xref: /freebsd/lib/libc/stdlib/atof.3 (revision 74bf4e164ba5851606a27d4feff27717452583e5)
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36.\"     @(#)atof.3	8.1 (Berkeley) 6/4/93
37.\" $FreeBSD$
38.\"
39.Dd June 4, 1993
40.Dt ATOF 3
41.Os
42.Sh NAME
43.Nm atof
44.Nd convert
45.Tn ASCII
46string to double
47.Sh LIBRARY
48.Lb libc
49.Sh SYNOPSIS
50.In stdlib.h
51.Ft double
52.Fn atof "const char *nptr"
53.Sh DESCRIPTION
54The
55.Fn atof
56function converts the initial portion of the string pointed to by
57.Fa nptr
58to
59.Vt double
60representation.
61.Pp
62It is equivalent to:
63.Bd -literal -offset indent
64strtod(nptr, (char **)NULL);
65.Ed
66.Pp
67The decimal point
68character is defined in the program's locale (category
69.Dv LC_NUMERIC ) .
70.Sh IMPLEMENTATION NOTES
71The
72.Fn atof
73function is not thread-safe and also not async-cancel-safe.
74.Pp
75The
76.Fn atof
77function has been deprecated by
78.Fn strtod
79and should not be used in new code.
80.Sh ERRORS
81The function
82.Fn atof
83need not affect the value of
84.Va errno
85on an error.
86.Sh SEE ALSO
87.Xr atoi 3 ,
88.Xr atol 3 ,
89.Xr strtod 3 ,
90.Xr strtol 3 ,
91.Xr strtoul 3
92.Sh STANDARDS
93The
94.Fn atof
95function conforms to
96.St -p1003.1-90 ,
97.St -isoC ,
98and
99.St -isoC-99 .
100