fanotify_init.2, fanotify.7: Document FAN_REPORT_TID

[thirdparty/man-pages.git] / man3 / floor.3

diff --git a/man3/floor.3 b/man3/floor.3
index 9b9fefac2edc389e9ab58e4e86337722c1be8225..6c6ff3d87f6e2dcc858d32c33a434407fc3794ec 100644 (file)
--- a/man3/floor.3
+++ b/man3/floor.3
@@ -1,5 +1,8 @@
 .\" Copyright 2001 Andries Brouwer <aeb@cwi.nl>.
+.\" and Copyright 2008, Linux Foundation, written by Michael Kerrisk
+.\"     <mtk.manpages@gmail.com>
 .\"
+.\" %%%LICENSE_START(VERBATIM)
 .\" Permission is granted to make and distribute verbatim copies of this
 .\" manual provided the copyright notice and this permission notice are
 .\" preserved on all copies.
@@ -19,50 +22,95 @@
 .\"
 .\" Formatted or processed versions of this manual, if unaccompanied by
 .\" the source, must acknowledge the copyright and authors of this work.
+.\" %%%LICENSE_END
 .\"
-.TH FLOOR 3  2001-05-31 "" "Linux Programmer's Manual"
+.TH FLOOR 3  2017-09-15 "" "Linux Programmer's Manual"
 .SH NAME
 floor, floorf, floorl \- largest integral value not greater than argument
 .SH SYNOPSIS
 .nf
 .B #include <math.h>
-.sp
+.PP
 .BI "double floor(double " x );
-.br
 .BI "float floorf(float " x );
-.br
 .BI "long double floorl(long double " x );
 .fi
-.sp
-Link with \-lm.
+.PP
+Link with \fI\-lm\fP.
+.PP
+.in -4n
+Feature Test Macro Requirements for glibc (see
+.BR feature_test_macros (7)):
+.in
+.PP
+.ad l
+.BR floorf (),
+.BR floorl ():
+.RS 4
+_ISOC99_SOURCE || _POSIX_C_SOURCE\ >=\ 200112L
+    || /* Since glibc 2.19: */ _DEFAULT_SOURCE
+    || /* Glibc versions <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE
+.RE
+.ad
 .SH DESCRIPTION
-These functions round \fIx\fP down to the nearest integer.
-.SH "RETURN VALUE"
-The rounded integer value.
-If \fIx\fP is integral or infinite,
-\fIx\fP itself is returned.
+These functions return the largest integral value that is not greater than
+.IR x .
+.PP
+For example,
+.IR floor(0.5)
+is 0.0, and
+.IR floor(\-0.5)
+is \-1.0.
+.SH RETURN VALUE
+These functions return the floor of
+.IR x .
+.PP
+If
+.I x
+is integral, +0, \-0, NaN, or an infinity,
+.I x
+itself is returned.
 .SH ERRORS
-No errors other than EDOM and ERANGE can occur.
-If \fIx\fP is NaN, then NaN is returned and
-.I errno
-may be set to EDOM.
+No errors occur.
+POSIX.1-2001 documents a range error for overflows, but see NOTES.
+.SH ATTRIBUTES
+For an explanation of the terms used in this section, see
+.BR attributes (7).
+.TS
+allbox;
+lbw27 lb lb
+l l l.
+Interface      Attribute       Value
+T{
+.BR floor (),
+.BR floorf (),
+.BR floorl ()
+T}     Thread safety   MT-Safe
+.TE
+.SH CONFORMING TO
+C99, POSIX.1-2001, POSIX.1-2008.
+.PP
+The variant returning
+.I double
+also conforms to
+SVr4, 4.3BSD, C89.
 .SH NOTES
 SUSv2 and POSIX.1-2001 contain text about overflow (which might set
 .I errno
-to ERANGE, or raise an exception).
+to
+.BR ERANGE ,
+or raise an
+.B FE_OVERFLOW
+exception).
 In practice, the result cannot overflow on any current machine,
 so this error-handling stuff is just nonsense.
+.\" The POSIX.1-2001 APPLICATION USAGE SECTION discusses this point.
 (More precisely, overflow can happen only when the maximum value
 of the exponent is smaller than the number of mantissa bits.
-For the IEEE-754 standard 32-bit and 64-bit floating point numbers
-the maximum value of the exponent is 128 (resp. 1024), and the number
-of mantissa bits is 24 (resp. 53).)
-.SH "CONFORMING TO"
-The
-.BR floor ()
-function conforms to SVr4, 4.3BSD, C89.
-The other functions are from C99.
-.SH "SEE ALSO"
+For the IEEE-754 standard 32-bit and 64-bit floating-point numbers
+the maximum value of the exponent is 128 (respectively, 1024),
+and the number of mantissa bits is 24 (respectively, 53).)
+.SH SEE ALSO
 .BR ceil (3),
 .BR lrint (3),
 .BR nearbyint (3),