freebsd-skq/lib/libc/stdlib/strtoul.3
Andrey A. Chernov 4e6b157062 Locale *is* used in strto*l*(), at least for isspace(), so remove
'locale not used' statement from comments and BUGS section of manpage.

strtol(): fix non-portable 'cutoff' calculation using the same method as
in strtoll().

Cleanup 'cutoff' calculation, remove unneded casts. Misc. cleanup to
make all functions looks the same.

Implement EINVAL reaction per POSIX, document it in manpage, corresponding
POSIX example quotes here:

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

If no conversion could be performed, 0 shall be returned and errno may be
set to [EINVAL].

[EINVAL] The value of base is not supported.

Since 0, {LONG_MIN} or {LLONG_MIN}, and {LONG_MAX} or {LLONG_MAX} are
returned on error and are also valid returns on success, an application
wishing to check for error situations should set errno to 0, then call
strtol( ) or strtoll ( ), then check errno.
-----------------------------------------------------
2001-09-04 16:39:11 +00:00

197 lines
4.9 KiB
Groff

.\" Copyright (c) 1990, 1991, 1993
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.\" This code is derived from software contributed to Berkeley by
.\" Chris Torek and the American National Standards Committee X3,
.\" on Information Processing Systems.
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.\" @(#)strtoul.3 8.1 (Berkeley) 6/4/93
.\" $FreeBSD$
.\"
.Dd June 4, 1993
.Dt STRTOUL 3
.Os
.Sh NAME
.Nm strtoul , strtoull , strtouq
.Nd "convert a string to an unsigned long, unsigned long long, or uquad_t integer"
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.Fd #include <stdlib.h>
.Fd #include <limits.h>
.Ft unsigned long
.Fn strtoul "const char *nptr" "char **endptr" "int base"
.Ft unsigned long long
.Fn strtoull "const char *nptr" "char **endptr" "int base"
.Fd #include <sys/types.h>
.Fd #include <stdlib.h>
.Fd #include <limits.h>
.Ft u_quad_t
.Fn strtouq "const char *nptr" "char **endptr" "int base"
.Sh DESCRIPTION
The
.Fn strtoul
function
converts the string in
.Fa nptr
to an
.Em unsigned long
value.
The
.Fn strtoull
function
converts the string in
.Fa nptr
to an
.Em unsigned long long
value.
The
.Fn strtouq
function
converts the string in
.Fa nptr
to a
.Em u_quad_t
value.
The conversion is done according to the given
.Fa base ,
which must be between 2 and 36 inclusive,
or be the special value 0.
.Pp
The string may begin with an arbitrary amount of white space
(as determined by
.Xr isspace 3 )
followed by a single optional
.Ql +
or
.Ql -
sign.
If
.Fa base
is zero or 16,
the string may then include a
.Ql 0x
prefix,
and the number will be read in base 16; otherwise, a zero
.Fa base
is taken as 10 (decimal) unless the next character is
.Ql 0 ,
in which case it is taken as 8 (octal).
.Pp
The remainder of the string is converted to an
.Em 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
.Ql A
in either upper or lower case
represents 10,
.Ql B
represents 11, and so forth, with
.Ql Z
representing 35.)
.Pp
If
.Fa endptr
is non nil,
.Fn strtoul
stores the address of the first invalid character in
.Fa *endptr .
If there were no digits at all, however,
.Fn strtoul
stores the original value of
.Fa nptr
in
.Fa *endptr .
(Thus, if
.Fa *nptr
is not
.Ql \e0
but
.Fa **endptr
is
.Ql \e0
on return, the entire string was valid.)
.Sh RETURN VALUES
The
.Fn strtoul
or
.Fn strtoull
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,
.Fn strtoul
returns
.Dv ULONG_MAX
and
.Fn strtoull
returns
.Dv ULLONG_MAX .
In all cases,
.Va errno
is set to
.Er ERANGE .
If no conversion could be performed, 0 shall be returned and
.Va errno
will be
set to
.Er EINVAL .
.Sh ERRORS
.Bl -tag -width Er
.It Bq Er EINVAL
The value of base is not supported or
no conversion could be performed.
.It Bq Er ERANGE
The given string was out of range; the value converted has been clamped.
.El
.Sh SEE ALSO
.Xr strtol 3
.Sh STANDARDS
The
.Fn strtoul
function
conforms to
.St -isoC .
The
.Fn strtoull
function
conforms to
.St -isoC-99 .
The
.Bx
.Fn strtoq
function is deprecated.