1ISFINITE(3P)               POSIX Programmer's Manual              ISFINITE(3P)
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PROLOG

6       This  manual  page is part of the POSIX Programmer's Manual.  The Linux
7       implementation of this interface may differ (consult the  corresponding
8       Linux  manual page for details of Linux behavior), or the interface may
9       not be implemented on Linux.
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NAME

12       isfinite - test for finite value
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SYNOPSIS

15       #include <math.h>
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17       int isfinite(real-floating x);
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DESCRIPTION

21       The isfinite() macro shall determine whether its argument has a  finite
22       value  (zero, subnormal, or normal, and not infinite or NaN). First, an
23       argument represented in a format wider than its semantic type  is  con‐
24       verted to its semantic type. Then determination is based on the type of
25       the argument.
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RETURN VALUE

28       The isfinite() macro shall return a non-zero value if and only  if  its
29       argument has a finite value.
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ERRORS

32       No errors are defined.
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34       The following sections are informative.
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EXAMPLES

37       None.
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APPLICATION USAGE

40       None.
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RATIONALE

43       None.
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FUTURE DIRECTIONS

46       None.
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SEE ALSO

49       fpclassify(), isinf(), isnan(), isnormal(), signbit(), the Base Defini‐
50       tions volume of IEEE Std 1003.1-2001 <math.h>
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53       Portions of this text are reprinted and reproduced in  electronic  form
54       from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
55       -- Portable Operating System Interface (POSIX),  The  Open  Group  Base
56       Specifications  Issue  6,  Copyright  (C) 2001-2003 by the Institute of
57       Electrical and Electronics Engineers, Inc and The Open  Group.  In  the
58       event of any discrepancy between this version and the original IEEE and
59       The Open Group Standard, the original IEEE and The Open Group  Standard
60       is  the  referee document. The original Standard can be obtained online
61       at http://www.opengroup.org/unix/online.html .
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65IEEE/The Open Group                  2003                         ISFINITE(3P)
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