[unix-history] / usr / othersrc / public / less-177 / prompt.c

/*
 * Prompting and other messages.
 * There are three flavors of prompts, SHORT, MEDIUM and LONG,
 * selected by the -m/-M options.
 * There is also the "equals message", printed by the = command.
 * A prompt is a message composed of various pieces, such as the 
 * name of the file being viewed, the percentage into the file, etc.
 */

#include "less.h"
#include "position.h"

extern int pr_type;
extern int hit_eof;
extern int new_file;
extern int sc_width;
extern int so_s_width, so_e_width;
extern int linenums;
extern int sc_height;
extern int jump_sline;
extern IFILE curr_ifile;
#if EDITOR
extern char *editor;
#endif

/*
 * Prototypes for the three flavors of prompts.
 * These strings are expanded by pr_expand().
 */
static char s_proto[] =
  "?n?f%f .?m(file %i of %m) ..?e(END) ?x- Next\\: %x..%t";
static char m_proto[] =
  "?n?f%f .?m(file %i of %m) ..?e(END) ?x- Next\\: %x.:?pB%pB\\%:byte %bB?s/%s...%t";
static char M_proto[] =
  "?f%f .?n?m(file %i of %m) ..?ltline %lt?L/%L. :byte %bB?s/%s. .?e(END) ?x- Next\\: %x.:?pB%pB\\%..%t";
static char e_proto[] =
  "?f%f .?m(file %i of %m) .?ltline %lt?L/%L. .byte %bB?s/%s. ?e(END) :?pB%pB\\%..%t";

public char *prproto[3];
public char *eqproto = e_proto;

static char message[250];
static char *mp;

/*
 * Initialize the prompt prototype strings.
 */
	public void
init_prompt()
{
	prproto[0] = save(s_proto);
	prproto[1] = save(m_proto);
	prproto[2] = save(M_proto);
	eqproto = save(e_proto);
}

/*
 * Set the message pointer to the end of the message string.
 */
	static void
setmp()
{
	while (*mp != '\0')
		mp++;
}

/*
 * Append a POSITION (as a decimal integer) to the end of the message.
 */
	static void
ap_pos(pos)
	POSITION pos;
{
	sprintf(mp, "%ld", (long)pos);
	setmp();
}

/*
 * Append an integer to the end of the message.
 */
	static void
ap_int(n)
	int n;
{
	sprintf(mp, "%d", n);
	setmp();
}

/*
 * Append a string to the end of the message.
 */
	static void
ap_str(s)
	char *s;
{
	strtcpy(mp, s, (unsigned int)(&message[sizeof(message)] - mp));
	setmp();
}

/*
 * Append a question mark to the end of the message.
 */
	static void
ap_quest()
{
	*mp++ = '?';
}

/*
 * Return the "current" byte offset in the file.
 */
	static POSITION
curr_byte(where)
	int where;
{
	POSITION pos;

	pos = position(where);
	while (pos == NULL_POSITION && where >= 0 && where < sc_height)
		pos = position(++where);
	if (pos == NULL_POSITION)
		pos = ch_length();
	return (pos);
}

/*
 * Return the value of a prototype conditional.
 * A prototype string may include conditionals which consist of a 
 * question mark followed by a single letter.
 * Here we decode that letter and return the appropriate boolean value.
 */
	static int
cond(c, where)
	char c;
	int where;
{
	switch (c)
	{
	case 'a':	/* Anything in the message yet? */
		return (mp > message);
	case 'b':	/* Current byte offset known? */
		return (curr_byte(where) != NULL_POSITION);
	case 'e':	/* At end of file? */
		return (hit_eof);
	case 'f':	/* Filename known? */
		return (strcmp(get_filename(curr_ifile), "-") != 0);
	case 'l':	/* Line number known? */
		return (linenums);
	case 'L':	/* Final line number known? */
		return (linenums && ch_length() != NULL_POSITION);
	case 'm':	/* More than one file? */
		return (nifile() > 1);
	case 'n':	/* First prompt in a new file? */
		return (new_file);
	case 'p':	/* Percent into file known? */
		return (curr_byte(where) != NULL_POSITION && 
				ch_length() > 0);
	case 's':	/* Size of file known? */
	case 'B':
		return (ch_length() != NULL_POSITION);
	case 'x':	/* Is there a "next" file? */
		return (next_ifile(curr_ifile) != NULL_IFILE);
	}
	return (0);
}

