src/termcap.c

   1 /* Work-alike for termcap, plus extra features.
   2    Copyright (C) 1985, 1986, 1993, 1994, 1995, 2000, 2001, 2002, 2003,
   3                  2004, 2005, 2006, 2007, 2008 Free Software Foundation, Inc.
   4
   5 This program is free software; you can redistribute it and/or modify
   6 it under the terms of the GNU General Public License as published by
   7 the Free Software Foundation; either version 2, or (at your option)
   8 any later version.
   9
  10 This program is distributed in the hope that it will be useful,
  11 but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 GNU General Public License for more details.
  14
  15 You should have received a copy of the GNU General Public License
  16 along with this program; see the file COPYING.  If not, write to
  17 the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  18 Boston, MA 02110-1301, USA.  */
  19
  20 /* Emacs config.h may rename various library functions such as malloc.  */
  21 #include <config.h>
  22 #include <setjmp.h>
  23 #include <sys/file.h>
  24 #include <fcntl.h>
  25 #include <unistd.h>
  26
  27 #include "lisp.h"
  28 #include "tparam.h"
  29 #ifdef MSDOS
  30 #include "msdos.h"
  31 #endif
  32
  33 #ifndef NULL
  34 #define NULL (char *) 0
  35 #endif
  36
  37 /* BUFSIZE is the initial size allocated for the buffer
  38    for reading the termcap file.
  39    It is not a limit.
  40    Make it large normally for speed.
  41    Make it variable when debugging, so can exercise
  42    increasing the space dynamically.  */
  43
  44 #ifndef BUFSIZE
  45 #ifdef DEBUG
  46 #define BUFSIZE bufsize
  47
  48 int bufsize = 128;
  49 #else
  50 #define BUFSIZE 2048
  51 #endif
  52 #endif
  53
  54 #ifndef TERMCAP_FILE
  55 #define TERMCAP_FILE "/etc/termcap"
  56 #endif
  57
  58 \f
  59 /* Looking up capabilities in the entry already found.  */
  60
  61 /* The pointer to the data made by tgetent is left here
  62    for tgetnum, tgetflag and tgetstr to find.  */
  63 static char *term_entry;
  64
  65 static char *tgetst1 (char *ptr, char **area);
  66
  67 /* Search entry BP for capability CAP.
  68    Return a pointer to the capability (in BP) if found,
  69    0 if not found.  */
  70
  71 static char *
  72 find_capability (register char *bp, register const char *cap)
  73 {
  74   for (; *bp; bp++)
  75     if (bp[0] == ':'
  76         && bp[1] == cap[0]
  77         && bp[2] == cap[1])
  78       return &bp[4];
  79   return NULL;
  80 }
  81
  82 int
  83 tgetnum (const char *cap)
  84 {
  85   register char *ptr = find_capability (term_entry, cap);
  86   if (!ptr || ptr[-1] != '#')
  87     return -1;
  88   return atoi (ptr);
  89 }
  90
  91 int
  92 tgetflag (const char *cap)
  93 {
  94   register char *ptr = find_capability (term_entry, cap);
  95   return ptr && ptr[-1] == ':';
  96 }
  97
  98 /* Look up a string-valued capability CAP.
  99    If AREA is non-null, it points to a pointer to a block in which
 100    to store the string.  That pointer is advanced over the space used.
 101    If AREA is null, space is allocated with `malloc'.  */
 102
 103 char *
 104 tgetstr (const char *cap, char **area)
 105 {
 106   register char *ptr = find_capability (term_entry, cap);
 107   if (!ptr || (ptr[-1] != '=' && ptr[-1] != '~'))
 108     return NULL;
 109   return tgetst1 (ptr, area);
 110 }
 111
 112 #ifdef IS_EBCDIC_HOST
 113 /* Table, indexed by a character in range 0200 to 0300 with 0200 subtracted,
 114    gives meaning of character following \, or a space if no special meaning.
 115    Sixteen characters per line within the string.  */
 116
 117 static const char esctab[]
 118   = " \057\026  \047\014         \
 119      \025   \015      \
 120    \005 \013          \
 121                 ";
 122 #else
 123 /* Table, indexed by a character in range 0100 to 0140 with 0100 subtracted,
 124    gives meaning of character following \, or a space if no special meaning.
 125    Eight characters per line within the string.  */
 126
 127 static const char esctab[]
 128   = " \007\010  \033\014 \
 129       \012 \
 130   \015 \011 \013 \
 131         ";
 132 #endif
 133
 134 /* PTR points to a string value inside a termcap entry.
