STRTOUL

NAME SYNOPSIS DESCRIPTION RETURN VALUE ERRORS CONFORMING TO SEE ALSO BUGS

strtoul - convert a string to an unsigned long integer.

**#include
***nptr***, char *****endptr***,
int** base**)
**

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.)

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.

**ERANGE**

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

SVID 3, BSD 4.3, ISO 9899

atof(3), atoi(3), atol(3), strtod(3), strtol(3)

Ignores the current locale.

16 pages link to strtoul(3):

This page is a man page (or other imported legacy content). We are unable to automatically determine the license status of this page.