| 0,0 → 1,75 |
|---|
| /* Copyright (C) 1994 DJ Delorie, see COPYING.DJ for details */ |
| #include <limits.h> |
| #include <ctype.h> |
| #include <errno.h> |
| #include <stdlib.h> |
| #include <libc/unconst.h> |
| |
| /* |
| * Convert a string to an unsigned long integer. |
| * |
| * Ignores `locale' stuff. Assumes that the upper and lower case |
| * alphabets and digits are each contiguous. |
| */ |
| unsigned long |
| strtoul(const char *nptr, char **endptr, int base) |
| { |
| const char *s = nptr; |
| unsigned long acc; |
| int c; |
| unsigned long cutoff; |
| int neg = 0, any, cutlim; |
| |
| /* |
| * See strtol for comments as to the logic used. |
| */ |
| do { |
| c = *s++; |
| } while (isspace(c)); |
| if (c == '-') |
| { |
| neg = 1; |
| c = *s++; |
| } |
| else if (c == '+') |
| c = *s++; |
| if ((base == 0 || base == 16) && |
| c == '0' && (*s == 'x' || *s == 'X')) |
| { |
| c = s[1]; |
| s += 2; |
| base = 16; |
| } |
| 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;; c = *s++) |
| { |
| 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 = any ? unconst(s, char *) - 1 : unconst(nptr, char *); |
| return acc; |
| } |