files
kolibrios/programs/develop/ktcc/libc.obj/source/stdlib/strtol.c
Andrew 4f450aa637
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develop/ktcc: Post-SVN tidy
- Move source code from `trunk` into program root directory.
- Update build files and include paths.
- Note: Line endings standardised from `CRLF` > `LF`, so best to view diffs with whitespace changes hidden.
2025-05-24 11:58:48 +01:00

73 lines
1.3 KiB
C

#include <ctype.h>
#include <stdio.h>
#include <stdlib.h>
int getdigit(char ch, int base)
{
if (isdigit(ch))
ch -= '0';
else if (isalpha(ch) && ch <= 'Z')
ch = 10 + ch - 'A';
else if (isalpha(ch))
ch = 10 + ch - 'a';
else
return -1;
if (ch / base != 0)
return -1;
return ch;
}
long int strtol(const char* str, char** endptr, int base)
{
long int res = 0;
int sign = 1;
if (base > 36) {
errno = EINVAL;
goto bye;
}
while (isspace(*str))
str++;
if (*str == '-') {
sign = -1;
str++;
} else if (*str == '+')
str++;
if (base == 0 || base == 16) {
if (*str == '0' && (str[1] == 'x' || str[1] == 'X')) {
base = 16;
str += 2;
}
}
if (base == 0 && *str == '0')
base = 8;
if (base == 0)
base = 10;
int digit;
while ((digit = getdigit(*str, base)) >= 0) {
res = base * res + digit;
str++;
if (res < 0) {
errno = ERANGE;
if (sign > 0)
res = LONG_MAX;
else
res = LONG_MIN;
}
}
bye:
if (endptr)
*endptr = (char*)str;
return res * sign;
}