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| #include <stdlib.h> | |
| #include <ctype.h> | |
| #include <limits.h> | |
| #include <errno.h> | |
| /* https://github.com/gcc-mirror/gcc/blob/master/libiberty/strtoul.c */ | |
| unsigned long | |
| strntoul(const char *nptr, size_t n, char **endptr, register int base) | |
| { | |
| register const char *s = nptr; | |
| register size_t mn = n; | |
| register unsigned long acc; | |
| register int c; | |
| register unsigned long cutoff; | |
| register int neg = 0, any, cutlim; | |
| /* | |
| * See strtol for comments as to the logic used. | |
| */ | |
| do { | |
| c = *s++; | |
| /* --mn; */ /* Use if you want to count spaces. */ | |
| } while (isspace(c)); | |
| if (c == '-') { | |
| neg = 1; | |
| c = *s++; | |
| --mn; | |
| } else if (c == '+') { | |
| c = *s++; | |
| --mn; | |
| } | |
| if ((base == 0 || base == 16) && | |
| c == '0' && (*s == 'x' || *s == 'X')) { | |
| c = s[1]; | |
| s += 2; | |
| base = 16; | |
| mn -= 2; /* Maybe not. */ | |
| } | |
| if (base == 0) | |
| base = c == '0' ? 8 : 10; | |
| cutoff = (unsigned long)ULONG_MAX / (unsigned long)base; | |
| cutlim = (unsigned long)ULONG_MAX % (unsigned long)base; | |
| for (acc = 0, any = 0; mn > 0; c = *s++, --mn) { | |
| if (isdigit(c)) | |
| c -= '0'; | |
| else if (isalpha(c)) | |
| c -= isupper(c) ? 'A' - 10 : 'a' - 10; | |
| else | |
| break; | |
| if (c >= base) | |
| break; | |
| if (any < 0 || acc > cutoff || (acc == cutoff && c > cutlim)) | |
| any = -1; | |
| else { | |
| any = 1; | |
| acc *= base; | |
| acc += c; | |
| } | |
| } | |
| if (any < 0) { | |
| acc = ULONG_MAX; | |
| errno = ERANGE; | |
| } else if (neg) | |
| acc = -acc; | |
| if (endptr != 0) | |
| *endptr = (char *) (any ? s - 1 : nptr); | |
| return (acc); | |
| } |
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