busybox/libbb/xgetularg.c
2006-10-05 10:17:08 +00:00

128 lines
3.1 KiB
C

/* 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"
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;
}
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;
++u; /* two's complement */
}
r = bb_xgetularg_bnd_sfx(p, base, 0, u, suffixes);
if (*arg == '-') {
r = -r;
}
if ((r < lower) || (r > upper)) {
bb_show_usage();
}
return r;
}
long bb_xgetlarg10_sfx(const char *arg, const struct suffix_mult *suffixes)
{
return bb_xgetlarg_bnd_sfx(arg, 10, LONG_MIN, LONG_MAX, suffixes);
}
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);
}
unsigned long bb_xgetularg10_bnd(const char *arg,
unsigned long lower,
unsigned long upper)
{
return bb_xgetularg_bnd(arg, 10, lower, upper);
}
unsigned long bb_xgetularg10(const char *arg)
{
return bb_xgetularg10_bnd(arg, 0, ULONG_MAX);
}