 135    Copy that value, processing \ and ^ abbreviations,
 136    into the block that *AREA points to,
 137    or to newly allocated storage if AREA is NULL.
 138    Return the address to which we copied the value,
 139    or NULL if PTR is NULL.  */
 140
 141 static char *
 142 tgetst1 (char *ptr, char **area)
 143 {
 144   register char *p, *r;
 145   register int c;
 146   register int size;
 147   char *ret;
 148   register int c1;
 149
 150   if (!ptr)
 151     return NULL;
 152
 153   /* `ret' gets address of where to store the string.  */
 154   if (!area)
 155     {
 156       /* Compute size of block needed (may overestimate).  */
 157       p = ptr;
 158       while ((c = *p++) && c != ':' && c != '\n')
 159         ;
 160       ret = (char *) xmalloc (p - ptr + 1);
 161     }
 162   else
 163     ret = *area;
 164
 165   /* Copy the string value, stopping at null or colon.
 166      Also process ^ and \ abbreviations.  */
 167   p = ptr;
 168   r = ret;
 169   while ((c = *p++) && c != ':' && c != '\n')
 170     {
 171       if (c == '^')
 172         {
 173           c = *p++;
 174           if (c == '?')
 175             c = 0177;
 176           else
 177             c &= 037;
 178         }
 179       else if (c == '\\')
 180         {
 181           c = *p++;
 182           if (c >= '0' && c <= '7')
 183             {
 184               c -= '0';
 185               size = 0;
 186
 187               while (++size < 3 && (c1 = *p) >= '0' && c1 <= '7')
 188                 {
 189                   c *= 8;
 190                   c += c1 - '0';
 191                   p++;
 192                 }
 193             }
 194 #ifdef IS_EBCDIC_HOST
 195           else if (c >= 0200 && c < 0360)
 196             {
 197               c1 = esctab[(c & ~0100) - 0200];
 198               if (c1 != ' ')
 199                 c = c1;
 200             }
 201 #else
 202           else if (c >= 0100 && c < 0200)
 203             {
 204               c1 = esctab[(c & ~040) - 0100];
 205               if (c1 != ' ')
 206                 c = c1;
 207             }
 208 #endif
 209         }
 210       *r++ = c;
 211     }
 212
 213   /* Sometimes entries have "%pN" which means use parameter N in the
 214      next %-substitution.  If all such N are continuous in the range
 215      [1,9] we can remove each "%pN" because they are redundant, thus
 216      reducing bandwidth requirements.  True, Emacs is well beyond the
 217      days of 150baud teletypes, but some of its users aren't much so.
 218
 219      This pass could probably be integrated into the one above but
 220      abbreviation expansion makes that effort a little more hairy than
 221      its worth; this is cleaner.  */
 222   {
 223     register int last_p_param = 0;
 224     int remove_p_params = 1;
 225     struct { char *beg; int len; } cut[11];
 226
 227     for (cut[0].beg = p = ret; p < r - 3; p++)
 228       {
 229         if (!remove_p_params)
 230           break;
 231         if (*p == '%' && *(p + 1) == 'p')
 232           {
 233             if (*(p + 2) - '0' == 1 + last_p_param)
 234               {
 235                 cut[last_p_param].len = p - cut[last_p_param].beg;
 236                 last_p_param++;
 237                 p += 3;
 238                 cut[last_p_param].beg = p;
 239               }
 240             else                                /* not continuous: bail */
 241               remove_p_params = 0;
 242             if (last_p_param > 10)              /* too many: bail */
 243               remove_p_params = 0;
 244           }
 245       }
 246     if (remove_p_params && last_p_param)
 247       {
 248         register int i;
 249         char *wp;
 250
 251         cut[last_p_param].len = r - cut[last_p_param].beg;
 252         for (i = 0, wp = ret; i <= last_p_param; wp += cut[i++].len)
 253           memcpy (wp, cut[i].beg, cut[i].len);
 254         r = wp;
 255       }
 256   }
 257
 258   *r = '\0';
 259   /* Update *AREA.  */
 260   if (area)
 261     *area = r + 1;
 262   return ret;
 263 }
 264 \f
 265 /* Outputting a string with padding.  */
 266
 267 char PC;
 268
 269 void
 270 tputs (register const char *str, int nlines, int (*outfun) (int))
 271 {
 272   register int padcount = 0;
 273   register int speed;
 274
 275   speed = baud_rate;
 276   /* For quite high speeds, convert to the smaller
 277      units to avoid overflow.  */
 278   if (speed > 10000)
 279     speed = - speed / 100;
 280
 281   if (!str)
 282     return;
 283
 284   while (*str >= '0' && *str <= '9')
 285     {
 286       padcount += *str++ - '0';
 287       padcount *= 10;
 288     }
 289   if (*str == '.')
