DDI_STRTOUL(9F) | Kernel Functions for Drivers | DDI_STRTOUL(9F) |

#include <sys/ddi.h> #include <sys/sunddi.h>intddi_strtoul(const char *str,char **endptr,intbase,unsigned long *result);

Pointer to a character string to be converted.

*endptr*

Post-conversion final string of unrecognized
characters.

*base*

Radix used for conversion.

*result*

Pointer to variable which contains the converted
value.

The function first decomposes the input string into three parts:

- 1.
- An initial (possibly empty) sequence of white-space characters (' ', '\t', '\n', '\r', '\f')

- 2.
- A subject sequence interpreted as an integer represented in some radix
determined by the value of
*base*

- 3.
- A final string of one or more unrecognized characters, including the terminating null byte of the input string.

The **ddi_strtoul()** function then attempts to convert the
subject sequence to an **unsigned** integer and returns the result.

If the value of *base* is 0, the expected form of the subject
sequence is that of a decimal constant, octal constant or hexadecimal
constant, any of which may be preceded by a plus ("+") or minus
("-") sign. A decimal constant begins with a non-zero digit, and
consists of a sequence of decimal digits. An octal constant consists of the
prefix 0 optionally followed by a sequence of the digits 0 to 7 only. A
hexadecimal constant consists of the prefix 0x or 0X followed by a sequence
of the decimal digits and letters a (or A) to f (or F) with values 10 to 15
respectively.

If the value of *base* is between 2 and 36, the expected form
of the subject sequence is a sequence of letters and digits representing an
integer with the radix specified by *base*, optionally preceded by a
plus or minus sign. The letters from a (or A) to z (or Z) inclusive are
ascribed the values 10 to 35 and only letters whose ascribed values are less
than that of *base* are permitted. If the value of *base* is 16,
the characters 0x or 0X may optionally precede the sequence of letters and
digits, following the sign if present.

The subject sequence is defined as the longest initial subsequence of the input string, starting with the first non-white-space character that is of the expected form. The subject sequence contains no characters if the input string is empty or consists entirely of white-space characters, or if the first non-white-space character is other than a sign or a permissible letter or digit.

If the subject sequence has the expected form and the value of
*base* is 0, the sequence of characters starting with the first digit
is interpreted as an integer constant. If the subject sequence has the
expected form and the value of *base* is between 2 and 36, it is used
as the *base* for conversion, ascribing to each letter its value as
given above. If the subject sequence begins with a minus sign, the value
resulting from the conversion is negated. A pointer to the final string is
stored in the object pointed to by *endptr*, provided that
*endptr* is not a null pointer.

If the subject sequence is empty or does not have the expected
form, no conversion is performed and the value of *str* is stored in
the object pointed to by *endptr*, provided that *endptr* is not a
null pointer.

If the correct value is outside the range of representable values,
**ddi_strtoul()** returns **ERANGE** and the value pointed to by
*result* is not changed.

May 13, 2004 | OmniOS |