curl/lib/strtoofft.c

243 строки
5.7 KiB
C

/***************************************************************************
* _ _ ____ _
* Project ___| | | | _ \| |
* / __| | | | |_) | |
* | (__| |_| | _ <| |___
* \___|\___/|_| \_\_____|
*
* Copyright (C) 1998 - 2020, Daniel Stenberg, <daniel@haxx.se>, et al.
*
* This software is licensed as described in the file COPYING, which
* you should have received as part of this distribution. The terms
* are also available at https://curl.se/docs/copyright.html.
*
* You may opt to use, copy, modify, merge, publish, distribute and/or sell
* copies of the Software, and permit persons to whom the Software is
* furnished to do so, under the terms of the COPYING file.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
***************************************************************************/
#include <errno.h>
#include "curl_setup.h"
#include "strtoofft.h"
/*
* NOTE:
*
* In the ISO C standard (IEEE Std 1003.1), there is a strtoimax() function we
* could use in case strtoll() doesn't exist... See
* https://www.opengroup.org/onlinepubs/009695399/functions/strtoimax.html
*/
#if (SIZEOF_CURL_OFF_T > SIZEOF_LONG)
# ifdef HAVE_STRTOLL
# define strtooff strtoll
# else
# if defined(_MSC_VER) && (_MSC_VER >= 1300) && (_INTEGRAL_MAX_BITS >= 64)
# if defined(_SAL_VERSION)
_Check_return_ _CRTIMP __int64 __cdecl _strtoi64(
_In_z_ const char *_String,
_Out_opt_ _Deref_post_z_ char **_EndPtr, _In_ int _Radix);
# else
_CRTIMP __int64 __cdecl _strtoi64(const char *_String,
char **_EndPtr, int _Radix);
# endif
# define strtooff _strtoi64
# else
# define PRIVATE_STRTOOFF 1
# endif
# endif
#else
# define strtooff strtol
#endif
#ifdef PRIVATE_STRTOOFF
/* Range tests can be used for alphanum decoding if characters are consecutive,
like in ASCII. Else an array is scanned. Determine this condition now. */
#if('9' - '0') != 9 || ('Z' - 'A') != 25 || ('z' - 'a') != 25
#define NO_RANGE_TEST
static const char valchars[] =
"0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
#endif
static int get_char(char c, int base);
/**
* Custom version of the strtooff function. This extracts a curl_off_t
* value from the given input string and returns it.
*/
static curl_off_t strtooff(const char *nptr, char **endptr, int base)
{
char *end;
int is_negative = 0;
int overflow;
int i;
curl_off_t value = 0;
curl_off_t newval;
/* Skip leading whitespace. */
end = (char *)nptr;
while(ISSPACE(end[0])) {
end++;
}
/* Handle the sign, if any. */
if(end[0] == '-') {
is_negative = 1;
end++;
}
else if(end[0] == '+') {
end++;
}
else if(end[0] == '\0') {
/* We had nothing but perhaps some whitespace -- there was no number. */
if(endptr) {
*endptr = end;
}
return 0;
}
/* Handle special beginnings, if present and allowed. */
if(end[0] == '0' && end[1] == 'x') {
if(base == 16 || base == 0) {
end += 2;
base = 16;
}
}
else if(end[0] == '0') {
if(base == 8 || base == 0) {
end++;
base = 8;
}
}
/* Matching strtol, if the base is 0 and it doesn't look like
* the number is octal or hex, we assume it's base 10.
*/
if(base == 0) {
base = 10;
}
/* Loop handling digits. */
value = 0;
overflow = 0;
for(i = get_char(end[0], base);
i != -1;
end++, i = get_char(end[0], base)) {
newval = base * value + i;
if(newval < value) {
/* We've overflowed. */
overflow = 1;
break;
}
else
value = newval;
}
if(!overflow) {
if(is_negative) {
/* Fix the sign. */
value *= -1;
}
}
else {
if(is_negative)
value = CURL_OFF_T_MIN;
else
value = CURL_OFF_T_MAX;
errno = ERANGE;
}
if(endptr)
*endptr = end;
return value;
}
/**
* Returns the value of c in the given base, or -1 if c cannot
* be interpreted properly in that base (i.e., is out of range,
* is a null, etc.).
*
* @param c the character to interpret according to base
* @param base the base in which to interpret c
*
* @return the value of c in base, or -1 if c isn't in range
*/
static int get_char(char c, int base)
{
#ifndef NO_RANGE_TEST
int value = -1;
if(c <= '9' && c >= '0') {
value = c - '0';
}
else if(c <= 'Z' && c >= 'A') {
value = c - 'A' + 10;
}
else if(c <= 'z' && c >= 'a') {
value = c - 'a' + 10;
}
#else
const char *cp;
int value;
cp = memchr(valchars, c, 10 + 26 + 26);
if(!cp)
return -1;
value = cp - valchars;
if(value >= 10 + 26)
value -= 26; /* Lowercase. */
#endif
if(value >= base) {
value = -1;
}
return value;
}
#endif /* Only present if we need strtoll, but don't have it. */
/*
* Parse a *positive* up to 64 bit number written in ascii.
*/
CURLofft curlx_strtoofft(const char *str, char **endp, int base,
curl_off_t *num)
{
char *end;
curl_off_t number;
errno = 0;
*num = 0; /* clear by default */
while(*str && ISSPACE(*str))
str++;
if('-' == *str) {
if(endp)
*endp = (char *)str; /* didn't actually move */
return CURL_OFFT_INVAL; /* nothing parsed */
}
number = strtooff(str, &end, base);
if(endp)
*endp = end;
if(errno == ERANGE)
/* overflow/underflow */
return CURL_OFFT_FLOW;
else if(str == end)
/* nothing parsed */
return CURL_OFFT_INVAL;
*num = number;
return CURL_OFFT_OK;
}