/*
 * Decode a "percent" prototype character.
 * A prototype string may include various "percent" escapes;
 * that is, a percent sign followed by a single letter.
 * Here we decode that letter and take the appropriate action,
 * usually by appending something to the message being built.
 */
	static void
protochar(c, where)
	int c;
	int where;
{
	POSITION pos;
	POSITION len;
	int n;
	IFILE h;

	switch (c)
	{
	case 'b':	/* Current byte offset */
		pos = curr_byte(where);
		if (pos != NULL_POSITION)
			ap_pos(pos);
		else
			ap_quest();
		break;
#if EDITOR
	case 'E':	/* Editor name */
		ap_str(editor);
		break;
#endif
	case 'f':	/* File name */
		ap_str(get_filename(curr_ifile));
		break;
	case 'i':	/* Index into list of files */
		ap_int(get_index(curr_ifile));
		break;
	case 'l':	/* Current line number */
		n = currline(where);
		if (n != 0)
			ap_int(n);
		else
			ap_quest();
		break;
	case 'L':	/* Final line number */
		len = ch_length();
		if (len == NULL_POSITION || len == ch_zero() ||
		    (n = find_linenum(len)) <= 0)
			ap_quest();
		else
			ap_int(n-1);
		break;
	case 'm':	/* Number of files */
		ap_int(nifile());
		break;
	case 'p':	/* Percent into file */
		pos = curr_byte(where);
		len = ch_length();
		if (pos != NULL_POSITION && len > 0)
			/*
			 * {{ This calculation may overflow! }}
			 */
			ap_int((int)(100*pos / len));
		else
			ap_quest();
		break;
	case 's':	/* Size of file */
	case 'B':
		len = ch_length();
		if (len != NULL_POSITION)
			ap_pos(len);
		else
			ap_quest();
		break;
	case 't':	/* Truncate trailing spaces in the message */
		while (mp > message && mp[-1] == ' ')
			mp--;
		break;
	case 'x':	/* Name of next file */
		h = next_ifile(curr_ifile);
		if (h != NULL_IFILE)
			ap_str(get_filename(h));
		else
			ap_quest();
		break;
	}
}

/*
 * Skip a false conditional.
 * When a false condition is found (either a false IF or the ELSE part 
 * of a true IF), this routine scans the prototype string to decide
 * where to resume parsing the string.
 * We must keep track of nested IFs and skip them properly.
 */
	static char *
skipcond(p)
	register char *p;
{
	register int iflevel;

	/*
	 * We came in here after processing a ? or :,
	 * so we start nested one level deep.
	 */
	iflevel = 1;

	for (;;) switch (*++p)
	{
	case '?':
		/*
		 * Start of a nested IF.
		 */
		iflevel++;
		break;
	case ':':
		/*
		 * Else.
		 * If this matches the IF we came in here with,
		 * then we're done.
		 */
		if (iflevel == 1)
			return (p);
		break;
	case '.':
		/*
		 * Endif.
		 * If this matches the IF we came in here with,
		 * then we're done.
		 */
		if (--iflevel == 0)
			return (p);
		break;
	case '\\':
		/*
		 * Backslash escapes the next character.
		 */
		++p;
		break;
	case '\0':
		/*
		 * Whoops.  Hit end of string.
		 * This is a malformed conditional, but just treat it
		 * as if all active conditionals ends here.
		 */
		return (p-1);
	}
	/*NOTREACHED*/
}

	static char *
wherechar(p, wp)
	char *p;
	int *wp;
{
	switch (*p)
	{
	case 'b': case 'l': case 'p':
		switch (*++p)
		{
		case 't':   *wp = TOP;			break;
		case 'm':   *wp = MIDDLE;		break;
		case 'b':   *wp = BOTTOM;		break;
		case 'B':   *wp = BOTTOM_PLUS_ONE;	break;
		case 'j':   *wp = adjsline(jump_sline);	break;
		default:    *wp = TOP;  p--;		break;
		}
	}
	return (p);
}