 290     {
 291       str++;
 292       padcount += *str++ - '0';
 293     }
 294   if (*str == '*')
 295     {
 296       str++;
 297       padcount *= nlines;
 298     }
 299   while (*str)
 300     (*outfun) (*str++);
 301
 302   /* PADCOUNT is now in units of tenths of msec.
 303      SPEED is measured in characters per 10 seconds
 304      or in characters per .1 seconds (if negative).
 305      We use the smaller units for larger speeds to avoid overflow.  */
 306   padcount *= speed;
 307   padcount += 500;
 308   padcount /= 1000;
 309   if (speed < 0)
 310     padcount = -padcount;
 311   else
 312     {
 313       padcount += 50;
 314       padcount /= 100;
 315     }
 316
 317   while (padcount-- > 0)
 318     (*outfun) (PC);
 319 }
 320 \f
 321 /* Finding the termcap entry in the termcap data base.  */
 322
 323 struct termcap_buffer
 324   {
 325     char *beg;
 326     int size;
 327     char *ptr;
 328     int ateof;
 329     int full;
 330   };
 331
 332 /* Forward declarations of static functions.  */
 333
 334 static int scan_file (char *str, int fd, register struct termcap_buffer *bufp);
 335 static char *gobble_line (int fd, register struct termcap_buffer *bufp, char *append_end);
 336 static int compare_contin (register char *str1, register char *str2);
 337 static int name_match (char *line, char *name);
 338
 339 #ifdef MSDOS /* MW, May 1993 */
 340 static int
 341 valid_filename_p (fn)
 342      char *fn;
 343 {
 344   return *fn == '/' || fn[1] == ':';
 345 }
 346 #else
 347 #define valid_filename_p(fn) (*(fn) == '/')
 348 #endif
 349
 350 /* Find the termcap entry data for terminal type NAME
 351    and store it in the block that BP points to.
 352    Record its address for future use.
 353
 354    If BP is null, space is dynamically allocated.
 355
 356    Return -1 if there is some difficulty accessing the data base
 357    of terminal types,
 358    0 if the data base is accessible but the type NAME is not defined
 359    in it, and some other value otherwise.  */
 360
 361 int
 362 tgetent (char *bp, const char *name)
 363 {
 364   register char *termcap_name;
 365   register int fd;
 366   struct termcap_buffer buf;
 367   register char *bp1;
 368   char *tc_search_point;
 369   char *term;
 370   int malloc_size = 0;
 371   register int c;
 372   char *tcenv = NULL;           /* TERMCAP value, if it contains :tc=.  */
 373   char *indirect = NULL;        /* Terminal type in :tc= in TERMCAP value.  */
 374   int filep;
 375
 376 #ifdef INTERNAL_TERMINAL
 377   /* For the internal terminal we don't want to read any termcap file,
 378      so fake it.  */
 379   if (!strcmp (name, "internal"))
 380     {
 381       term = INTERNAL_TERMINAL;
 382       if (!bp)
 383         {
 384           malloc_size = 1 + strlen (term);
 385           bp = (char *) xmalloc (malloc_size);
 386         }
 387       strcpy (bp, term);
 388       goto ret;
 389     }
 390 #endif /* INTERNAL_TERMINAL */
 391
 392   /* For compatibility with programs like `less' that want to
 393      put data in the termcap buffer themselves as a fallback.  */
 394   if (bp)
 395     term_entry = bp;
 396
 397   termcap_name = getenv ("TERMCAP");
 398   if (termcap_name && *termcap_name == '\0')
 399     termcap_name = NULL;
 400 #if defined (MSDOS) && !defined (TEST)
 401   if (termcap_name && (*termcap_name == '\\'
 402                        || *termcap_name == '/'
 403                        || termcap_name[1] == ':'))
 404     dostounix_filename(termcap_name);
 405 #endif
 406
 407   filep = termcap_name && valid_filename_p (termcap_name);
 408
 409   /* If termcap_name is non-null and starts with / (in the un*x case, that is),
 410      it is a file name to use instead of /etc/termcap.
