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[] = "@(#)termcap.c	5.1 (Berkeley) 6/5/85";
   9: #endif not lint
  10: 
  11: #define BUFSIZ      1024
  12: #define MAXHOP      32  /* max number of tc= indirections */
  13: #define E_TERMCAP   "/etc/termcap"
  14: 
  15: #include <ctype.h>
  16: /*
  17:  * termcap - routines for dealing with the terminal capability data base
  18:  *
  19:  * BUG:		Should use a "last" pointer in tbuf, so that searching
  20:  *		for capabilities alphabetically would not be a n**2/2
  21:  *		process when large numbers of capabilities are given.
  22:  * Note:	If we add a last pointer now we will screw up the
  23:  *		tc capability. We really should compile termcap.
  24:  *
  25:  * Essentially all the work here is scanning and decoding escapes
  26:  * in string capabilities.  We don't use stdio because the editor
  27:  * doesn't, and because living w/o it is not hard.
  28:  */
  29: 
  30: static  char *tbuf;
  31: static  int hopcount;   /* detect infinite loops in termcap, init 0 */
  32: char    *tskip();
  33: char    *tgetstr();
  34: char    *tdecode();
  35: char    *getenv();
  36: 
  37: /*
  38:  * Get an entry for terminal name in buffer bp,
  39:  * from the termcap file.  Parse is very rudimentary;
  40:  * we just notice escaped newlines.
  41:  */
  42: tgetent(bp, name)
  43:     char *bp, *name;
  44: {
  45:     register char *cp;
  46:     register int c;
  47:     register int i = 0, cnt = 0;
  48:     char ibuf[BUFSIZ];
  49:     int tf;
  50: 
  51:     tbuf = bp;
  52:     tf = -1;
  53: #ifndef V6
  54:     cp = getenv("TERMCAP");
  55:     /*
  56: 	 * TERMCAP can have one of two things in it. It can be the
  57: 	 * name of a file to use instead of /etc/termcap. In this
  58: 	 * case it better start with a "/". Or it can be an entry to
  59: 	 * use so we don't have to read the file. In this case it
  60: 	 * has to already have the newlines crunched out.
  61: 	 */
  62:     if (cp && *cp) {
  63:         if (*cp == '/') {
  64:             tf = open(cp, 0);
  65:         } else {
  66:             tbuf = cp;
  67:             c = tnamatch(name);
  68:             tbuf = bp;
  69:             if (c) {
  70:                 strcpy(bp,cp);
  71:                 return(tnchktc());
  72:             }
  73:         }
  74:     }
  75:     if (tf < 0)
  76:         tf = open(E_TERMCAP, 0);
  77: #else
  78:     tf = open(E_TERMCAP, 0);
  79: #endif
  80:     if (tf < 0)
  81:         return (-1);
  82:     for (;;) {
  83:         cp = bp;
  84:         for (;;) {
  85:             if (i == cnt) {
  86:                 cnt = read(tf, ibuf, BUFSIZ);
  87:                 if (cnt <= 0) {
  88:                     close(tf);
  89:                     return (0);
  90:                 }
  91:                 i = 0;
  92:             }
  93:             c = ibuf[i++];
  94:             if (c == '\n') {
  95:                 if (cp > bp && cp[-1] == '\\'){
  96:                     cp--;
  97:                     continue;
  98:                 }
  99:                 break;
 100:             }
 101:             if (cp >= bp+BUFSIZ) {
 102:                 write(2,"Termcap entry too long\n", 23);
 103:                 break;
 104:             } else
 105:                 *cp++ = c;
 106:         }
 107:         *cp = 0;
 108: 
 109:         /*
 110: 		 * The real work for the match.
 111: 		 */
 112:         if (tnamatch(name)) {
 113:             close(tf);
 114:             return(tnchktc());
 115:         }
 116:     }
 117: }
 118: 
 119: /*
 120:  * tnchktc: check the last entry, see if it's tc=xxx. If so,
