io.c revision 1.25 
1/*	$OpenBSD: io.c,v 1.25 2016/01/27 00:03:52 krw Exp $	*/
2
3/*
4 * io.c - simple io and input parsing routines
5 *
6 * Written by Eryk Vershen
7 */
8
9/*
10 * Copyright 1996,1997,1998 by Apple Computer, Inc.
11 *              All Rights Reserved
12 *
13 * Permission to use, copy, modify, and distribute this software and
14 * its documentation for any purpose and without fee is hereby granted,
15 * provided that the above copyright notice appears in all copies and
16 * that both the copyright notice and this permission notice appear in
17 * supporting documentation.
18 *
19 * APPLE COMPUTER DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE
20 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
21 * FOR A PARTICULAR PURPOSE.
22 *
23 * IN NO EVENT SHALL APPLE COMPUTER BE LIABLE FOR ANY SPECIAL, INDIRECT, OR
24 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
25 * LOSS OF USE, DATA OR PROFITS, WHETHER IN ACTION OF CONTRACT,
26 * NEGLIGENCE, OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
27 * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
28 */
29
30#include <err.h>
31#include <stdio.h>
32#include <stdlib.h>
33#include <string.h>
34#include <stdarg.h>
35
36#include "dpme.h"
37#include "io.h"
38
39#define BAD_DIGIT 17		/* must be greater than any base */
40#define UNGET_MAX_COUNT 10
41
42short	unget_buf[UNGET_MAX_COUNT + 1];
43int	unget_count;
44
45static long	get_number(int);
46static char    *get_string(int);
47static int	my_getch (void);
48
49int
50my_getch()
51{
52	if (unget_count > 0)
53		return (unget_buf[--unget_count]);
54	else
55		return (getc(stdin));
56}
57
58
59void
60my_ungetch(int c)
61{
62	/*
63         * In practice there is never more than one character in
64         * the unget_buf, but what's a little overkill among friends?
65         */
66	if (unget_count < UNGET_MAX_COUNT)
67		unget_buf[unget_count++] = c;
68	else
69		errx(1, "Programmer error in my_ungetch().");
70}
71
72void
73flush_to_newline(int keep_newline)
74{
75	int c;
76
77	for (;;) {
78		c = my_getch();
79
80		if (c <= 0) {
81			break;
82		} else if (c == '\n') {
83			if (keep_newline) {
84				my_ungetch(c);
85			}
86			break;
87		} else {
88			/* skip */
89		}
90	}
91	return;
92}
93
94
95int
96get_okay(const char *prompt, int default_value)
97{
98	int c;
99
100	flush_to_newline(0);
101	printf(prompt);
102
103	for (;;) {
104		c = my_getch();
105
106		if (c <= 0) {
107			break;
108		} else if (c == ' ' || c == '\t') {
109			/* skip blanks and tabs */
110		} else if (c == '\n') {
111			my_ungetch(c);
112			return default_value;
113		} else if (c == 'y' || c == 'Y') {
114			return 1;
115		} else if (c == 'n' || c == 'N') {
116			return 0;
117		} else {
118			flush_to_newline(0);
119			printf(prompt);
120		}
121	}
122	return -1;
123}
124
125int
126get_command(const char *prompt, int promptBeforeGet, int *command)
127{
128	int c;
129
130	if (promptBeforeGet)
131		printf(prompt);
132
133	for (;;) {
134		c = my_getch();
135
136		if (c <= 0) {
137			break;
138		} else if (c == ' ' || c == '\t') {
139			/* skip blanks and tabs */
140		} else if (c == '\n') {
141			printf(prompt);
142		} else {
143			*command = c;
144			return 1;
145		}
146	}
147	return 0;
148}
149
150int
151get_number_argument(const char *prompt, long *number)
152{
153	int c;
154	int result = 0;
155
156	for (;;) {
157		c = my_getch();
158
159		if (c <= 0) {
160			break;
161		} else if (c == ' ' || c == '\t') {
162			/* skip blanks and tabs */
163		} else if (c == '\n') {
164			printf(prompt);
165		} else if ('0' <= c && c <= '9') {
166			*number = get_number(c);