/*
 * Construct a message based on a prototype string.
 */
	public char *
pr_expand(proto, maxwidth)
	char *proto;
	int maxwidth;
{
	register char *p;
	register int c;
	int where;

	mp = message;

	if (*proto == '\0')
		return ("");

	for (p = proto;  *p != '\0';  p++)
	{
		switch (*p)
		{
		default:	/* Just put the character in the message */
			*mp++ = *p;
			break;
		case '\\':	/* Backslash escapes the next character */
			p++;
			*mp++ = *p;
			break;
		case '?':	/* Conditional (IF) */
			if ((c = *++p) == '\0')
				--p;
			else
			{
				p = wherechar(p, &where);
				if (!cond(c, where))
					p = skipcond(p);
			}
			break;
		case ':':	/* ELSE */
			p = skipcond(p);
			break;
		case '.':	/* ENDIF */
			break;
		case '%':	/* Percent escape */
			if ((c = *++p) == '\0')
				--p;
			else
			{
				p = wherechar(p, &where);
				protochar(c, where);
			}
			break;
		}
	}

	new_file = 0;
	if (mp == message)
		return (NULL);
	*mp = '\0';
	if (maxwidth > 0 && mp >= message + maxwidth)
	{
		/*
		 * Message is too long.
		 * Return just the final portion of it.
		 */
		return (mp - maxwidth);
	}
	return (message);
}

/*
 * Return a message suitable for printing by the "=" command.
 */
	public char *
eq_message()
{
	return (pr_expand(eqproto, 0));
}

