NAME
strtoul, strtouq —
convert a string to an unsigned long or
uquad_t integer
SYNOPSIS
#include
<stdlib.h>
#include <limits.h>
unsigned long
strtoul(const
char *nptr, char
**endptr, int
base);
#include <sys/types.h>
#include <stdlib.h>
#include <limits.h>
u_quad_t
strtouq(const
char *nptr, char
**endptr, int
base);
DESCRIPTION
Thestrtoul()
function converts the string in nptr to an
unsigned long value. The
strtouq()
function converts the string in nptr to a
u_quad_t
value. The conversion is done 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(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
‘\0’ but
**endptr is ‘\0’
on return, the entire string was valid.)
RETURN VALUES
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.
SEE ALSO
STANDARDS
The strtoul() function conforms to
ANSI X3.159-1989
(“ANSI C89”).
BUGS
Ignores the current locale.