167			result = 1;
168			break;
169		} else {
170			my_ungetch(c);
171			*number = 0;
172			break;
173		}
174	}
175	return result;
176}
177
178
179long
180get_number(int first_char)
181{
182	int c, base, digit, ret_value;
183
184	if (first_char != '0') {
185		c = first_char;
186		base = 10;
187		digit = BAD_DIGIT;
188	} else if ((c = my_getch()) == 'x' || c == 'X') {
189		c = my_getch();
190		base = 16;
191		digit = BAD_DIGIT;
192	} else {
193		my_ungetch(c);
194		c = first_char;
195		base = 8;
196		digit = 0;
197	}
198	ret_value = 0;
199	for (ret_value = 0;; c = my_getch()) {
200		if (c >= '0' && c <= '9')
201			digit = c - '0';
202		else if (c >= 'A' && c <= 'F')
203			digit = 10 + (c - 'A');
204		else if (c >= 'a' && c <= 'f')
205			digit = 10 + (c - 'a');
206		else
207			digit = BAD_DIGIT;
208		if (digit >= base)
209			break;
210		ret_value = ret_value * base + digit;
211	}
212	my_ungetch(c);
213	return (ret_value);
214}
215
216char *
217get_dpistr_argument(const char *prompt)
218{
219	int c;
220
221	for (;;) {
222		c = my_getch();
223
224		if (c <= 0) {
225			break;
226		} else if (c == ' ' || c == '\t') {
227			/* skip blanks and tabs */
228		} else if (c == '\n') {
229			printf(prompt);
230		} else if (c == '"' || c == '\'') {
231			return get_string(c);
232		} else if (('a' <= c && c <= 'z') || ('A' <= c && c <= 'Z') ||
233		    (c == '-' || c == '/' || c == '.' || c == ':')) {
234			my_ungetch(c);
235			return get_string(' ');
236		} else {
237			my_ungetch(c);
238			return NULL;
239		}
240	}
241	return NULL;
242}
243
244
245char *
246get_string(int eos)
247{
248	char buf[DPISTRLEN];
249	char *s, *limit;
250	int c;
251
252	memset(buf, 0, sizeof(buf));
253	limit = buf + sizeof(buf);
254
255	c = my_getch();
256	for (s = buf;; c = my_getch()) {
257		if (c <= 0 || c == eos || (eos == ' ' && c == '\t')) {
258			*s = 0;
259			break;
260		} else if (c == '\n') {
261			*s = 0;
262			my_ungetch(c);
263			break;
264		} else {
265			*s++ = c;
266			if (s >= limit)
267				return NULL;
268		}
269	}
270	return (strdup(buf));
271}
272
273
274unsigned long
275get_multiplier(long divisor)
276{
277	unsigned long result, extra;
278	int c;
279
280	c = my_getch();
281
282	extra = 1;
283	if (c <= 0 || divisor <= 0) {
284		result = 0;
285	} else if (c == 't' || c == 'T') {
286		result = 1024 * 1024;
287		extra = 1024 * 1024;
288	} else if (c == 'g' || c == 'G') {
289		result = 1024 * 1024 * 1024;
290	} else if (c == 'm' || c == 'M') {
291		result = 1024 * 1024;
292	} else if (c == 'k' || c == 'K') {
293		result = 1024;
294	} else {
295		my_ungetch(c);
296		result = 1;
297	}
298	if (result > 1) {
299		if (extra > 1) {
300			result /= divisor;
301			if (result >= 4096) {
302				/* overflow -> 20bits + >12bits */
303				result = 0;
304			} else {
305				result *= extra;
306			}
307		} else if (result >= divisor) {
308			result /= divisor;
309		} else {
310			result = 1;
311		}
312	}
313	return result;
314}
315
316
317int
318get_partition_modifier(void)
319{
320	int c, result;
321
322	result = 0;
323
324	c = my_getch();
325
326	if (c == 'p' || c == 'P')
327		result = 1;
328	else if (c > 0)
329		my_ungetch(c);
330
331	return result;
332}
333
334
335int
336number_of_digits(unsigned long value)
337{
338	int j;
339
340	j = 1;
341	while (value > 9) {
342		j++;
343		value = value / 10;
344	}
345	return j;
346}
347
348
349/*
350 * Print a message on standard error & flush the input.
351 */
352void
353bad_input(const char *fmt,...)
354{
355	va_list ap;
356
357	va_start(ap, fmt);
358	vfprintf(stderr, fmt, ap);
359	va_end(ap);
360	fprintf(stderr, "\n");
361	flush_to_newline(1);
362}
363