diplodocus.org Git - nmh/blob - docs/historical/mh-6.8.5/miscellany/less-177/main.c

   1 /*
   2  * Entry point, initialization, miscellaneous routines.
   3  */
   4
   5 #include "less.h"
   6 #include "position.h"
   7
   8 public int      ispipe;
   9 public char *   every_first_cmd = NULL;
  10 public int      new_file;
  11 public int      is_tty;
  12 public IFILE    curr_ifile = NULL_IFILE;
  13 public IFILE    old_ifile = NULL_IFILE;
  14 public struct scrpos initial_scrpos;
  15 public int      any_display = 0;
  16 public int      scroll;
  17 public char *   progname;
  18 public int      quitting;
  19
  20 extern int      file;
  21 extern int      quit_at_eof;
  22 extern int      cbufs;
  23 extern int      errmsgs;
  24 extern int      screen_trashed;
  25 extern int      force_open;
  26
  27 #if LOGFILE
  28 public int      logfile = -1;
  29 public int      force_logfile = 0;
  30 public char *   namelogfile = NULL;
  31 #endif
  32
  33 #if EDITOR
  34 public char *   editor;
  35 public char *   editproto;
  36 #endif
  37
  38 #if TAGS
  39 extern char *   tagfile;
  40 extern char *   tagpattern;
  41 extern int      tagoption;
  42 #endif
  43
  44
  45
  46 /*
  47  * Entry point.
  48  */
  49 main(argc, argv)
  50         int argc;
  51         char *argv[];
  52 {
  53         IFILE h;
  54         int nofiles;
  55         extern char *getenv();
  56
  57         progname = *argv++;
  58
  59         /*
  60          * Process command line arguments and LESS environment arguments.
  61          * Command line arguments override environment arguments.
  62          */
  63         init_prompt();
  64         init_charset();
  65         init_option();
  66         scan_option(getenv("LESS"));
  67
  68 #define isoptstring(s)  (((s)[0] == '-' || (s)[0] == '+') && (s)[1] != '\0')
  69         while (--argc > 0 && (isoptstring(argv[0]) || isoptpending()))
  70                 scan_option(*argv++);
  71 #undef isoptstring
  72
  73         if (isoptpending())
  74         {
  75                 /*
  76                  * Last command line option was a flag requiring a
  77                  * following string, but there was no following string.
  78                  */
  79                 nopendopt();
  80                 quit(0);
  81         }
  82
  83 #if USERFILE
  84         /*
  85          * Try to use the lesskey file "$HOME/.less".
  86          */
  87         add_hometable();
  88 #endif
  89 #if EDITOR
  90         editor = getenv("EDITOR");
  91         if (editor == NULL || *editor == '\0')
  92                 editor = EDIT_PGM;
  93         editproto = getenv("LESSEDIT");
  94         if (editproto == NULL || *editproto == '\0')
  95                 editproto = "%E ?lm+%lm. %f";
  96 #endif
  97
  98         /*
  99          * Set up terminal, etc.
 100          */
 101         is_tty = isatty(1);
 102         if (!is_tty)
 103         {
 104                 /*
 105                  * Output is not a tty.
 106                  * Just copy the input file(s) to output.
 107                  */
 108                 if (argc <= 0)
 109                 {
 110                         if (edit("-", 0) == 0)
 111                                 cat_file();
 112                 } else
 113                 {
 114                         while (--argc >= 0)
 115                         {
 116                                 if (edit(*argv++, 0) == 0)
 117                                         cat_file();
 118                         }
 119                 }
 120                 quit(0);
 121         }
 122
 123         /*
 124          * Call get_ifile with all the command line filenames
 125          * to "register" them with the ifile system.
 126          */
 127         h = NULL_IFILE;
 128         while (--argc >= 0)
 129                 h = get_ifile(*argv++, h);
 130
 131         init_mark();
 132         raw_mode(1);
 133         get_term();
 134         open_getchr();
 135
 136         init_signals(1);
 137
 138         /*
 139          * Select the first file to examine.
 140          */
 141 #if TAGS
 142         if (tagoption)
 143         {
 144                 /*
 145                  * A -t option was given.
 146                  * Verify that no filenames were also given.
 147                  * Edit the file selected by the "tags" search,
 148                  * and search for the proper line in the file.
 149                  */
 150                 if (nifile() > 0)
 151                 {
 152                         error("No filenames allowed with -t option", NULL_PARG);
 153                         quit(1);
 154                 }
 155                 if (tagfile == NULL)
 156                         quit(1);
 157                 if (edit(tagfile, 0) || tagsearch())
 158                         quit(1);
 159                 nofiles = 0;
 160         } else
 161 #endif
 162         if (nifile() == 0)
 163                 nofiles = edit("-", 0); /* Standard input */
 164         else
 165                 nofiles = edit_first();
 166
 167         if (nofiles)
 168         {
 169                 quit(1);
 170                 /*NOTREACHED*/
 171         }
 172
 173         init();
 174         commands();
 175         quit(0);
 176         /*NOTREACHED*/
 177 }
 178
 179 /*
 180  * Copy a string, truncating to the specified length if necessary.
 181  * Unlike strncpy(), the resulting string is guaranteed to be null-terminated.
 182  */
 183         public void
 184 strtcpy(to, from, len)
 185         char *to;
 186         char *from;
 187         unsigned int len;
 188 {
 189         strncpy(to, from, len);
 190         to[len-1] = '\0';
 191 }
 192
 193 /*
 194  * Copy a string to a "safe" place
 195  * (that is, to a buffer allocated by calloc).
 196  */
 197         public char *
 198 save(s)
 199         char *s;
 200 {
 201         register char *p;
 202
 203         p = (char *) ecalloc(strlen(s)+1, sizeof(char));
 204         strcpy(p, s);
 205         return (p);
 206 }
 207
 208         public VOID_POINTER
 209 ecalloc(count, size)
 210         int count;
 211         unsigned int size;
 212 {
 213         register VOID_POINTER p;
 214
 215         p = calloc(count, size);
 216         if (p != NULL)
 217                 return (p);
 218         error("Cannot allocate memory", NULL_PARG);
 219         quit(1);
 220         /*NOTREACHED*/
 221 }
 222
 223 /*
 224  * Skip leading spaces in a string.
 225  */
 226         public char *
 227 skipsp(s)
 228         register char *s;
 229 {
 230         while (*s == ' ' || *s == '\t')
 231                 s++;
 232         return (s);
 233 }
 234
 235 /*
 236  * Exit the program.
 237  */
 238         public void
 239 quit(status)
 240         int status;
 241 {
 242         static int save_status;
 243
 244         /*
 245          * Put cursor at bottom left corner, clear the line,
 246          * reset the terminal modes, and exit.
 247          */
 248         if (status < 0)
 249                 status = save_status;
 250         else
 251                 save_status = status;
 252         quitting = 1;
 253 #if LOGFILE
 254         end_logfile();
 255 #endif
 256         if (any_display)
 257         {
 258                 lower_left();
 259                 clear_eol();
 260         }
 261         deinit();
 262         flush();
 263         raw_mode(0);
 264 #if __MSDOS__
 265         restore_screen();
 266         /*
 267          * If we don't close 2, we get some garbage from
 268          * 2's buffer when it flushes automatically.
 269          * I cannot track this one down  RB
 270          * The same bug shows up if we use ^C^C to abort.
 271          */
 272         close(2);
 273 #endif
 274         exit(status);
 275 }