summaryrefslogtreecommitdiff
path: root/libbb/xgetularg.c
blob: 6110746a53c9774d1b590810fe808a0da32c99a2 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
/* vi: set sw=4 ts=4: */
/*
 * xgetularg* implementations for busybox
 *
 * Copyright (C) 2003  Manuel Novoa III  <mjn3@codepoet.org>
 *
 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
 */

#include <stdlib.h>
#include <string.h>
#include <limits.h>
#include <ctype.h>
#include <errno.h>
#include <assert.h>
#include "libbb.h"

#ifdef L_xgetularg_bnd_sfx
unsigned long bb_xgetularg_bnd_sfx(const char *arg, int base,
								   unsigned long lower,
								   unsigned long upper,
								   const struct suffix_mult *suffixes)
{
	unsigned long r;
	int old_errno;
	char *e;

	assert(arg);

	/* Disallow '-' and any leading whitespace.  Speed isn't critical here
	 * since we're parsing commandline args.  So make sure we get the
	 * actual isspace function rather than a larger macro implementaion. */
	if ((*arg == '-') || (isspace)(*arg)) {
		bb_show_usage();
	}

	/* Since this is a lib function, we're not allowed to reset errno to 0.
	 * Doing so could break an app that is deferring checking of errno.
	 * So, save the old value so that we can restore it if successful. */
	old_errno = errno;
	errno = 0;
	r = strtoul(arg, &e, base);
	/* Do the initial validity check.  Note: The standards do not
	 * guarantee that errno is set if no digits were found.  So we
	 * must test for this explicitly. */
	if (errno || (arg == e)) {	/* error or no digits */
		bb_show_usage();
	}
	errno = old_errno;	/* Ok.  So restore errno. */

	/* Do optional suffix parsing.  Allow 'empty' suffix tables.
	 * Note that we also all nul suffixes with associated multipliers,
	 * to allow for scaling of the arg by some default multiplier. */

	if (suffixes) {
		while (suffixes->suffix) {
			if (strcmp(suffixes->suffix, e) == 0) {
				if (ULONG_MAX / suffixes->mult < r) {	/* Overflow! */
					bb_show_usage();
				}
				++e;
				r *= suffixes->mult;
				break;
			}
			++suffixes;
		}
	}

	/* Finally, check for illegal trailing chars and range limits. */
	/* Note: although we allow leading space (via stroul), trailing space
	 * is an error.  It would be easy enough to allow though if desired. */
	if (*e || (r < lower) || (r > upper)) {
		bb_show_usage();
	}

	return r;
}
#endif

#ifdef L_xgetlarg_bnd_sfx
long bb_xgetlarg_bnd_sfx(const char *arg, int base,
						 long lower,
						 long upper,
						 const struct suffix_mult *suffixes)
{
	unsigned long u = LONG_MAX;
	long r;
	const char *p = arg;

	if ((*p == '-') && (p[1] != '+')) {
		++p;
#if LONG_MAX == (-(LONG_MIN + 1))
		++u;	/* two's complement */
#endif
	}

	r = bb_xgetularg_bnd_sfx(p, base, 0, u, suffixes);

	if (*arg == '-') {
		r = -r;
	}

	if ((r < lower) || (r > upper)) {
		bb_show_usage();
	}

	return r;
}
#endif

#ifdef L_getlarg10_sfx
long bb_xgetlarg10_sfx(const char *arg, const struct suffix_mult *suffixes)
{
	return bb_xgetlarg_bnd_sfx(arg, 10, LONG_MIN, LONG_MAX, suffixes);
}
#endif

#ifdef L_xgetularg_bnd
unsigned long bb_xgetularg_bnd(const char *arg, int base,
							   unsigned long lower,
							   unsigned long upper)
{
	return bb_xgetularg_bnd_sfx(arg, base, lower, upper, NULL);
}
#endif

#ifdef L_xgetularg10_bnd
unsigned long bb_xgetularg10_bnd(const char *arg,
								 unsigned long lower,
								 unsigned long upper)
{
	return bb_xgetularg_bnd(arg, 10, lower, upper);
}
#endif

#ifdef L_xgetularg10
unsigned long bb_xgetularg10(const char *arg)
{
	return bb_xgetularg10_bnd(arg, 0, ULONG_MAX);
}
#endif