1: /*
   2:  * Copyright (c) 1980 Regents of the University of California.
   3:  * All rights reserved.  The Berkeley software License Agreement
   4:  * specifies the terms and conditions for redistribution.
   5:  */
   6: 
   7: #if !defined(lint) && !defined(NOSCCS)
   8: static char sccsid[] = "@(#)tgoto.c	5.1 (Berkeley) 6/5/85";
   9: #endif not lint
  10: 
  11: #define CTRL(c) ('c' & 037)
  12: 
  13: #define MAXRETURNSIZE 64
  14: 
  15: char    *UP;
  16: char    *BC;
  17: 
  18: /*
  19:  * Routine to perform cursor addressing.
  20:  * CM is a string containing printf type escapes to allow
  21:  * cursor addressing.  We start out ready to print the destination
  22:  * line, and switch each time we print row or column.
  23:  * The following escapes are defined for substituting row/column:
  24:  *
  25:  *	%d	as in printf
  26:  *	%2	like %2d
  27:  *	%3	like %3d
  28:  *	%.	gives %c hacking special case characters
  29:  *	%+x	like %c but adding x first
  30:  *
  31:  *	The codes below affect the state but don't use up a value.
  32:  *
  33:  *	%>xy	if value > x add y
  34:  *	%r	reverses row/column
  35:  *	%i	increments row/column (for one origin indexing)
  36:  *	%%	gives %
  37:  *	%B	BCD (2 decimal digits encoded in one byte)
  38:  *	%D	Delta Data (backwards bcd)
  39:  *
  40:  * all other characters are ``self-inserting''.
  41:  */
  42: char *
  43: tgoto(CM, destcol, destline)
  44:     char *CM;
  45:     int destcol, destline;
  46: {
  47:     static char result[MAXRETURNSIZE];
  48:     static char added[10];
  49:     char *cp = CM;
  50:     register char *dp = result;
  51:     register int c;
  52:     int oncol = 0;
  53:     register int which = destline;
  54: 
  55:     if (cp == 0) {
  56: toohard:
  57:         /*
  58: 		 * ``We don't do that under BOZO's big top''
  59: 		 */
  60:         return ("OOPS");
  61:     }
  62:     added[0] = 0;
  63:     while (c = *cp++) {
  64:         if (c != '%') {
  65:             *dp++ = c;
  66:             continue;
  67:         }
  68:         switch (c = *cp++) {
  69: 
  70: #ifdef CM_N
  71:         case 'n':
  72:             destcol ^= 0140;
  73:             destline ^= 0140;
  74:             goto setwhich;
  75: #endif
  76: 
  77:         case 'd':
  78:             if (which < 10)
  79:                 goto one;
  80:             if (which < 100)
  81:                 goto two;
  82:             /* fall into... */
  83: 
  84:         case '3':
  85:             *dp++ = (which / 100) | '0';
  86:             which %= 100;
  87:             /* fall into... */
  88: 
  89:         case '2':
  90: two:
  91:             *dp++ = which / 10 | '0';
  92: one:
  93:             *dp++ = which % 10 | '0';
  94: swap:
  95:             oncol = 1 - oncol;
  96: setwhich:
  97:             which = oncol ? destcol : destline;
  98:             continue;
  99: 
 100: #ifdef CM_GT
 101:         case '>':
 102:             if (which > *cp++)
 103:                 which += *cp++;
 104:             else
 105:                 cp++;
 106:             continue;
 107: #endif
 108: 
 109:         case '+':
 110:             which += *cp++;
 111:             /* fall into... */
 112: 
 113:         case '.':
 114: casedot:
 115:             /*
 116: 			 * This code is worth scratching your head at for a
 117: 			 * while.  The idea is that various weird things can
 118: 			 * happen to nulls, EOT's, tabs, and newlines by the
 119: 			 * tty driver, arpanet, and so on, so we don't send
 120: 			 * them if we can help it.
 121: 			 *
 122: 			 * Tab is taken out to get Ann Arbors to work, otherwise
 123: 			 * when they go to column 9 we increment which is wrong
 124: 			 * because bcd isn't continuous.  We should take out
 125: 			 * the rest too, or run the thing through more than
 126: 			 * once until it doesn't make any of these, but that
 127: 			 * would make termlib (and hence pdp-11 ex) bigger,
 128: 			 * and also somewhat slower.  This requires all
 129: 			 * programs which use termlib to stty tabs so they
 130: 			 * don't get expanded.  They should do this anyway
 131: 			 * because some terminals use ^I for other things,
 132: 			 * like nondestructive space.
 133: 			 */
 134:             if (which == 0 || which == CTRL(d) || /* which == '\t' || */ which == '\n') {
 135:                 if (oncol || UP) /* Assumption: backspace works */
 136:                     /*
 137: 					 * Loop needed because newline happens
 138: 					 * to be the successor of tab.
 139: 					 */
 140:                     do {
 141:                         strcat(added, oncol ? (BC ? BC : "\b") : UP);
 142:                         which++;
 143:                     } while (which == '\n');
 144:             }
 145:             *dp++ = which;
 146:             goto swap;
 147: 
 148:         case 'r':
 149:             oncol = 1;
 150:             goto setwhich;
 151: 
 152:         case 'i':
 153:             destcol++;
 154:             destline++;
 155:             which++;
 156:             continue;
 157: 
 158:         case '%':
 159:             *dp++ = c;
 160:             continue;
 161: 
 162: #ifdef CM_B
 163:         case 'B':
 164:             which = (which/10 << 4) + which%10;
 165:             continue;
 166: #endif
 167: 
 168: #ifdef CM_D
 169:         case 'D':
 170:             which = which - 2 * (which%16);
 171:             continue;
 172: #endif
 173: 
 174:         default:
 175:             goto toohard;
 176:         }
 177:     }
 178:     strcpy(dp, added);
 179:     return (result);
 180: }

Defined functions

Defined variables

BC defined in line 16; used 2 times
  • in line 141(2)
UP defined in line 15; used 2 times
sccsid defined in line 8; never used

Defined macros

CTRL defined in line 11; used 1 times
MAXRETURNSIZE defined in line 13; used 1 times
  • in line 47
Last modified: 1989-05-08
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