0f6c6dff74
These functions first appeared in the First Edition of Unix (or earlier in the pdp-7 version). Just claim 1st Edition for all this. The pdp-7 code is too fragmented at this point to extend history that far back.
101 lines
2.8 KiB
Groff
101 lines
2.8 KiB
Groff
.\" Copyright (c) 1991, 1993
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.\" The Regents of the University of California. All rights reserved.
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.\"
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.\" This code is derived from software contributed to Berkeley by
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.\" the American National Standards Committee X3, on Information
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.\" Processing Systems.
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.\"
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.\" Redistribution and use in source and binary forms, with or without
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.\" modification, are permitted provided that the following conditions
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.\" are met:
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.\" 1. Redistributions of source code must retain the above copyright
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.\" notice, this list of conditions and the following disclaimer.
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.\" 2. Redistributions in binary form must reproduce the above copyright
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.\" notice, this list of conditions and the following disclaimer in the
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.\" documentation and/or other materials provided with the distribution.
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.\" 3. Neither the name of the University nor the names of its contributors
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.\" may be used to endorse or promote products derived from this software
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.\" without specific prior written permission.
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.\"
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.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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.\" SUCH DAMAGE.
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.\"
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.\" @(#)atof.3 8.1 (Berkeley) 6/4/93
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.\" $FreeBSD$
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.\"
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.Dd April 1, 2020
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.Dt ATOF 3
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.Os
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.Sh NAME
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.Nm atof
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.Nd convert
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.Tn ASCII
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string to double
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.Sh LIBRARY
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.Lb libc
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.Sh SYNOPSIS
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.In stdlib.h
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.Ft double
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.Fn atof "const char *nptr"
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.Sh DESCRIPTION
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The
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.Fn atof
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function converts the initial portion of the string pointed to by
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.Fa nptr
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to
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.Vt double
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representation.
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.Pp
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It is equivalent to:
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.Bd -literal -offset indent
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strtod(nptr, (char **)NULL);
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.Ed
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.Pp
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The decimal point
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character is defined in the program's locale (category
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.Dv LC_NUMERIC ) .
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.Sh IMPLEMENTATION NOTES
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The
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.Fn atof
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function is not thread-safe and also not async-cancel-safe.
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.Pp
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The
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.Fn atof
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function has been deprecated by
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.Fn strtod
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and should not be used in new code.
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.Sh ERRORS
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The function
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.Fn atof
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need not affect the value of
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.Va errno
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on an error.
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.Sh SEE ALSO
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.Xr atoi 3 ,
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.Xr atol 3 ,
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.Xr strtod 3 ,
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.Xr strtol 3 ,
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.Xr strtoul 3
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.Sh STANDARDS
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The
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.Fn atof
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function conforms to
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.St -p1003.1-90 ,
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.St -isoC ,
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and
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.St -isoC-99 .
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.Sh HISTORY
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The
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.Fn atof
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function appeared in
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.At v1 .
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