| 1 | /* |
| 2 | * Copyright (c) 1980 The Regents of the University of California. |
| 3 | * All rights reserved. |
| 4 | * |
| 5 | * %sccs.include.redist.c% |
| 6 | */ |
| 7 | |
| 8 | #ifndef lint |
| 9 | static char sccsid[] = "@(#)tgoto.c 5.4 (Berkeley) %G%"; |
| 10 | #endif /* not lint */ |
| 11 | |
| 12 | #define CTRL(c) ((c) & 037) |
| 13 | |
| 14 | #define MAXRETURNSIZE 64 |
| 15 | |
| 16 | char *UP; |
| 17 | char *BC; |
| 18 | |
| 19 | /* |
| 20 | * Routine to perform cursor addressing. |
| 21 | * CM is a string containing printf type escapes to allow |
| 22 | * cursor addressing. We start out ready to print the destination |
| 23 | * line, and switch each time we print row or column. |
| 24 | * The following escapes are defined for substituting row/column: |
| 25 | * |
| 26 | * %d as in printf |
| 27 | * %2 like %2d |
| 28 | * %3 like %3d |
| 29 | * %. gives %c hacking special case characters |
| 30 | * %+x like %c but adding x first |
| 31 | * |
| 32 | * The codes below affect the state but don't use up a value. |
| 33 | * |
| 34 | * %>xy if value > x add y |
| 35 | * %r reverses row/column |
| 36 | * %i increments row/column (for one origin indexing) |
| 37 | * %% gives % |
| 38 | * %B BCD (2 decimal digits encoded in one byte) |
| 39 | * %D Delta Data (backwards bcd) |
| 40 | * |
| 41 | * all other characters are ``self-inserting''. |
| 42 | */ |
| 43 | char * |
| 44 | tgoto(CM, destcol, destline) |
| 45 | char *CM; |
| 46 | int destcol, destline; |
| 47 | { |
| 48 | static char result[MAXRETURNSIZE]; |
| 49 | static char added[10]; |
| 50 | char *cp = CM; |
| 51 | register char *dp = result; |
| 52 | register int c; |
| 53 | int oncol = 0; |
| 54 | register int which = destline; |
| 55 | |
| 56 | if (cp == 0) { |
| 57 | toohard: |
| 58 | /* |
| 59 | * ``We don't do that under BOZO's big top'' |
| 60 | */ |
| 61 | return ("OOPS"); |
| 62 | } |
| 63 | added[0] = 0; |
| 64 | while (c = *cp++) { |
| 65 | if (c != '%') { |
| 66 | *dp++ = c; |
| 67 | continue; |
| 68 | } |
| 69 | switch (c = *cp++) { |
| 70 | |
| 71 | #ifdef CM_N |
| 72 | case 'n': |
| 73 | destcol ^= 0140; |
| 74 | destline ^= 0140; |
| 75 | goto setwhich; |
| 76 | #endif |
| 77 | |
| 78 | case 'd': |
| 79 | if (which < 10) |
| 80 | goto one; |
| 81 | if (which < 100) |
| 82 | goto two; |
| 83 | /* fall into... */ |
| 84 | |
| 85 | case '3': |
| 86 | *dp++ = (which / 100) | '0'; |
| 87 | which %= 100; |
| 88 | /* fall into... */ |
| 89 | |
| 90 | case '2': |
| 91 | two: |
| 92 | *dp++ = which / 10 | '0'; |
| 93 | one: |
| 94 | *dp++ = which % 10 | '0'; |
| 95 | swap: |
| 96 | oncol = 1 - oncol; |
| 97 | setwhich: |
| 98 | which = oncol ? destcol : destline; |
| 99 | continue; |
| 100 | |
| 101 | #ifdef CM_GT |
| 102 | case '>': |
| 103 | if (which > *cp++) |
| 104 | which += *cp++; |
| 105 | else |
| 106 | cp++; |
| 107 | continue; |
| 108 | #endif |
| 109 | |
| 110 | case '+': |
| 111 | which += *cp++; |
| 112 | /* fall into... */ |
| 113 | |
| 114 | case '.': |
| 115 | casedot: |
| 116 | /* |
| 117 | * This code is worth scratching your head at for a |
| 118 | * while. The idea is that various weird things can |
| 119 | * happen to nulls, EOT's, tabs, and newlines by the |
| 120 | * tty driver, arpanet, and so on, so we don't send |
| 121 | * them if we can help it. |
| 122 | * |
| 123 | * Tab is taken out to get Ann Arbors to work, otherwise |
| 124 | * when they go to column 9 we increment which is wrong |
| 125 | * because bcd isn't continuous. We should take out |
| 126 | * the rest too, or run the thing through more than |
| 127 | * once until it doesn't make any of these, but that |
| 128 | * would make termlib (and hence pdp-11 ex) bigger, |
| 129 | * and also somewhat slower. This requires all |
| 130 | * programs which use termlib to stty tabs so they |
| 131 | * don't get expanded. They should do this anyway |
| 132 | * because some terminals use ^I for other things, |
| 133 | * like nondestructive space. |
| 134 | */ |
| 135 | if (which == 0 || which == CTRL('d') || /* which == '\t' || */ which == '\n') { |
| 136 | if (oncol || UP) /* Assumption: backspace works */ |
| 137 | /* |
| 138 | * Loop needed because newline happens |
| 139 | * to be the successor of tab. |
| 140 | */ |
| 141 | do { |
| 142 | strcat(added, oncol ? (BC ? BC : "\b") : UP); |
| 143 | which++; |
| 144 | } while (which == '\n'); |
| 145 | } |
| 146 | *dp++ = which; |
| 147 | goto swap; |
| 148 | |
| 149 | case 'r': |
| 150 | oncol = 1; |
| 151 | goto setwhich; |
| 152 | |
| 153 | case 'i': |
| 154 | destcol++; |
| 155 | destline++; |
| 156 | which++; |
| 157 | continue; |
| 158 | |
| 159 | case '%': |
| 160 | *dp++ = c; |
| 161 | continue; |
| 162 | |
| 163 | #ifdef CM_B |
| 164 | case 'B': |
| 165 | which = (which/10 << 4) + which%10; |
| 166 | continue; |
| 167 | #endif |
| 168 | |
| 169 | #ifdef CM_D |
| 170 | case 'D': |
| 171 | which = which - 2 * (which%16); |
| 172 | continue; |
| 173 | #endif |
| 174 | |
| 175 | default: |
| 176 | goto toohard; |
| 177 | } |
| 178 | } |
| 179 | strcpy(dp, added); |
| 180 | return (result); |
| 181 | } |