.\" Copyright (c) 1990 The Regents of the University of California.
.\" All rights reserved.
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.\" developed by the University of California, Berkeley and its contributors''
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.\"	@(#)atof.3	6.2 (Berkeley) 5/16/90
.\"
.TH ATOF 3 "May 16, 1990"
.UC 7
.SH NAME
atof \- convert ASCII string to double
.SH SYNOPSIS
.nf
.ft B
#include <stdlib.h>

double
atof(const char *nptr);
.ft R
.fi
.SH DESCRIPTION
The
.I atof
function converts the initial portion of the string pointed to by
.I nptr
to
.I double
representation.
.PP
It is equivalent to:
.sp
.RS
strtod(nptr, (char **)NULL);
.RE
.SH SEE ALSO
atoi(3), atol(3), strtod(3), strtol(3), strtoul(3)
.SH STANDARDS
.B Atof
conforms to ANSI X3.159-1989 (``ANSI C'').
.SH BUGS
This manual page represents intent instead of actual practice.
While it is intended that
.I atof
be implemented using
.IR strtod (3),
this has not yet happened.
In the current system,
.I atof
translates a string in the following form to a double:
an optional string of spaces, followed by an optional sign (``+'' or ``-''),
followed by a string of digits which may contain a decimal point (``.''),
followed by an optional exponent flag (``E'' or ``e''), followed by an
optionally signed integer.