Ultrix-3.1/src/libtermlib/termcap.c
/**********************************************************************
* Copyright (c) Digital Equipment Corporation 1984, 1985, 1986. *
* All Rights Reserved. *
* Reference "/usr/src/COPYRIGHT" for applicable restrictions. *
**********************************************************************/
/* SCCSID: @(#)termcap.c 3.0 4/22/86 */
/* Copyright (c) 1979 Regents of the University of California */
#define BUFSIZ 1024
#define MAXHOP 32 /* max number of tc= indirections */
#include <ctype.h>
#include "local/uparm.h"
/*
* 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.
*/
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 = 0;
#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)
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 <= 0) {
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<tbuf) {
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 <<= 3, c |= *str++ - '0';
while (--i && isdigit(*str));
}
break;
}
*cp++ = c;
}
*cp++ = 0;
str = *area;
*area = cp;
return (str);
}