STRTOUL(3) BSD Programmer's Manual STRTOUL(3)NAME
strtoul, strtouq - convert a string to an unsigned long or uquad_t
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
The strtoul() 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 deter-
mined 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 charac-
ter 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 conver-
sion, unless the original (non-negated) value would overflow; in the lat-
ter 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 ALSOstrtol(3)STANDARDS
The strtoul() function conforms to ANSI C X3.159-1989 (``ANSI C '').
BUGS
Ignores the current locale.
4.4BSD June 4, 1993 1