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

13       isfinite — test for finite value
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SYNOPSIS

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

21       The functionality described on this reference page is aligned with  the
22       ISO C  standard.  Any  conflict between the requirements described here
23       and the ISO C standard is unintentional. This  volume  of  POSIX.1‐2008
24       defers to the ISO C standard.
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26       The  isfinite() macro shall determine whether its argument has a finite
27       value (zero, subnormal, or normal, and not infinite or NaN). First,  an
28       argument  represented  in a format wider than its semantic type is con‐
29       verted to its semantic type. Then determination is based on the type of
30       the argument.
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RETURN VALUE

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

37       No errors are defined.
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39       The following sections are informative.
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EXAMPLES

42       None.
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APPLICATION USAGE

45       None.
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RATIONALE

48       None.
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FUTURE DIRECTIONS

51       None.
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SEE ALSO

54       fpclassify(), isinf(), isnan(), isnormal(), signbit()
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56       The Base Definitions volume of POSIX.1‐2008, <math.h>
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59       Portions of this text are reprinted and reproduced in  electronic  form
60       from IEEE Std 1003.1, 2013 Edition, Standard for Information Technology
61       -- Portable Operating System Interface (POSIX),  The  Open  Group  Base
62       Specifications Issue 7, Copyright (C) 2013 by the Institute of Electri‐
63       cal and Electronics Engineers,  Inc  and  The  Open  Group.   (This  is
64       POSIX.1-2008  with  the  2013  Technical Corrigendum 1 applied.) In the
65       event of any discrepancy between this version and the original IEEE and
66       The  Open Group Standard, the original IEEE and The Open Group Standard
67       is the referee document. The original Standard can be  obtained  online
68       at http://www.unix.org/online.html .
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70       Any  typographical  or  formatting  errors that appear in this page are
71       most likely to have been introduced during the conversion of the source
72       files  to  man page format. To report such errors, see https://www.ker‐
73       nel.org/doc/man-pages/reporting_bugs.html .
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77IEEE/The Open Group                  2013                         ISFINITE(3P)
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