stdlib/atof.3

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  36 .\"     @(#)atof.3      8.1 (Berkeley) 6/4/93
  37 .\" $FreeBSD: src/lib/libc/stdlib/atof.3,v 1.16 2002/12/18 13:33:03 ru Exp $
  38 .\"
  39 .Dd June 4, 1993
  40 .Dt ATOF 3
  41 .Os
  42 .Sh NAME
  43 .Nm atof ,
  44 .Nm atof_l
  45 .Nd convert
  46 .Tn ASCII
  47 string to double
  48 .Sh LIBRARY
  49 .Lb libc
  50 .Sh SYNOPSIS
  51 .In stdlib.h
  52 .Ft double
  53 .Fn atof "const char *str"
  54 .In xlocale.h
  55 .Ft double
  56 .Fn atof_l "const char *str" "locale_t loc"
  57 .Sh DESCRIPTION
  58 The
  59 .Fn atof
  60 function converts the initial portion of the string pointed to by
  61 .Fa str
  62 to
  63 .Vt double
  64 representation.
  65 .Pp
  66 It is equivalent to:
  67 .Bd -literal -offset indent
  68 strtod(str, (char **)NULL);
  69 .Ed
  70 .Pp
  71 The decimal point
  72 character is defined in the program's locale (category
  73 .Dv LC_NUMERIC ) .
  74 .Pp
  75 While the
  76 .Fn atof
  77 function uses the current locale, the
  78 .Fn atof_l
  79 function may be passed a locale directly. See
  80 .Xr xlocale 3
  81 for more information.
  82 .Sh IMPLEMENTATION NOTES
  83 The
  84 .Fn atof
  85 function is not thread-safe and also not async-cancel-safe.
  86 .Pp
  87 The
  88 .Fn atof
  89 function has been deprecated by
  90 .Fn strtod
  91 and should not be used in new code.
  92 .Sh ERRORS
  93 The function
  94 .Fn atof
  95 need not affect the value of
  96 .Va errno
  97 on an error.
  98 .Sh SEE ALSO
  99 .Xr atoi 3 ,
 100 .Xr atol 3 ,
 101 .Xr strtod 3 ,
 102 .Xr strtol 3 ,
 103 .Xr strtoul 3 ,
 104 .Xr xlocale 3
 105 .Sh STANDARDS
 106 The
 107 .Fn atof
 108 function conforms to
 109 .St -p1003.1-90 ,
 110 .St -isoC ,
 111 and
 112 .St -isoC-99 .