pith/escapes.c

   1 #if !defined(lint) && !defined(DOS)
   2 static char rcsid[] = "$Id: escapes.c 761 2007-10-23 22:35:18Z hubert@u.washington.edu $";
   3 #endif
   4
   5 /*
   6  * ========================================================================
   7  * Copyright 2006 University of Washington
   8  *
   9  * Licensed under the Apache License, Version 2.0 (the "License");
  10  * you may not use this file except in compliance with the License.
  11  * You may obtain a copy of the License at
  12  *
  13  *     http://www.apache.org/licenses/LICENSE-2.0
  14  *
  15  * ========================================================================
  16  */
  17
  18 /*======================================================================
  19
  20      escapes.c
  21      Implements known escape code matching
  22
  23   ====*/
  24
  25
  26 #include "../pith/headers.h"
  27 #include "../pith/escapes.h"
  28
  29
  30
  31 /*------------------------------------------------------------------
  32    This list of known escape sequences is taken from RFC's 1486 and 1554
  33    and draft-apng-cc-encoding, and the X11R5 source with only a remote
  34    understanding of what this all means...
  35
  36    NOTE: if the length of these should extend beyond 4 chars, fix
  37          MAX_ESC_LEN in filter.c
  38   ----*/
  39 #ifdef  _WINDOWS
  40 static char *known_escapes[] = {
  41     "(B",  "(J",  "$@",  "$B",                  /* RFC 1468 */
  42     "(H",
  43     NULL};
  44 #else
  45 static char *known_escapes[] = {
  46     "(B",  "(J",  "$@",  "$B",                  /* RFC 1468 */
  47     "(H",
  48     "$A",  "$(C", "$(D", ".A",  ".F",           /* added by RFC 1554 */
  49     "$)C", "$)A", "$*E", "$*X",                 /* those in apng-draft */
  50     "$+G", "$+H", "$+I", "$+J", "$+K",
  51     "$+L", "$+M",
  52     ")I",   "-A",  "-B",  "-C",  "-D",          /* codes form X11R5 source */
  53     "-F",   "-G",  "-H",   "-L",  "-M",
  54     "-$(A", "$(B", "$)B", "$)D",
  55     NULL};
  56 #endif
  57
  58
  59 int
  60 match_escapes(char *esc_seq)
  61 {
  62     char **p;
  63     int    n;
  64
  65     for(p = known_escapes; *p && strncmp(esc_seq, *p, n = strlen(*p)); p++)
  66       ;
  67
  68     return(*p ? n + 1 : 0);
  69 }