curl/lib/strtoofft.c

158 строки
3.6 KiB
C

/***************************************************************************
* _ _ ____ _
* Project ___| | | | _ \| |
* / __| | | | |_) | |
* | (__| |_| | _ <| |___
* \___|\___/|_| \_\_____|
*
* Copyright (C) 1998 - 2004, 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 http://curl.haxx.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.
*
* $Id$
***************************************************************************/
#include "setup.h"
#include "strtoofft.h"
#ifdef NEED_CURL_STRTOLL
#include <stdlib.h>
#include <ctype.h>
#include <errno.h>
static int get_char(char c, int base);
/**
* Emulated version of the strtoll function. This extracts a long long
* value from the given input string and returns it.
*/
curl_off_t
curlx_strtoll(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((int)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 = 0x8000000000000000L;
else
value = 0x7FFFFFFFFFFFFFFFL;
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)
{
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;
}
if (value >= base) {
value = -1;
}
return value;
}
#endif /* Only present if we need strtoll, but don't have it. */