 411      If it is non-null and does not start with /,
 412      it is the entry itself, but only if
 413      the name the caller requested matches the TERM variable.  */
 414
 415   if (termcap_name && !filep && !strcmp (name, getenv ("TERM")))
 416     {
 417       indirect = tgetst1 (find_capability (termcap_name, "tc"), (char **) 0);
 418       if (!indirect)
 419         {
 420           if (!bp)
 421             bp = termcap_name;
 422           else
 423             strcpy (bp, termcap_name);
 424           goto ret;
 425         }
 426       else
 427         {                       /* It has tc=.  Need to read /etc/termcap.  */
 428           tcenv = termcap_name;
 429           termcap_name = NULL;
 430         }
 431     }
 432
 433   if (!termcap_name || !filep)
 434     termcap_name = TERMCAP_FILE;
 435
 436   /* Here we know we must search a file and termcap_name has its name.  */
 437
 438 #ifdef MSDOS
 439   fd = open (termcap_name, O_RDONLY|O_TEXT, 0);
 440 #else
 441   fd = open (termcap_name, O_RDONLY, 0);
 442 #endif
 443   if (fd < 0)
 444     return -1;
 445
 446   buf.size = BUFSIZE;
 447   /* Add 1 to size to ensure room for terminating null.  */
 448   buf.beg = (char *) xmalloc (buf.size + 1);
 449   term = indirect ? indirect : (char *)name;
 450
 451   if (!bp)
 452     {
 453       malloc_size = indirect ? strlen (tcenv) + 1 : buf.size;
 454       bp = (char *) xmalloc (malloc_size);
 455     }
 456   tc_search_point = bp1 = bp;
 457
 458   if (indirect)
 459     /* Copy the data from the environment variable.  */
 460     {
 461       strcpy (bp, tcenv);
 462       bp1 += strlen (tcenv);
 463     }
 464
 465   while (term)
 466     {
 467       /* Scan the file, reading it via buf, till find start of main entry.  */
 468       if (scan_file (term, fd, &buf) == 0)
 469         {
 470           close (fd);
 471           free (buf.beg);
 472           if (malloc_size)
 473             free (bp);
 474           return 0;
 475         }
 476
 477       /* Free old `term' if appropriate.  */
 478       if (term != name)
 479         free (term);
 480
 481       /* If BP is malloc'd by us, make sure it is big enough.  */
 482       if (malloc_size)
 483         {
 484           int offset1 = bp1 - bp, offset2 = tc_search_point - bp;
 485           malloc_size = offset1 + buf.size;
 486           bp = termcap_name = (char *) xrealloc (bp, malloc_size);
 487           bp1 = termcap_name + offset1;
 488           tc_search_point = termcap_name + offset2;
 489         }
 490
 491       /* Copy the line of the entry from buf into bp.  */
 492       termcap_name = buf.ptr;
 493       while ((*bp1++ = c = *termcap_name++) && c != '\n')
 494         /* Drop out any \ newline sequence.  */
 495         if (c == '\\' && *termcap_name == '\n')
 496           {
 497             bp1--;
 498             termcap_name++;
 499           }
 500       *bp1 = '\0';
 501
 502       /* Does this entry refer to another terminal type's entry?
 503          If something is found, copy it into heap and null-terminate it.  */
 504       tc_search_point = find_capability (tc_search_point, "tc");
 505       term = tgetst1 (tc_search_point, (char **) 0);
 506     }
 507
 508   close (fd);
 509   free (buf.beg);
 510
 511   if (malloc_size)
 512     bp = (char *) xrealloc (bp, bp1 - bp + 1);
 513
 514  ret:
 515   term_entry = bp;
 516   return 1;
 517 }
 518
 519 /* Given file open on FD and buffer BUFP,
 520    scan the file from the beginning until a line is found
 521    that starts the entry for terminal type STR.
