#ifndef lint static char *sccsid = "@(#)termcap.c 4.1 ULTRIX 7/2/90"; #endif #define BUFSIZ 1024 #define MAXHOP 32 /* max number of tc= indirections */ #define E_TERMCAP "/etc/termcap" #include /* * termcap - routines for dealing with the terminal capability data base * * BUG: Should use a "last" pointer in tbuf, so that searching * for capabilities alphabetically would not be a n**2/2 * process when large numbers of capabilities are given. * Note: If we add a last pointer now we will screw up the * tc capability. We really should compile termcap. * * Essentially all the work here is scanning and decoding escapes * in string capabilities. We don't use stdio because the editor * doesn't, and because living w/o it is not hard. */ /* * MODIFICATION HISTORY * * 15-Mar-88 Tim Burke * * The previous modification introduced the following bug: If the open of * a specified termcap file failed it would look in /etc/termcap; instead * of just reporting the error. * * 14-Aug-87 Tim Burke * * Tgetent() was incorrectly using 0 as an invalid return value from open(). * As a result, if stdin has been closed the value of your TERMCAP variable * would not be used if it is a file. (Thanks to M. Mendel) */ static char *tbuf; static int hopcount; /* detect infinite loops in termcap, init 0 */ char *tskip(); char *tgetstr(); char *tdecode(); char *getenv(); /* * Get an entry for terminal name in buffer bp, * from the termcap file. Parse is very rudimentary; * we just notice escaped newlines. */ tgetent(bp, name) char *bp, *name; { register char *cp; register int c; register int i = 0, cnt = 0; char ibuf[BUFSIZ]; char *cp2; int tf; tbuf = bp; tf = -1; #ifndef V6 cp = getenv("TERMCAP"); /* * TERMCAP can have one of two things in it. It can be the * name of a file to use instead of /etc/termcap. In this * case it better start with a "/". Or it can be an entry to * use so we don't have to read the file. In this case it * has to already have the newlines crunched out. */ if (cp && *cp) { if (*cp!='/') { cp2 = getenv("TERM"); if (cp2==(char *) 0 || strcmp(name,cp2)==0) { strcpy(bp,cp); return(tnchktc()); } else { tf = open(E_TERMCAP, 0); } } else { tf = open(cp, 0); if (tf < 0) return (-1); } } if (tf==-1) tf = open(E_TERMCAP, 0); #else tf = open(E_TERMCAP, 0); #endif if (tf < 0) return (-1); for (;;) { cp = bp; for (;;) { if (i == cnt) { cnt = read(tf, ibuf, BUFSIZ); if (cnt close(tf); return (0); } i = 0; } c = ibuf[i++]; if (c == '\n') { if (cp > bp && cp[-1] == '\\'){ cp--; continue; } break; } if (cp >= bp+BUFSIZ) { write(2,"Termcap entry too long\n", 23); break; } else *cp++ = c; } *cp = 0; /* * The real work for the match. */ if (tnamatch(name)) { close(tf); return(tnchktc()); } } } /* * tnchktc: check the last entry, see if it's tc=xxx. If so, * recursively find xxx and append that entry (minus the names) * to take the place of the tc=xxx entry. This allows termcap * entries to say "like an HP2621 but doesn't turn on the labels". * Note that this works because of the left to right scan. */ tnchktc() { register char *p, *q; char tcname[16]; /* name of similar terminal */ char tcbuf[BUFSIZ]; char *holdtbuf = tbuf; int l; p = tbuf + strlen(tbuf) - 2; /* before the last colon */ while (*--p != ':') if (p write(2, "Bad termcap entry\n", 18); return (0); } p++; /* p now points to beginning of last field */ if (p[0] != 't' || p[1] != 'c') return(1); strcpy(tcname,p+3); q = tcname; while (q && *q != ':') q++; *q = 0; if (++hopcount > MAXHOP) { write(2, "Infinite tc= loop\n", 18); return (0); } if (tgetent(tcbuf, tcname) != 1) return(0); for (q=tcbuf; *q != ':'; q++) ; l = p - holdtbuf + strlen(q); if (l > BUFSIZ) { write(2, "Termcap entry too long\n", 23); q[BUFSIZ - (p-tbuf)] = 0; } strcpy(p, q+1); tbuf = holdtbuf; return(1); } /* * Tnamatch deals with name matching. The first field of the termcap * entry is a sequence of names separated by |'s, so we compare * against each such name. The normal : terminator after the last * name (before the first field) stops us. */ tnamatch(np) char *np; { register char *Np, *Bp; Bp = tbuf; if (*Bp == '#') return(0); for (;;) { for (Np = np; *Np && *Bp == *Np; Bp++, Np++) continue; if (*Np == 0 && (*Bp == '|' || *Bp == ':' || *Bp == 0)) return (1); while (*Bp && *Bp != ':' && *Bp != '|') Bp++; if (*Bp == 0 || *Bp == ':') return (0); Bp++; } } /* * Skip to the next field. Notice that this is very dumb, not * knowing about \: escapes or any such. If necessary, :'s can be put * into the termcap file in octal. */ static char * tskip(bp) register char *bp; { while (*bp && *bp != ':') bp++; if (*bp == ':') bp++; return (bp); } /* * Return the (numeric) option id. * Numeric options look like * li#80 * i.e. the option string is separated from the numeric value by * a # character. If the option is not found we return -1. * Note that we handle octal numbers beginning with 0. */ tgetnum(id) char *id; { register int i, base; register char *bp = tbuf; for (;;) { bp = tskip(bp); if (*bp == 0) return (-1); if (*bp++ != id[0] || *bp == 0 || *bp++ != id[1]) continue; if (*bp == '@') return(-1); if (*bp != '#') continue; bp++; base = 10; if (*bp == '0') base = 8; i = 0; while (isdigit(*bp)) i *= base, i += *bp++ - '0'; return (i); } } /* * Handle a flag option. * Flag options are given "naked", i.e. followed by a : or the end * of the buffer. Return 1 if we find the option, or 0 if it is * not given. */ tgetflag(id) char *id; { register char *bp = tbuf; for (;;) { bp = tskip(bp); if (!*bp) return (0); if (*bp++ == id[0] && *bp != 0 && *bp++ == id[1]) { if (!*bp || *bp == ':') return (1); else if (*bp == '@') return(0); } } } /* * Get a string valued option. * These are given as * cl=^Z * Much decoding is done on the strings, and the strings are * placed in area, which is a ref parameter which is updated. * No checking on area overflow. */ char * tgetstr(id, area) char *id, **area; { register char *bp = tbuf; for (;;) { bp = tskip(bp); if (!*bp) return (0); if (*bp++ != id[0] || *bp == 0 || *bp++ != id[1]) continue; if (*bp == '@') return(0); if (*bp != '=') continue; bp++; return (tdecode(bp, area)); } } /* * Tdecode does the grung work to decode the * string capability escapes. */ static char * tdecode(str, area) register char *str; char **area; { register char *cp; register int c; register char *dp; int i; cp = *area; while ((c = *str++) && c != ':') { switch (c) { case '^': c = *str++ & 037; break; case '\\': dp = "E\033^^\\\\::n\nr\rt\tb\bf\f"; c = *str++; nextc: if (*dp++ == c) { c = *dp++; break; } dp++; if (*dp) goto nextc; if (isdigit(c)) { c -= '0', i = 2; do c while (--i && isdigit(*str)); } break; } *cp++ = c; } *cp++ = 0; str = *area; *area = cp; return (str); }
