busybox/libbb/bb_strtod.c

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/* vi: set sw=4 ts=4: */
/*
* Utility routines.
*
* Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
*
* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
*/
#include "libbb.h"
#include <math.h> /* just for HUGE_VAL */
#define NOT_DIGIT(a) (((unsigned char)(a-'0')) > 9)
double FAST_FUNC bb_strtod(const char *arg, char **endp)
{
double v;
char *endptr;
if (arg[0] != '-' && NOT_DIGIT(arg[0]))
goto err;
errno = 0;
v = strtod(arg, &endptr);
if (endp)
*endp = endptr;
if (endptr[0]) {
/* "1234abcg" or out-of-range? */
if (isalnum(endptr[0]) || errno) {
err:
errno = ERANGE;
return HUGE_VAL;
}
/* good number, just suspicious terminator */
errno = EINVAL;
}
return v;
}
#if 0
/* String to timespec: "NNNN[.NNNNN]" -> struct timespec.
* Can be used for other fixed-point needs.
* Returns pointer past last converted char,
* and returns errno similar to bb_strtoXX functions.
*/
char* FAST_FUNC bb_str_to_ts(struct timespec *ts, const char *arg)
{
if (sizeof(ts->tv_sec) <= sizeof(int))
ts->tv_sec = bb_strtou(arg, &arg, 10);
else if (sizeof(ts->tv_sec) <= sizeof(long))
ts->tv_sec = bb_strtoul(arg, &arg, 10);
else
ts->tv_sec = bb_strtoull(arg, &arg, 10);
ts->tv_nsec = 0;
if (*arg != '.')
return arg;
/* !EINVAL: number is not ok (alphanumeric ending, overflow etc) */
if (errno != EINVAL)
return arg;
if (!*++arg) /* "NNN." */
return arg;
{ /* "NNN.xxx" - parse xxx */
int ndigits;
char *p;
char buf[10]; /* we never use more than 9 digits */
/* Need to make a copy to avoid false overflow */
safe_strncpy(buf, arg, 10);
ts->tv_nsec = bb_strtou(buf, &p, 10);
ndigits = p - buf;
arg += ndigits;
/* normalize to nsec */
while (ndigits < 9) {
ndigits++;
ts->tv_nsec *= 10;
}
while (isdigit(*arg)) /* skip possible 10th plus digits */
arg++;
}
return arg;
}
#endif