 522    Return 1 if successful, with that line in BUFP,
 523    or 0 if no entry is found in the file.  */
 524
 525 static int
 526 scan_file (char *str, int fd, register struct termcap_buffer *bufp)
 527 {
 528   register char *end;
 529
 530   bufp->ptr = bufp->beg;
 531   bufp->full = 0;
 532   bufp->ateof = 0;
 533   *bufp->ptr = '\0';
 534
 535   lseek (fd, 0L, 0);
 536
 537   while (!bufp->ateof)
 538     {
 539       /* Read a line into the buffer.  */
 540       end = NULL;
 541       do
 542         {
 543           /* if it is continued, append another line to it,
 544              until a non-continued line ends.  */
 545           end = gobble_line (fd, bufp, end);
 546         }
 547       while (!bufp->ateof && end[-2] == '\\');
 548
 549       if (*bufp->ptr != '#'
 550           && name_match (bufp->ptr, str))
 551         return 1;
 552
 553       /* Discard the line just processed.  */
 554       bufp->ptr = end;
 555     }
 556   return 0;
 557 }
 558
 559 /* Return nonzero if NAME is one of the names specified
 560    by termcap entry LINE.  */
 561
 562 static int
 563 name_match (char *line, char *name)
 564 {
 565   register char *tem;
 566
 567   if (!compare_contin (line, name))
 568     return 1;
 569   /* This line starts an entry.  Is it the right one?  */
 570   for (tem = line; *tem && *tem != '\n' && *tem != ':'; tem++)
 571     if (*tem == '|' && !compare_contin (tem + 1, name))
 572       return 1;
 573
 574   return 0;
 575 }
 576
 577 static int
 578 compare_contin (register char *str1, register char *str2)
 579 {
 580   register int c1, c2;
 581   while (1)
 582     {
 583       c1 = *str1++;
 584       c2 = *str2++;
 585       while (c1 == '\\' && *str1 == '\n')
 586         {
 587           str1++;
 588           while ((c1 = *str1++) == ' ' || c1 == '\t');
 589         }
 590       if (c2 == '\0')
 591         {
 592           /* End of type being looked up.  */
 593           if (c1 == '|' || c1 == ':')
 594             /* If end of name in data base, we win.  */
 595             return 0;
 596           else
 597             return 1;
 598         }
 599       else if (c1 != c2)
 600         return 1;
 601     }
 602 }
 603
 604 /* Make sure that the buffer <- BUFP contains a full line
 605    of the file open on FD, starting at the place BUFP->ptr
 606    points to.  Can read more of the file, discard stuff before
 607    BUFP->ptr, or make the buffer bigger.
 608
 609    Return the pointer to after the newline ending the line,
 610    or to the end of the file, if there is no newline to end it.
 611
 612    Can also merge on continuation lines.  If APPEND_END is
 613    non-null, it points past the newline of a line that is
 614    continued; we add another line onto it and regard the whole
 615    thing as one line.  The caller decides when a line is continued.  */
 616
 617 static char *
 618 gobble_line (int fd, register struct termcap_buffer *bufp, char *append_end)
 619 {
 620   register char *end;
 621   register int nread;
 622   register char *buf = bufp->beg;
 623   register char *tem;
 624
 625   if (!append_end)
 626     append_end = bufp->ptr;
 627
 628   while (1)
 629     {
 630       end = append_end;
 631       while (*end && *end != '\n') end++;
 632       if (*end)
 633         break;
 634       if (bufp->ateof)
 635         return buf + bufp->full;
 636       if (bufp->ptr == buf)
 637         {
 638           if (bufp->full == bufp->size)
 639             {
 640               bufp->size *= 2;
 641               /* Add 1 to size to ensure room for terminating null.  */
 642               tem = (char *) xrealloc (buf, bufp->size + 1);
 643               bufp->ptr = (bufp->ptr - buf) + tem;
 644               append_end = (append_end - buf) + tem;
 645               bufp->beg = buf = tem;
 646             }
 647         }
 648       else
 649         {
 650           append_end -= bufp->ptr - buf;
 651           memcpy (buf, bufp->ptr, bufp->full -= bufp->ptr - buf);
 652           bufp->ptr = buf;
 653         }
 654       if (!(nread = read (fd, buf + bufp->full, bufp->size - bufp->full)))
 655         bufp->ateof = 1;
 656       bufp->full += nread;
 657       buf[bufp->full] = '\0';
 658     }
 659   return end + 1;
 660 }
 661 \f
 662 #ifdef TEST
 663
 664 #ifdef NULL
 665 #undef NULL
 666 #endif
 667
 668 #include <stdio.h>
 669
 670 main (argc, argv)
 671      int argc;
 672      char **argv;
 673 {
 674   char *term;
 675   char *buf;
 676
 677   term = argv[1];
 678   printf ("TERM: %s\n", term);
 679
 680   buf = (char *) tgetent (0, term);
 681   if ((int) buf <= 0)
 682     {
 683       printf ("No entry.\n");
 684       return 0;
 685     }
 686
 687   printf ("Entry: %s\n", buf);
 688
 689   tprint ("cm");
 690   tprint ("AL");
 691
 692   printf ("co: %d\n", tgetnum ("co"));
 693   printf ("am: %d\n", tgetflag ("am"));
 694 }
 695
 696 tprint (cap)
 697      char *cap;
 698 {
 699   char *x = tgetstr (cap, 0);
 700   register char *y;
 701
 702   printf ("%s: ", cap);
 703   if (x)
 704     {
 705       for (y = x; *y; y++)
 706         if (*y <= ' ' || *y == 0177)
 707           printf ("\\%0o", *y);
 708         else
 709           putchar (*y);
 710       free (x);
 711     }
 712   else
 713     printf ("none");
 714   putchar ('\n');
 715 }
 716
 717 #endif /* TEST */
 718