/*
 * Return a prompt.
 * This depends on the prompt type (SHORT, MEDIUM, LONG), etc.
 * If we can't come up with an appropriate prompt, return NULL
 * and the caller will prompt with a colon.
 */
	public char *
pr_string()
{
	return (pr_expand(prproto[pr_type], sc_width-so_s_width-so_e_width-2));
}
Commit	Line	Data
77e25d77 WJ	1	/*
	2	* Prompting and other messages.
	3	* There are three flavors of prompts, SHORT, MEDIUM and LONG,
	4	* selected by the -m/-M options.
	5	* There is also the "equals message", printed by the = command.
	6	* A prompt is a message composed of various pieces, such as the
	7	* name of the file being viewed, the percentage into the file, etc.
	8	*/
	9
	10	#include "less.h"
	11	#include "position.h"
	12
	13	extern int pr_type;
	14	extern int hit_eof;
	15	extern int new_file;
	16	extern int sc_width;
	17	extern int so_s_width, so_e_width;
	18	extern int linenums;
	19	extern int sc_height;
	20	extern int jump_sline;
	21	extern IFILE curr_ifile;
	22	#if EDITOR
	23	extern char *editor;
	24	#endif
	25
	26	/*
	27	* Prototypes for the three flavors of prompts.
	28	* These strings are expanded by pr_expand().
	29	*/
	30	static char s_proto[] =
	31	"?n?f%f .?m(file %i of %m) ..?e(END) ?x- Next\\: %x..%t";
	32	static char m_proto[] =
	33	"?n?f%f .?m(file %i of %m) ..?e(END) ?x- Next\\: %x.:?pB%pB\\%:byte %bB?s/%s...%t";
	34	static char M_proto[] =
	35	"?f%f .?n?m(file %i of %m) ..?ltline %lt?L/%L. :byte %bB?s/%s. .?e(END) ?x- Next\\: %x.:?pB%pB\\%..%t";
	36	static char e_proto[] =
	37	"?f%f .?m(file %i of %m) .?ltline %lt?L/%L. .byte %bB?s/%s. ?e(END) :?pB%pB\\%..%t";
	38
	39	public char *prproto[3];
	40	public char *eqproto = e_proto;
	41
	42	static char message[250];
	43	static char *mp;
	44
	45	/*
	46	* Initialize the prompt prototype strings.
	47	*/
	48	public void
	49	init_prompt()
	50	{
	51	prproto[0] = save(s_proto);
	52	prproto[1] = save(m_proto);
	53	prproto[2] = save(M_proto);
	54	eqproto = save(e_proto);
	55	}
	56
	57	/*
	58	* Set the message pointer to the end of the message string.
	59	*/
	60	static void
	61	setmp()
	62	{
	63	while (*mp != '\0')
	64	mp++;
65	}
66
67	/*
68	* Append a POSITION (as a decimal integer) to the end of the message.
69	*/
70	static void
71	ap_pos(pos)
72	POSITION pos;
73	{
74	sprintf(mp, "%ld", (long)pos);
75	setmp();
76	}
77
78	/*
79	* Append an integer to the end of the message.
80	*/
81	static void
82	ap_int(n)
83	int n;
84	{
85	sprintf(mp, "%d", n);
86	setmp();
87	}
88
89	/*
90	* Append a string to the end of the message.
91	*/
92	static void
93	ap_str(s)
94	char *s;
95	{
96	strtcpy(mp, s, (unsigned int)(&message[sizeof(message)] - mp));
97	setmp();
98	}
99
100	/*
101	* Append a question mark to the end of the message.
102	*/
103	static void
104	ap_quest()
105	{
106	*mp++ = '?';
107	}
108
109	/*
110	* Return the "current" byte offset in the file.
111	*/
112	static POSITION
113	curr_byte(where)
114	int where;
115	{
116	POSITION pos;
117
118	pos = position(where);
119	while (pos == NULL_POSITION && where >= 0 && where < sc_height)
120	pos = position(++where);
121	if (pos == NULL_POSITION)
122	pos = ch_length();
123	return (pos);
124	}
125
126	/*
127	* Return the value of a prototype conditional.
128	* A prototype string may include conditionals which consist of a
129	* question mark followed by a single letter.
130	* Here we decode that letter and return the appropriate boolean value.
131	*/
132	static int
133	cond(c, where)
134	char c;
135	int where;
136	{
137	switch (c)
138	{
139	case 'a': /* Anything in the message yet? */
140	return (mp > message);
141	case 'b': /* Current byte offset known? */
142	return (curr_byte(where) != NULL_POSITION);
143	case 'e': /* At end of file? */
144	return (hit_eof);
145	case 'f': /* Filename known? */
146	return (strcmp(get_filename(curr_ifile), "-") != 0);
147	case 'l': /* Line number known? */
148	return (linenums);
149	case 'L': /* Final line number known? */
150	return (linenums && ch_length() != NULL_POSITION);
151	case 'm': /* More than one file? */
152	return (nifile() > 1);
153	case 'n': /* First prompt in a new file? */
154	return (new_file);
155	case 'p': /* Percent into file known? */
156	return (curr_byte(where) != NULL_POSITION &&
157	ch_length() > 0);
158	case 's': /* Size of file known? */
159	case 'B':
160	return (ch_length() != NULL_POSITION);
161	case 'x': /* Is there a "next" file? */
162	return (next_ifile(curr_ifile) != NULL_IFILE);
163	}
164	return (0);
165	}
166
167	/*
168	* Decode a "percent" prototype character.
169	* A prototype string may include various "percent" escapes;
170	* that is, a percent sign followed by a single letter.
171	* Here we decode that letter and take the appropriate action,
172	* usually by appending something to the message being built.
173	*/
174	static void
175	protochar(c, where)
176	int c;
177	int where;
178	{
179	POSITION pos;
180	POSITION len;
181	int n;
182	IFILE h;
183
184	switch (c)
185	{
186	case 'b': /* Current byte offset */
