1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
|
.\" Copyright 2004 Andries Brouwer <aeb@cwi.nl>.
.\"
.\" %%%LICENSE_START(VERBATIM)
.\" Permission is granted to make and distribute verbatim copies of this
.\" manual provided the copyright notice and this permission notice are
.\" preserved on all copies.
.\"
.\" Permission is granted to copy and distribute modified versions of this
.\" manual under the conditions for verbatim copying, provided that the
.\" entire resulting derived work is distributed under the terms of a
.\" permission notice identical to this one.
.\"
.\" Since the Linux kernel and libraries are constantly changing, this
.\" manual page may be incorrect or out-of-date. The author(s) assume no
.\" responsibility for errors or omissions, or for damages resulting from
.\" the use of the information contained herein. The author(s) may not
.\" have taken the same level of care in the production of this manual,
.\" which is licensed free of charge, as they might when working
.\" professionally.
.\"
.\" Formatted or processed versions of this manual, if unaccompanied by
.\" the source, must acknowledge the copyright and authors of this work.
.\" %%%LICENSE_END
.\"
.TH FINITE 3 2017-09-15 "" "Linux Programmer's Manual"
.SH NAME
finite, finitef, finitel, isinf, isinff, isinfl, isnan, isnanf, isnanl \-
BSD floating-point classification functions
.SH SYNOPSIS
.nf
.B #include <math.h>
.PP
.BI "int finite(double " x );
.BI "int finitef(float " x );
.BI "int finitel(long double " x );
.PP
.BI "int isinf(double " x );
.BI "int isinff(float " x );
.BI "int isinfl(long double " x );
.PP
.BI "int isnan(double " x );
.BI "int isnanf(float " x );
.BI "int isnanl(long double " x );
.fi
.PP
.RS -4
Feature Test Macro Requirements for glibc (see
.BR feature_test_macros (7)):
.RE
.PP
.ad l
.BR finite (),
.BR finitef (),
.BR finitel ():
.RS 4
/* Glibc since 2.19: */ _DEFAULT_SOURCE
|| /* Glibc versions <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE
.RE
.BR isinf ():
.RS 4
_XOPEN_SOURCE\ >=\ 600 || _ISOC99_SOURCE
|| /* Glibc since 2.19: */ _DEFAULT_SOURCE
|| /* Glibc versions <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE
.RE
.br
.BR isinff (),
.BR isinfl ():
.RS 4
/* Glibc since 2.19: */ _DEFAULT_SOURCE
|| /* Glibc versions <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE
.RE
.BR isnan ():
.RS 4
_XOPEN_SOURCE || _ISOC99_SOURCE
|| /* Glibc since 2.19: */ _DEFAULT_SOURCE
|| /* Glibc versions <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE
.RE
.BR isnanf (),
.BR isnanl ():
.RS 4
_XOPEN_SOURCE\ >=\ 600
|| /* Glibc since 2.19: */ _DEFAULT_SOURCE
|| /* Glibc versions <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE
.RE
.ad b
.SH DESCRIPTION
The
.BR finite (),
.BR finitef (),
and
.BR finitel ()
functions return a nonzero value if
.I x
is neither infinite
nor a "not-a-number" (NaN) value, and 0 otherwise.
.PP
The
.BR isnan (),
.BR isnanf (),
and
.BR isnanl ()
functions return a nonzero value if
.I x
is a NaN value,
and 0 otherwise.
.PP
The
.BR isinf (),
.BR isinff (),
and
.BR isinfl ()
functions return 1 if
.I x
is positive infinity, \-1 if
.I x
is negative infinity, and 0 otherwise.
.SH ATTRIBUTES
For an explanation of the terms used in this section, see
.BR attributes (7).
.TS
allbox;
lbw31 lb lb
l l l.
Interface Attribute Value
T{
.BR finite (),
.BR finitef (),
.BR finitel (),
.br
.BR isinf (),
.BR isinff (),
.BR isinfl (),
.br
.BR isnan (),
.BR isnanf (),
.BR isnanl ()
T} Thread safety MT-Safe
.TE
.SH NOTES
Note that these functions are obsolete.
C99 defines macros
.BR isfinite (),
.BR isinf (),
and
.BR isnan ()
(for all types) replacing them.
Further note that the C99
.BR isinf ()
has weaker guarantees on the return value.
See
.BR fpclassify (3).
.\"
.\" finite* not on HP-UX; they exist on Tru64.
.\" .SH HISTORY
.\" The
.\" .BR finite ()
.\" function occurs in 4.3BSD.
.\" see IEEE.3 in the 4.3BSD manual
.SH SEE ALSO
.BR fpclassify (3)
.SH COLOPHON
This page is part of release 5.10 of the Linux
.I man-pages
project.
A description of the project,
information about reporting bugs,
and the latest version of this page,
can be found at
\%https://www.kernel.org/doc/man\-pages/.
|
