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

20       The functionality described on this reference page is aligned with  the
21       ISO C  standard.  Any  conflict between the requirements described here
22       and the ISO C standard is unintentional. This  volume  of  POSIX.1‐2017
23       defers to the ISO C standard.
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25       The  isfinite() macro shall determine whether its argument has a finite
26       value (zero, subnormal, or normal, and not infinite or NaN). First,  an
27       argument  represented  in a format wider than its semantic type is con‐
28       verted to its semantic type. Then determination is based on the type of
29       the argument.
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RETURN VALUE

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

36       No errors are defined.
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38       The following sections are informative.
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EXAMPLES

41       None.
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APPLICATION USAGE

44       None.
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RATIONALE

47       None.
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FUTURE DIRECTIONS

50       None.
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SEE ALSO

53       fpclassify(), isinf(), isnan(), isnormal(), signbit()
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55       The Base Definitions volume of POSIX.1‐2017, <math.h>
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58       Portions of this text are reprinted and reproduced in  electronic  form
59       from  IEEE Std 1003.1-2017, Standard for Information Technology -- Por‐
60       table Operating System Interface (POSIX), The Open Group Base  Specifi‐
61       cations  Issue  7, 2018 Edition, Copyright (C) 2018 by the Institute of
62       Electrical and Electronics Engineers, Inc and The Open Group.   In  the
63       event of any discrepancy between this version and the original IEEE and
64       The Open Group Standard, the original IEEE and The Open Group  Standard
65       is  the  referee document. The original Standard can be obtained online
66       at http://www.opengroup.org/unix/online.html .
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68       Any typographical or formatting errors that appear  in  this  page  are
69       most likely to have been introduced during the conversion of the source
70       files to man page format. To report such errors,  see  https://www.ker‐
71       nel.org/doc/man-pages/reporting_bugs.html .
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75IEEE/The Open Group                  2017                         ISFINITE(3P)
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