[unix-history] / usr / src / lib / libtermlib / termcap.c

/* 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];
	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) {
		if (*cp!='/') {
			if (strcmp(name,getenv("TERM"))==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);
}
Commit	Line	Data
3378159f BJ	1	/* Copyright (c) 1979 Regents of the University of California */
	2	#define BUFSIZ 1024
	3	#define MAXHOP 32 /* max number of tc= indirections */
	4
	5	#include <ctype.h>
	6	#include "local/uparm.h"
	7	/*
	8	* termcap - routines for dealing with the terminal capability data base
	9	*
	10	* BUG: Should use a "last" pointer in tbuf, so that searching
	11	* for capabilities alphabetically would not be a n**2/2
	12	* process when large numbers of capabilities are given.
	13	* Note: If we add a last pointer now we will screw up the
	14	* tc capability. We really should compile termcap.
	15	*
	16	* Essentially all the work here is scanning and decoding escapes
	17	* in string capabilities. We don't use stdio because the editor
	18	* doesn't, and because living w/o it is not hard.
	19	*/
	20
	21	static char *tbuf;
	22	static int hopcount; /* detect infinite loops in termcap, init 0 */
	23	char *tskip();
	24	char *tgetstr();
	25	char *tdecode();
	26	char *getenv();
	27
	28	/*
	29	* Get an entry for terminal name in buffer bp,
	30	* from the termcap file. Parse is very rudimentary;
	31	* we just notice escaped newlines.
	32	*/
	33	tgetent(bp, name)
	34	char bp, name;
	35	{
	36	register char *cp;
	37	register int c;
	38	register int i = 0, cnt = 0;
	39	char ibuf[BUFSIZ];
	40	int tf;
	41
	42	tbuf = bp;
	43	tf = 0;
	44	#ifndef V6
	45	cp = getenv("TERMCAP");
	46	/*
	47	* TERMCAP can have one of two things in it. It can be the
	48	* name of a file to use instead of /etc/termcap. In this
	49	* case it better start with a "/". Or it can be an entry to
	50	* use so we don't have to read the file. In this case it
	51	* has to already have the newlines crunched out.
	52	*/
	53	if (cp) {
	54	if (*cp!='/') {
	55	if (strcmp(name,getenv("TERM"))==0) {
	56	strcpy(bp,cp);
	57	return(tnchktc());
	58	} else {
	59	tf = open(E_TERMCAP, 0);
	60	}
	61	} else
	62	tf = open(cp, 0);
	63	}
	64	if (tf==0)
65	tf = open(E_TERMCAP, 0);
66	#else
67	tf = open(E_TERMCAP, 0);
68	#endif
69	if (tf < 0)
70	return (-1);
71	for (;;) {
72	cp = bp;
73	for (;;) {
74	if (i == cnt) {
75	cnt = read(tf, ibuf, BUFSIZ);
76	if (cnt <= 0) {
77	close(tf);
78	return (0);
79	}
80	i = 0;
81	}
82	c = ibuf[i++];
83	if (c == '\n') {
84	if (cp > bp && cp[-1] == '\\'){
85	cp--;
86	continue;
87	}
88	break;
89	}
90	if (cp >= bp+BUFSIZ) {
91	write(2,"Termcap entry too long\n", 23);
92	break;
93	} else
94	*cp++ = c;
95	}
96	*cp = 0;
97
98	/*
99	* The real work for the match.
100	*/
101	if (tnamatch(name)) {
102	close(tf);
103	return(tnchktc());
104	}
105	}
106	}
107
108	/*
109	* tnchktc: check the last entry, see if it's tc=xxx. If so,
110	* recursively find xxx and append that entry (minus the names)
111	* to take the place of the tc=xxx entry. This allows termcap
112	* entries to say "like an HP2621 but doesn't turn on the labels".
113	* Note that this works because of the left to right scan.
114	*/
115	tnchktc()
116	{
117	register char p, q;
118	char tcname[16]; /* name of similar terminal */
119	char tcbuf[BUFSIZ];
120	char *holdtbuf = tbuf;
121	int l;
122
123	p = tbuf + strlen(tbuf) - 2; /* before the last colon */
124	while (*--p != ':')
125	if (p<tbuf) {
126	write(2, "Bad termcap entry\n", 18);
127	return (0);
128	}
129	p++;
130	/* p now points to beginning of last field */
131	if (p[0] != 't' \|\| p[1] != 'c')
132	return(1);
133	strcpy(tcname,p+3);
134	q = tcname;
135	while (q && *q != ':')
136	q++;
137	*q = 0;
138	if (++hopcount > MAXHOP) {
139	write(2, "Infinite tc= loop\n", 18);
140	return (0);
141	}
142	if (tgetent(tcbuf, tcname) != 1)
143	return(0);
144	for (q=tcbuf; *q != ':'; q++)
145	;
146	l = p - holdtbuf + strlen(q);
147	if (l > BUFSIZ) {
148	write(2, "Termcap entry too long\n", 23);
149	q[BUFSIZ - (p-tbuf)] = 0;
150	}
151	strcpy(p, q+1);
152	tbuf = holdtbuf;
153	return(1);
154	}
155
156	/*
157	* Tnamatch deals with name matching. The first field of the termcap
158	* entry is a sequence of names separated by \|'s, so we compare
159	* against each such name. The normal : terminator after the last
160	* name (before the first field) stops us.
