[apple/libc.git] / stdlib / FreeBSD / atof.3

.\" 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
.\" $FreeBSD: src/lib/libc/stdlib/atof.3,v 1.16 2002/12/18 13:33:03 ru Exp $
.\"
.Dd June 4, 1993
.Dt ATOF 3
.Os
.Sh NAME
.Nm atof
.Nd convert
.Tn ASCII
string to double
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.In 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
.Fa nptr
to
.Vt double
representation.
.Pp
It is equivalent to:
.Bd -literal -offset indent
strtod(nptr, (char **)NULL);
.Ed
.Pp
The decimal point
character is defined in the program's locale (category
.Dv LC_NUMERIC ) .
.Sh IMPLEMENTATION NOTES
The
.Fn atof
function is not thread-safe and also not async-cancel-safe.
.Pp
The
.Fn atof
function has been deprecated by
.Fn strtod
and should not be used in new code.
.Sh ERRORS
The function
.Fn atof
need not affect the value of
.Va errno
on an error.
.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 -p1003.1-90 ,
.St -isoC ,
and
.St -isoC-99 .
Commit	Line	Data
e9ce8d39 A	1	.\" Copyright (c) 1991, 1993
	2	.\" The Regents of the University of California. All rights reserved.
	3	.\"
5b2abdfb A	4	.\" This code is derived from software contributed to Berkeley by
	5	.\" the American National Standards Committee X3, on Information
	6	.\" Processing Systems.
	7	.\"
e9ce8d39 A	8	.\" Redistribution and use in source and binary forms, with or without
	9	.\" modification, are permitted provided that the following conditions
	10	.\" are met:
	11	.\" 1. Redistributions of source code must retain the above copyright
	12	.\" notice, this list of conditions and the following disclaimer.
	13	.\" 2. Redistributions in binary form must reproduce the above copyright
	14	.\" notice, this list of conditions and the following disclaimer in the
	15	.\" documentation and/or other materials provided with the distribution.
	16	.\" 3. All advertising materials mentioning features or use of this software
	17	.\" must display the following acknowledgement:
	18	.\" This product includes software developed by the University of
	19	.\" California, Berkeley and its contributors.
	20	.\" 4. Neither the name of the University nor the names of its contributors
	21	.\" may be used to endorse or promote products derived from this software
	22	.\" without specific prior written permission.
	23	.\"
	24	.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	25	.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	26	.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	27	.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	28	.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	29	.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	30	.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	31	.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	32	.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	33	.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	34	.\" SUCH DAMAGE.
	35	.\"
5b2abdfb	36	.\" @(#)atof.3 8.1 (Berkeley) 6/4/93
9385eb3d	37	.\" $FreeBSD: src/lib/libc/stdlib/atof.3,v 1.16 2002/12/18 13:33:03 ru Exp $
e9ce8d39	38	.\"
5b2abdfb A	39	.Dd June 4, 1993
5b2abdfb A	40	.Dt ATOF 3
e9ce8d39 A	41	.Os
e9ce8d39 A	42	.Sh NAME
5b2abdfb A	43	.Nm atof
	44	.Nd convert
	45	.Tn ASCII
	46	string to double
e9ce8d39 A	47	.Sh LIBRARY
	48	.Lb libc
	49	.Sh SYNOPSIS
5b2abdfb A	50	.In stdlib.h
	51	.Ft double
	52	.Fn atof "const char *nptr"
e9ce8d39 A	53	.Sh DESCRIPTION
e9ce8d39 A	54	The
5b2abdfb A	55	.Fn atof
5b2abdfb A	56	function converts the initial portion of the string pointed to by
9385eb3d	57	.Fa nptr
5b2abdfb	58	to
9385eb3d	59	.Vt double
5b2abdfb A	60	representation.
	61	.Pp
	62	It is equivalent to:
	63	.Bd -literal -offset indent
	64	strtod(nptr, (char **)NULL);
e9ce8d39	65	.Ed
5b2abdfb A	66	.Pp
	67	The decimal point
	68	character is defined in the program's locale (category
	69	.Dv LC_NUMERIC ) .
	70	.Sh IMPLEMENTATION NOTES
	71	The
	72	.Fn atof
	73	function is not thread-safe and also not async-cancel-safe.
	74	.Pp
	75	The
	76	.Fn atof
	77	function has been deprecated by
	78	.Fn strtod
	79	and should not be used in new code.
e9ce8d39	80	.Sh ERRORS
9385eb3d	81	The function
5b2abdfb	82	.Fn atof
9385eb3d A	83	need not affect the value of
	84	.Va errno
	85	on an error.
e9ce8d39	86	.Sh SEE ALSO
5b2abdfb A	87	.Xr atoi 3 ,
	88	.Xr atol 3 ,
	89	.Xr strtod 3 ,
	90	.Xr strtol 3 ,
	91	.Xr strtoul 3
	92	.Sh STANDARDS
e9ce8d39	93	The
5b2abdfb A	94	.Fn atof
	95	function conforms to
	96	.St -p1003.1-90 ,
	97	.St -isoC ,
	98	and
	99	.St -isoC-99 .