floor(3p) — Linux manual page

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

       floor, floorf, floorl — floor function

SYNOPSIS

       #include <math.h>

       double floor(double x);
       float floorf(float x);
       long double floorl(long double x);

DESCRIPTION

       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 compute the largest integral value not
       greater than x.

RETURN VALUE

       The result shall have the same sign as x.

       Upon successful completion, these functions shall return the
       largest integral value not greater than x, expressed as a double,
       float, or long double, as appropriate for the return type of the
       function.

       If x is NaN, a NaN shall be returned.

       If x is ±0 or ±Inf, x shall be returned.

ERRORS

       No errors are defined.

       The following sections are informative.

EXAMPLES

       None.

APPLICATION USAGE

       The integral value returned by these functions might not be
       expressible as an intmax_t.  The return value should be tested
       before assigning it to an integer type to avoid the undefined
       results of an integer overflow.

       These functions may raise the inexact floating-point exception if
       the result differs in value from the argument.

RATIONALE

       None.

FUTURE DIRECTIONS

       None.

SEE ALSO

       ceil(3p), feclearexcept(3p), fetestexcept(3p), isnan(3p)

       Section 4.20, Treatment of Error Conditions for Mathematical
       Functions, math.h(0p)

COPYRIGHT

       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                         FLOOR(3P)

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

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