187	pos = curr_byte(where);
188	if (pos != NULL_POSITION)
189	ap_pos(pos);
190	else
191	ap_quest();
192	break;
193	#if EDITOR
194	case 'E': /* Editor name */
195	ap_str(editor);
196	break;
197	#endif
198	case 'f': /* File name */
199	ap_str(get_filename(curr_ifile));
200	break;
201	case 'i': /* Index into list of files */
202	ap_int(get_index(curr_ifile));
203	break;
204	case 'l': /* Current line number */
205	n = currline(where);
206	if (n != 0)
207	ap_int(n);
208	else
209	ap_quest();
210	break;
211	case 'L': /* Final line number */
212	len = ch_length();
213	if (len == NULL_POSITION \|\| len == ch_zero() \|\|
214	(n = find_linenum(len)) <= 0)
215	ap_quest();
216	else
217	ap_int(n-1);
218	break;
219	case 'm': /* Number of files */
220	ap_int(nifile());
221	break;
222	case 'p': /* Percent into file */
223	pos = curr_byte(where);
224	len = ch_length();
225	if (pos != NULL_POSITION && len > 0)
226	/*
227	* {{ This calculation may overflow! }}
228	*/
229	ap_int((int)(100*pos / len));
230	else
231	ap_quest();
232	break;
233	case 's': /* Size of file */
234	case 'B':
235	len = ch_length();
236	if (len != NULL_POSITION)
237	ap_pos(len);
238	else
239	ap_quest();
240	break;
241	case 't': /* Truncate trailing spaces in the message */
242	while (mp > message && mp[-1] == ' ')
243	mp--;
244	break;
245	case 'x': /* Name of next file */
246	h = next_ifile(curr_ifile);
247	if (h != NULL_IFILE)
248	ap_str(get_filename(h));
249	else
250	ap_quest();
251	break;
252	}
253	}
254
255	/*
256	* Skip a false conditional.
257	* When a false condition is found (either a false IF or the ELSE part
258	* of a true IF), this routine scans the prototype string to decide
259	* where to resume parsing the string.
260	* We must keep track of nested IFs and skip them properly.
261	*/
262	static char *
263	skipcond(p)
264	register char *p;
265	{
266	register int iflevel;
267
268	/*
269	* We came in here after processing a ? or :,
270	* so we start nested one level deep.
271	*/
272	iflevel = 1;
273
274	for (;;) switch (*++p)
275	{
276	case '?':
277	/*
278	* Start of a nested IF.
279	*/
280	iflevel++;
281	break;
282	case ':':
283	/*
284	* Else.
285	* If this matches the IF we came in here with,
286	* then we're done.
287	*/
288	if (iflevel == 1)
289	return (p);
290	break;
291	case '.':
292	/*
293	* Endif.
294	* If this matches the IF we came in here with,
295	* then we're done.
296	*/
297	if (--iflevel == 0)
298	return (p);
299	break;
300	case '\\':
301	/*
302	* Backslash escapes the next character.
303	*/
304	++p;
305	break;
306	case '\0':
307	/*
308	* Whoops. Hit end of string.
309	* This is a malformed conditional, but just treat it
310	* as if all active conditionals ends here.
311	*/
312	return (p-1);
313	}
314	/NOTREACHED/
315	}
316
317	static char *
318	wherechar(p, wp)
319	char *p;
320	int *wp;
321	{
322	switch (*p)
323	{
324	case 'b': case 'l': case 'p':
325	switch (*++p)
326	{
327	case 't': *wp = TOP; break;
328	case 'm': *wp = MIDDLE; break;
329	case 'b': *wp = BOTTOM; break;
330	case 'B': *wp = BOTTOM_PLUS_ONE; break;
331	case 'j': *wp = adjsline(jump_sline); break;
332	default: *wp = TOP; p--; break;
333	}
334	}
335	return (p);
336	}
337
338	/*
339	* Construct a message based on a prototype string.
340	*/
341	public char *
342	pr_expand(proto, maxwidth)
343	char *proto;
344	int maxwidth;
345	{
346	register char *p;
347	register int c;
348	int where;
349
350	mp = message;
351
352	if (*proto == '\0')
353	return ("");
354
355	for (p = proto; *p != '\0'; p++)
356	{
357	switch (*p)
358	{
359	default: /* Just put the character in the message */
360	mp++ = p;
361	break;
362	case '\\': /* Backslash escapes the next character */
363	p++;
364	mp++ = p;
365	break;
366	case '?': /* Conditional (IF) */
367	if ((c = *++p) == '\0')
368	--p;
369	else
370	{
371	p = wherechar(p, &where);
372	if (!cond(c, where))
373	p = skipcond(p);
374	}
375	break;
376	case ':': /* ELSE */
377	p = skipcond(p);
378	break;
379	case '.': /* ENDIF */
380	break;
381	case '%': /* Percent escape */
382	if ((c = *++p) == '\0')
383	--p;
384	else
385	{
386	p = wherechar(p, &where);
387	protochar(c, where);
388	}
389	break;
390	}
391	}
392
393	new_file = 0;
394	if (mp == message)
395	return (NULL);
396	*mp = '\0';
397	if (maxwidth > 0 && mp >= message + maxwidth)
398	{
399	/*
400	* Message is too long.
401	* Return just the final portion of it.
402	*/
403	return (mp - maxwidth);
404	}
405	return (message);
406	}
407
408	/*
409	* Return a message suitable for printing by the "=" command.
410	*/
411	public char *
412	eq_message()
413	{
414	return (pr_expand(eqproto, 0));
415	}
416
417	/*
418	* Return a prompt.
419	* This depends on the prompt type (SHORT, MEDIUM, LONG), etc.
420	* If we can't come up with an appropriate prompt, return NULL
421	* and the caller will prompt with a colon.
422	*/
423	public char *
424	pr_string()
425	{
426	return (pr_expand(prproto[pr_type], sc_width-so_s_width-so_e_width-2));
427	}