strto_l_ul.c
1.64 KB
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/* simple replacement of strtol */
#include <stdlib.h>
#include <limits.h>
long long int internal_strtol(const char *nptr, char **endptr, int base)
{
long long int res = 0;
long int dig;
int sign = 0;
do {
/* skip spaces (isspace) */
while (*nptr==' ' || *nptr=='\t' || *nptr=='\n' ||
*nptr=='\v' || *nptr=='\f' || *nptr=='\r') {
nptr++;
}
if (*nptr==0) break;
/* test sign */
if (*nptr=='-' || *nptr=='+') {
if (*nptr=='-') sign = 1;
nptr++;
}
if (*nptr==0) break;
/* select base if base was 0 */
if (base==0 && *nptr=='0') {
nptr++;
if (*nptr==0) break;
if (*nptr=='b') base = 2;
else if (*nptr=='x') base = 16;
else base = 8;
}
if (base==0) base = 10;
/* read digits in the loop */
do {
if (*nptr==0) break;
if (*nptr>='0' && *nptr<='9')
dig = *nptr-'0';
else if (*nptr>='A' && *nptr<='Z')
dig = *nptr - 'A' + 10;
else if (*nptr>='a' && *nptr<='z')
dig = *nptr - 'a' + 10;
else
break;
if (dig<0 || dig>=base) break;
res = res*base + dig;
nptr++;
} while(1);
} while(0);
if (endptr) *endptr = (char *)nptr;
if (sign) res = -res;
return res;
}
long int strtol(const char *nptr, char **endptr, int base)
{
long long ir = internal_strtol(nptr, endptr, base);
if (ir<LONG_MIN) return LONG_MIN;
if (ir>LONG_MAX) return LONG_MAX;
return (long)ir;
}
unsigned long int strtoul(const char *nptr, char **endptr, int base)
{
long long ir = internal_strtol(nptr, endptr, base);
if (ir<0) return 0;
if (ir>ULONG_MAX) return ULONG_MAX;
return (unsigned long) ir;
}