 121:  * recursively find xxx and append that entry (minus the names)
 122:  * to take the place of the tc=xxx entry. This allows termcap
 123:  * entries to say "like an HP2621 but doesn't turn on the labels".
 124:  * Note that this works because of the left to right scan.
 125:  */
 126: tnchktc()
 127: {
 128:     register char *p, *q;
 129:     char tcname[16];    /* name of similar terminal */
 130:     char tcbuf[BUFSIZ];
 131:     char *holdtbuf = tbuf;
 132:     int l;
 133: 
 134:     p = tbuf + strlen(tbuf) - 2;    /* before the last colon */
 135:     while (*--p != ':')
 136:         if (p<tbuf) {
 137:             write(2, "Bad termcap entry\n", 18);
 138:             return (0);
 139:         }
 140:     p++;
 141:     /* p now points to beginning of last field */
 142:     if (p[0] != 't' || p[1] != 'c')
 143:         return(1);
 144:     strcpy(tcname,p+3);
 145:     q = tcname;
 146:     while (*q && *q != ':')
 147:         q++;
 148:     *q = 0;
 149:     if (++hopcount > MAXHOP) {
 150:         write(2, "Infinite tc= loop\n", 18);
 151:         return (0);
 152:     }
 153:     if (tgetent(tcbuf, tcname) != 1) {
 154:         hopcount = 0;       /* unwind recursion */
 155:         return(0);
 156:     }
 157:     for (q=tcbuf; *q != ':'; q++)
 158:         ;
 159:     l = p - holdtbuf + strlen(q);
 160:     if (l > BUFSIZ) {
 161:         write(2, "Termcap entry too long\n", 23);
 162:         q[BUFSIZ - (p-tbuf)] = 0;
 163:     }
 164:     strcpy(p, q+1);
 165:     tbuf = holdtbuf;
 166:     hopcount = 0;           /* unwind recursion */
 167:     return(1);
 168: }
 169: 
 170: /*
 171:  * Tnamatch deals with name matching.  The first field of the termcap
 172:  * entry is a sequence of names separated by |'s, so we compare
 173:  * against each such name.  The normal : terminator after the last
 174:  * name (before the first field) stops us.
 175:  */
 176: tnamatch(np)
 177:     char *np;
 178: {
 179:     register char *Np, *Bp;
 180: 
 181:     Bp = tbuf;
 182:     if (*Bp == '#')
 183:         return(0);
 184:     for (;;) {
 185:         for (Np = np; *Np && *Bp == *Np; Bp++, Np++)
 186:             continue;
 187:         if (*Np == 0 && (*Bp == '|' || *Bp == ':' || *Bp == 0))
 188:             return (1);
 189:         while (*Bp && *Bp != ':' && *Bp != '|')
 190:             Bp++;
 191:         if (*Bp == 0 || *Bp == ':')
 192:             return (0);
 193:         Bp++;
 194:     }
 195: }
 196: 
 197: /*
 198:  * Skip to the next field.  Notice that this is very dumb, not
 199:  * knowing about \: escapes or any such.  If necessary, :'s can be put
 200:  * into the termcap file in octal.
 201:  */
 202: static char *
 203: tskip(bp)
 204:     register char *bp;
 205: {
 206: 
 207:     while (*bp && *bp != ':')
 208:         bp++;
 209:     if (*bp == ':')
 210:         bp++;
 211:     return (bp);
 212: }
 213: 
 214: /*
 215:  * Return the (numeric) option id.
 216:  * Numeric options look like
 217:  *	li#80
 218:  * i.e. the option string is separated from the numeric value by
 219:  * a # character.  If the option is not found we return -1.
 220:  * Note that we handle octal numbers beginning with 0.
 221:  */
 222: tgetnum(id)
 223:     char *id;
 224: {
 225:     register int i, base;
 226:     register char *bp = tbuf;
 227: 
 228:     for (;;) {
 229:         bp = tskip(bp);
 230:         if (*bp == 0)
 231:             return (-1);
 232:         if (*bp++ != id[0] || *bp == 0 || *bp++ != id[1])
 233:             continue;
 234:         if (*bp == '@')
 235:             return(-1);
