88 lines
3.1 KiB
Groff
88 lines
3.1 KiB
Groff
.\" Copyright (c) 1991, 1993
|
|
.\" The Regents of the University of California. All rights reserved.
|
|
.\"
|
|
.\" This code is derived from software contributed to Berkeley by
|
|
.\" the American National Standards Committee X3, on Information
|
|
.\" Processing Systems.
|
|
.\"
|
|
.\" Redistribution and use in source and binary forms, with or without
|
|
.\" modification, are permitted provided that the following conditions
|
|
.\" are met:
|
|
.\" 1. Redistributions of source code must retain the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer.
|
|
.\" 2. Redistributions in binary form must reproduce the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer in the
|
|
.\" documentation and/or other materials provided with the distribution.
|
|
.\" 3. All advertising materials mentioning features or use of this software
|
|
.\" must display the following acknowledgement:
|
|
.\" This product includes software developed by the University of
|
|
.\" California, Berkeley and its contributors.
|
|
.\" 4. Neither the name of the University nor the names of its contributors
|
|
.\" may be used to endorse or promote products derived from this software
|
|
.\" without specific prior written permission.
|
|
.\"
|
|
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
|
|
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
|
|
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
.\" SUCH DAMAGE.
|
|
.\"
|
|
.\" @(#)atof.3 8.1 (Berkeley) 6/4/93
|
|
.\"
|
|
.Dd June 4, 1993
|
|
.Dt ATOF 3
|
|
.Os
|
|
.Sh NAME
|
|
.Nm atof
|
|
.Nd convert
|
|
.Tn ASCII
|
|
string to double
|
|
.Sh SYNOPSIS
|
|
.Fd #include <stdlib.h>
|
|
.Ft double
|
|
.Fn atof "const char *nptr"
|
|
.Sh DESCRIPTION
|
|
The
|
|
.Fn atof
|
|
function converts the initial portion of the string pointed to by
|
|
.Ar nptr
|
|
to
|
|
.Ar double
|
|
representation.
|
|
.Pp
|
|
It is equivalent to:
|
|
.Bd -literal -offset indent
|
|
strtod(nptr, (char **)NULL);
|
|
.Ed
|
|
.Sh SEE ALSO
|
|
.Xr atoi 3 ,
|
|
.Xr atol 3 ,
|
|
.Xr strtod 3 ,
|
|
.Xr strtol 3 ,
|
|
.Xr strtoul 3
|
|
.Sh STANDARDS
|
|
The
|
|
.Fn atof
|
|
function conforms to
|
|
.St -ansiC .
|
|
.Sh BUGS
|
|
This manual page represents intent instead of actual practice.
|
|
While it is intended that
|
|
.Fn atof
|
|
be implemented using
|
|
.Xr strtod 3 ,
|
|
this has not yet happened.
|
|
In the current system,
|
|
.Fn atof
|
|
translates a string in the following form to a double: a string of
|
|
leading white space, possibly followed by a sign (``+'' or ``-''),
|
|
followed by a digit string which may contain one decimal point (``.''),
|
|
which may be followed by either of the exponent flags (``E'' or ``e''),
|
|
and lastly, followed by a signed or unsigned integer.
|