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.\" Copyright (c) 2001-2003 The Open Group, All Rights Reserved 

.TH "STRTOUL" P 2003 "IEEE/The Open Group" "POSIX Programmer's Manual"

.\" strtoul 

.SH NAME

strtoul, strtoull \- convert a string to an unsigned long

.SH SYNOPSIS

.LP

\fB#include <stdlib.h>

.br

.sp

unsigned long strtoul(const char *restrict\fP \fIstr\fP\fB,

.br

\ \ \ \ \ \  char **restrict\fP \fIendptr\fP\fB, int\fP \fIbase\fP\fB);

.br

unsigned long long strtoull(const char *restrict\fP \fIstr\fP\fB,

.br

\ \ \ \ \ \  char **restrict\fP \fIendptr\fP\fB, int\fP \fIbase\fP\fB);

.br

\fP

.SH DESCRIPTION

.LP

These functions shall convert the initial portion of the string pointed

to by \fIstr\fP to a type \fBunsigned long\fP and

\fBunsigned long long\fP representation, respectively. First, they

decompose the input string into three parts:

.IP " 1." 4

An initial, possibly empty, sequence of white-space characters (as

specified by \fIisspace\fP())

.LP

.IP " 2." 4

A subject sequence interpreted as an integer represented in some radix

determined by the value of \fIbase\fP

.LP

.IP " 3." 4

A final string of one or more unrecognized characters, including the

terminating null byte of the input string

.LP

.LP

Then they shall attempt to convert the subject sequence to an unsigned

integer, and return the result.

.LP

If the value of \fIbase\fP 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 \fB'+'\fP

or \fB'-'\fP 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 \fB'0'\fP optionally

followed by a sequence of the digits \fB'0'\fP to \fB'7'\fP only.

A hexadecimal constant consists of the prefix 0x or 0X

followed by a sequence of the decimal digits and letters \fB'a'\fP

(or \fB'A'\fP ) to \fB'f'\fP (or \fB'F'\fP ) with

values 10 to 15 respectively.

.LP

If the value of \fIbase\fP 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 \fIbase\fP, optionally

preceded by a \fB'+'\fP or \fB'-'\fP sign. The

letters from \fB'a'\fP (or \fB'A'\fP ) to \fB'z'\fP (or \fB'Z'\fP

) inclusive are ascribed the values 10 to 35; only

letters whose ascribed values are less than that of \fIbase\fP are

permitted. If the value of \fIbase\fP is 16, the characters 0x

or 0X may optionally precede the sequence of letters and digits, following

the sign if present.

.LP

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 shall

contain 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.

.LP

If the subject sequence has the expected form and the value of \fIbase\fP

is 0, the sequence of characters starting with the

first digit shall be interpreted as an integer constant. If the subject

sequence has the expected form and the value of \fIbase\fP

is between 2 and 36, it shall be 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

shall be negated. A pointer to the final string shall be

stored in the object pointed to by \fIendptr\fP, provided that \fIendptr\fP

is not a null pointer.

.LP

In other than the C   \ or POSIX  locales, other

implementation-defined subject sequences may be accepted.

.LP

If the subject sequence is empty or does not have the expected form,

no conversion shall be performed; the value of \fIstr\fP

shall be stored in the object pointed to by \fIendptr\fP, provided

that \fIendptr\fP is not a null pointer.

.LP

The

\fIstrtoul\fP() function shall not change the setting of \fIerrno\fP

if successful.

.LP

Since 0, {ULONG_MAX}, and {ULLONG_MAX} are returned on error and are

also valid returns on success, an application wishing to

check for error situations should set \fIerrno\fP to 0, then call

\fIstrtoul\fP() or \fIstrtoull\fP(), then check \fIerrno\fP.

.SH RETURN VALUE

.LP

Upon successful completion, these functions shall return the converted

value, if any. If no conversion could be performed, 0

shall be returned   \ and \fIerrno\fP may be set to [EINVAL].  If

the

correct value is outside the range of representable values, {ULONG_MAX}

or {ULLONG_MAX} shall be returned and \fIerrno\fP set to

[ERANGE].

.SH ERRORS

.LP

These functions shall fail if:

.TP 7

.B EINVAL

The value of \fIbase\fP is not supported. 

.TP 7

.B ERANGE

The value to be returned is not representable.

.sp

.LP

These functions may fail if:

.TP 7

.B EINVAL

No

conversion could be performed. 

.sp

.LP

\fIThe following sections are informative.\fP

.SH EXAMPLES

.LP

None.

.SH APPLICATION USAGE

.LP

None.

.SH RATIONALE

.LP

None.

.SH FUTURE DIRECTIONS

.LP

None.

.SH SEE ALSO

.LP

\fIisalpha\fP() , \fIscanf\fP() , \fIstrtod\fP() , \fIstrtol\fP()

, the Base Definitions volume of

IEEE\ Std\ 1003.1-2001, \fI<stdlib.h>\fP

.SH COPYRIGHT

Portions of this text are reprinted and reproduced in electronic form

from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology

-- Portable Operating System Interface (POSIX), The Open Group Base

Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of

Electrical and Electronics Engineers, Inc and The Open Group. In the

event of any discrepancy between this version and the original IEEE and

The Open Group Standard, the original IEEE and The Open Group Standard

is the referee document. The original Standard can be obtained online at

http://www.opengroup.org/unix/online.html .