t')
 348                 s++;
 349         return (s);
 350 }
 351
 352 /*
 353  * See how many characters of two strings are identical.
 354  * If uppercase is true, the first string must begin with an uppercase
 355  * character; the remainder of the first string may be either case.
 356  */
 357 public int sprefix(char *ps, char *s, int uppercase)
 358 {
 359         int c;
 360         int sc;
 361         int len = 0;
 362
 363         for ( ;  *s != '\0';  s++, ps++)
 364         {
 365                 c = *ps;
 366                 if (uppercase)
 367                 {
 368                         if (len == 0 && ASCII_IS_LOWER(c))
 369                                 return (-1);
 370                         if (ASCII_IS_UPPER(c))
 371                                 c = ASCII_TO_LOWER(c);
 372                 }
 373                 sc = *s;
 374                 if (len > 0 && ASCII_IS_UPPER(sc))
 375                         sc = ASCII_TO_LOWER(sc);
 376                 if (c != sc)
 377                         break;
 378                 len++;
 379         }
 380         return (len);
 381 }
 382
 383 /*
 384  * Exit the program.
 385  */
 386 public void quit(int status)
 387 {
 388         static int save_status;
 389
 390         /*
 391          * Put cursor at bottom left corner, clear the line,
 392          * reset the terminal modes, and exit.
 393          */
 394         if (status < 0)
 395                 status = save_status;
 396         else
 397                 save_status = status;
 398         quitting = 1;
 399         check_altpipe_error();
 400         if (interactive())
 401                 clear_bot();
 402         deinit();
 403         flush();
 404         if (redraw_on_quit && term_init_done)
 405         {
 406                 /*
 407                  * The last file text displayed might have been on an
 408                  * alternate screen, which now (since deinit) cannot be seen.
 409                  * redraw_on_quit tells us to redraw it on the main screen.
 410                  */
 411                 first_time = 1; /* Don't print "skipping" or tildes */
 412                 repaint();
 413                 flush();
 414         }
 415         edit((char*)NULL);
 416         save_cmdhist();
 417         raw_mode(0);
 418 #if MSDOS_COMPILER && MSDOS_COMPILER != DJGPPC
 419         /*
 420          * If we don't close 2, we get some garbage from
 421          * 2's buffer when it flushes automatically.
 422          * I cannot track this one down  RB
 423          * The same bug shows up if we use ^C^C to abort.
 424          */
 425         close(2);
 426 #endif
 427 #ifdef WIN32
 428         SetConsoleTitle(consoleTitle);
 429 #endif
 430         close_getchr();
 431         exit(status);
 432 }