STRTOUL (3)
convert a string to an unsigned long integer.
SYNOPSIS
#include <stdlib.h>
unsigned long int strtoul(const char * nptr , char ** endptr ,
int base )
DESCRIPTION
The strtoul() function converts the string in nptr to an
unsigned long integer value according to the given base, which
must be between 2 and 36 inclusive, or be the special value 0.
The string must begin with an arbitrary amount of white space (as
determined by
isspace (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 int value
in the obvious manner, stopping at the first character which is not 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 not NULL, strtoul() stores the address of the
first invalid character in *endptr. If there were no digits at
all, strtoul() stores the original value of nptr in
*endptr. (Thus, if *nptr is not `\\0' but **endptr
is `\\0' on return, the entire string is valid.)
RETURN VALUE
The strtoul() function 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 the global
variable errno to ERANGE.
ERRORS
ERANGE
The given string was out of range; the value converted has been clamped.
CONFORMING TO
SVID 3, BSD 4.3, ISO 9899
SEE ALSO
BUGS
Ignores the current locale.
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