Copyright (c) 1990 The Regents of the University of California.
All rights reserved.

This code is derived from software contributed to Berkeley by
Chris Torek.

%sccs.include.redist.man%

@(#)strtoul.3 5.1 (Berkeley) 05/15/90

C 7 strtoul - convert a string to an unsigned long integer #include <stdlib.h>

#include <limits.h>

"unsigned long strtoul(char *nptr, char **endptr, int base);

Strtoul converts the string in nptr to an "unsigned long" value according to the given base , which must be between 2 and 36 inclusive, or be the special value 0.

The string may begin with an arbitrary amount of white space (as determined by isspace ; see ctype (3)), followed by a single optional `+' or `-' sign. If base is zero or 16, the string may then include a `0x' prefix, and the number will be read in base 16; otherwise, a zero base is taken as 10 (decimal) unless the next character is `0', in which case it is taken as 8 (octal).

The remainder of the string is converted to an "unsigned long" value in the obvious manner, stopping at the end of the string or at the first character that does not produce a valid digit in the given base. (In bases above 10, the letter `A' in either upper or lower case represents 10, `B' represents 11, and so forth, with `Z' representing 35.)

If endptr is non nil, strtoul stores the address of the first invalid character in *endptr . If there were no digits at all, however, strtoul stores the original value of nptr in *endptr . (Thus, if *nptr is not '\e0' but **endptr is '\e0' on return, the entire string was valid.)

Strtoul returns either the result of the conversion or, if there was a leading minus sign, the negation of the result of the conversion, unless the original (non-negated) value would overflow; in the latter case, strtoul returns ULONG_MAX and sets errno to ERANGE .

[ERANGE] The given string was out of range; the value converted has been clamped.

strtol(3) Strtoul conforms to ANSI X3.159-1989 (``ANSI C''). Ignores the current locale.