161	*/
162	tnamatch(np)
163	char *np;
164	{
165	register char Np, Bp;
166
167	Bp = tbuf;
168	if (*Bp == '#')
169	return(0);
170	for (;;) {
171	for (Np = np; Np && Bp == *Np; Bp++, Np++)
172	continue;
173	if (Np == 0 && (Bp == '\|' \|\| Bp == ':' \|\| Bp == 0))
174	return (1);
175	while (Bp && Bp != ':' && *Bp != '\|')
176	Bp++;
177	if (Bp == 0 \|\| Bp == ':')
178	return (0);
179	Bp++;
180	}
181	}
182
183	/*
184	* Skip to the next field. Notice that this is very dumb, not
185	* knowing about \: escapes or any such. If necessary, :'s can be put
186	* into the termcap file in octal.
187	*/
188	static char *
189	tskip(bp)
190	register char *bp;
191	{
192
193	while (bp && bp != ':')
194	bp++;
195	if (*bp == ':')
196	bp++;
197	return (bp);
198	}
199
200	/*
201	* Return the (numeric) option id.
202	* Numeric options look like
203	* li#80
204	* i.e. the option string is separated from the numeric value by
205	* a # character. If the option is not found we return -1.
206	* Note that we handle octal numbers beginning with 0.
207	*/
208	tgetnum(id)
209	char *id;
210	{
211	register int i, base;
212	register char *bp = tbuf;
213
214	for (;;) {
215	bp = tskip(bp);
216	if (*bp == 0)
217	return (-1);
218	if (bp++ != id[0] \|\| bp == 0 \|\| *bp++ != id[1])
219	continue;
220	if (*bp == '@')
221	return(-1);
222	if (*bp != '#')
223	continue;
224	bp++;
225	base = 10;
226	if (*bp == '0')
227	base = 8;
228	i = 0;
229	while (isdigit(*bp))
230	i = base, i += bp++ - '0';
231	return (i);
232	}
233	}
234
235	/*
236	* Handle a flag option.
237	* Flag options are given "naked", i.e. followed by a : or the end
238	* of the buffer. Return 1 if we find the option, or 0 if it is
239	* not given.
240	*/
241	tgetflag(id)
242	char *id;
243	{
244	register char *bp = tbuf;
245
246	for (;;) {
247	bp = tskip(bp);
248	if (!*bp)
249	return (0);
250	if (bp++ == id[0] && bp != 0 && *bp++ == id[1]) {
251	if (!bp \|\| bp == ':')
252	return (1);
253	else if (*bp == '@')
254	return(0);
255	}
256	}
257	}
258
259	/*
260	* Get a string valued option.
261	* These are given as
262	* cl=^Z
263	* Much decoding is done on the strings, and the strings are
264	* placed in area, which is a ref parameter which is updated.
265	* No checking on area overflow.
266	*/
267	char *
268	tgetstr(id, area)
269	char id, *area;
270	{
271	register char *bp = tbuf;
272
273	for (;;) {
274	bp = tskip(bp);
275	if (!*bp)
276	return (0);
277	if (bp++ != id[0] \|\| bp == 0 \|\| *bp++ != id[1])
278	continue;
279	if (*bp == '@')
280	return(0);
281	if (*bp != '=')
282	continue;
283	bp++;
284	return (tdecode(bp, area));
285	}
286	}
287
288	/*
289	* Tdecode does the grung work to decode the
290	* string capability escapes.
291	*/
292	static char *
293	tdecode(str, area)
294	register char *str;
295	char **area;
296	{
297	register char *cp;
298	register int c;
299	register char *dp;
300	int i;
301
302	cp = *area;
303	while ((c = *str++) && c != ':') {
304	switch (c) {
305
306	case '^':
307	c = *str++ & 037;
308	break;
309
310	case '\\':
311	dp = "E\033^^\\\\::n\nr\rt\tb\bf\f";
312	c = *str++;
313	nextc:
314	if (*dp++ == c) {
315	c = *dp++;
316	break;
317	}
318	dp++;
319	if (*dp)
320	goto nextc;
321	if (isdigit(c)) {
322	c -= '0', i = 2;
323	do
324	c <<= 3, c \|= *str++ - '0';
325	while (--i && isdigit(*str));
326	}
327	break;
328	}
329	*cp++ = c;
330	}
331	*cp++ = 0;
332	str = *area;
333	*area = cp;
334	return (str);
335	}