 236:         if (*bp != '#')
 237:             continue;
 238:         bp++;
 239:         base = 10;
 240:         if (*bp == '0')
 241:             base = 8;
 242:         i = 0;
 243:         while (isdigit(*bp))
 244:             i *= base, i += *bp++ - '0';
 245:         return (i);
 246:     }
 247: }
 248: 
 249: /*
 250:  * Handle a flag option.
 251:  * Flag options are given "naked", i.e. followed by a : or the end
 252:  * of the buffer.  Return 1 if we find the option, or 0 if it is
 253:  * not given.
 254:  */
 255: tgetflag(id)
 256:     char *id;
 257: {
 258:     register char *bp = tbuf;
 259: 
 260:     for (;;) {
 261:         bp = tskip(bp);
 262:         if (!*bp)
 263:             return (0);
 264:         if (*bp++ == id[0] && *bp != 0 && *bp++ == id[1]) {
 265:             if (!*bp || *bp == ':')
 266:                 return (1);
 267:             else if (*bp == '@')
 268:                 return(0);
 269:         }
 270:     }
 271: }
 272: 
 273: /*
 274:  * Get a string valued option.
 275:  * These are given as
 276:  *	cl=^Z
 277:  * Much decoding is done on the strings, and the strings are
 278:  * placed in area, which is a ref parameter which is updated.
 279:  * No checking on area overflow.
 280:  */
 281: char *
 282: tgetstr(id, area)
 283:     char *id, **area;
 284: {
 285:     register char *bp = tbuf;
 286: 
 287:     for (;;) {
 288:         bp = tskip(bp);
 289:         if (!*bp)
 290:             return (0);
 291:         if (*bp++ != id[0] || *bp == 0 || *bp++ != id[1])
 292:             continue;
 293:         if (*bp == '@')
 294:             return(0);
 295:         if (*bp != '=')
 296:             continue;
 297:         bp++;
 298:         return (tdecode(bp, area));
 299:     }
 300: }
 301: 
 302: /*
 303:  * Tdecode does the grung work to decode the
 304:  * string capability escapes.
 305:  */
 306: static char *
 307: tdecode(str, area)
 308:     register char *str;
 309:     char **area;
 310: {
 311:     register char *cp;
 312:     register int c;
 313:     register char *dp;
 314:     int i;
 315: 
 316:     cp = *area;
 317:     while ((c = *str++) && c != ':') {
 318:         switch (c) {
 319: 
 320:         case '^':
 321:             c = *str++ & 037;
 322:             break;
 323: 
 324:         case '\\':
 325:             dp = "E\033^^\\\\::n\nr\rt\tb\bf\f";
 326:             c = *str++;
 327: nextc:
 328:             if (*dp++ == c) {
 329:                 c = *dp++;
 330:                 break;
 331:             }
 332:             dp++;
 333:             if (*dp)
 334:                 goto nextc;
 335:             if (isdigit(c)) {
 336:                 c -= '0', i = 2;
 337:                 do
 338:                     c <<= 3, c |= *str++ - '0';
 339:                 while (--i && isdigit(*str));
 340:             }
 341:             break;
 342:         }
 343:         *cp++ = c;
 344:     }
 345:     *cp++ = 0;
 346:     str = *area;
 347:     *area = cp;
 348:     return (str);
 349: }

Defined functions

tdecode defined in line 306; used 2 times
tgetstr defined in line 281; used 195 times
tnamatch defined in line 176; used 2 times
tnchktc defined in line 126; used 2 times
tskip defined in line 202; used 4 times

Defined variables

hopcount defined in line 31; used 3 times
sccsid defined in line 8; never used
tbuf defined in line 30; used 13 times

Defined macros

BUFSIZ defined in line 11; used 6 times
E_TERMCAP defined in line 13; used 2 times
MAXHOP defined in line 12; used 1 times
Last modified: 1989-05-08
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