frexp(3p) — Linux manual page

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

PROLOG         top

       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         top

       frexp, frexpf, frexpl — extract mantissa and exponent from a
       double precision number

SYNOPSIS         top

       #include <math.h>

       double frexp(double num, int *exp);
       float frexpf(float num, int *exp);
       long double frexpl(long double num, int *exp);

DESCRIPTION         top

       The functionality described on this reference page is aligned with
       the ISO C standard. Any conflict between the requirements
       described here and the ISO C standard is unintentional. This
       volume of POSIX.1‐2017 defers to the ISO C standard.

       These functions shall break a floating-point number num into a
       normalized fraction and an integral power of 2. The integer
       exponent shall be stored in the int object pointed to by exp.

RETURN VALUE         top

       For finite arguments, these functions shall return the value x,
       such that x has a magnitude in the interval [½,1) or 0, and num
       equals x times 2 raised to the power *exp.

       If num is NaN, a NaN shall be returned, and the value of *exp is
       unspecified.

       If num is ±0, ±0 shall be returned, and the value of *exp shall be
       0.

       If num is ±Inf, num shall be returned, and the value of *exp is
       unspecified.

ERRORS         top

       No errors are defined.

       The following sections are informative.

EXAMPLES         top

       None.

APPLICATION USAGE         top

       None.

RATIONALE         top

       None.

FUTURE DIRECTIONS         top

       None.

SEE ALSO         top

       isnan(3p), ldexp(3p), modf(3p)

       The Base Definitions volume of POSIX.1‐2017, math.h(0p)

COPYRIGHT         top

       Portions of this text are reprinted and reproduced in electronic
       form from IEEE Std 1003.1-2017, Standard for Information
       Technology -- Portable Operating System Interface (POSIX), The
       Open Group Base Specifications Issue 7, 2018 Edition, Copyright
       (C) 2018 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 .

       Any typographical or formatting errors that appear in this page
       are most likely to have been introduced during the conversion of
       the source files to man page format. To report such errors, see
       https://www.kernel.org/doc/man-pages/reporting_bugs.html .

IEEE/The Open Group                2017                         FREXP(3P)

Pages that refer to this page: math.h(0p),  ldexp(3p),  modf(3p)

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