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ISINF(3P)                  POSIX Programmer's Manual                 ISINF(3P)

PROLOG
       This  manual  page is part of the POSIX Programmer's Manual.  The Linux
       implementation of this interface may differ (consult the  corresponding
       Linux  manual page for details of Linux behavior), or the interface may
       not be implemented on Linux.
NAME
       isinf - test for infinity
SYNOPSIS
       #include <math.h>
       int isinf(real-floating x);

DESCRIPTION
       The isinf() macro shall determine whether  its  argument  value  is  an
       infinity  (positive  or  negative). First, an argument represented in a
       format wider than its semantic type is converted to its semantic  type.
       Then determination is based on the type of the argument.
RETURN VALUE
       The  isinf()  macro  shall  return  a non-zero value if and only if its
       argument has an infinite value.
ERRORS
       No errors are defined.
       The following sections are informative.
EXAMPLES
       None.
APPLICATION USAGE
       None.
RATIONALE
       None.
FUTURE DIRECTIONS
       None.
SEE ALSO
       fpclassify(), isfinite(), isnan(), isnormal(), signbit(), the Base Def-
       initions volume of IEEE Std 1003.1-2001 <math.h>
COPYRIGHT
       Portions  of  this text are reprinted and reproduced in electronic form
       from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
       --  Portable  Operating  System  Interface (POSIX), The Open Group Base
       Specifications Issue 6, Copyright (C) 2001-2003  by  the  Institute  of
       Electrical  and  Electronics  Engineers, Inc and The Open Group. In the
       event of any discrepancy between this version and the original IEEE and
       The  Open Group Standard, the original IEEE and The Open Group Standard
       is the referee document. The original Standard can be  obtained  online
       at http://www.opengroup.org/unix/online.html .

IEEE/The Open Group                  2003                            ISINF(3P)