stdlib/FreeBSD/atof.3

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  32 .\"     @(#)atof.3      8.1 (Berkeley) 6/4/93
  33 .\" $FreeBSD: src/lib/libc/stdlib/atof.3,v 1.17 2007/01/09 00:28:09 imp Exp $
  34 .\"
  35 .Dd June 4, 1993
  36 .Dt ATOF 3
  37 .Os
  38 .Sh NAME
  39 .Nm atof
  40 .Nd convert
  41 .Tn ASCII
  42 string to double
  43 .Sh LIBRARY
  44 .Lb libc
  45 .Sh SYNOPSIS
  46 .In stdlib.h
  47 .Ft double
  48 .Fn atof "const char *nptr"
  49 .Sh DESCRIPTION
  50 The
  51 .Fn atof
  52 function converts the initial portion of the string pointed to by
  53 .Fa nptr
  54 to
  55 .Vt double
  56 representation.
  57 .Pp
  58 It is equivalent to:
  59 .Bd -literal -offset indent
  60 strtod(nptr, (char **)NULL);
  61 .Ed
  62 .Pp
  63 The decimal point
  64 character is defined in the program's locale (category
  65 .Dv LC_NUMERIC ) .
  66 .Sh IMPLEMENTATION NOTES
  67 The
  68 .Fn atof
  69 function is not thread-safe and also not async-cancel-safe.
  70 .Pp
  71 The
  72 .Fn atof
  73 function has been deprecated by
  74 .Fn strtod
  75 and should not be used in new code.
  76 .Sh ERRORS
  77 The function
  78 .Fn atof
  79 need not affect the value of
  80 .Va errno
  81 on an error.
  82 .Sh SEE ALSO
  83 .Xr atoi 3 ,
  84 .Xr atol 3 ,
  85 .Xr strtod 3 ,
  86 .Xr strtol 3 ,
  87 .Xr strtoul 3
  88 .Sh STANDARDS
  89 The
  90 .Fn atof
  91 function conforms to
  92 .St -p1003.1-90 ,
  93 .St -isoC ,
  94 and
  95 .St -isoC-99 .