| .\" Copyright 1993 David Metcalfe (david@prism.demon.co.uk) |
| .\" and Copyright 2008, Linux Foundation, written by Michael Kerrisk |
| .\" <mtk.manpages@gmail.com> |
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| .\" manual under the conditions for verbatim copying, provided that the |
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| .\" Since the Linux kernel and libraries are constantly changing, this |
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| .\" References consulted: |
| .\" Linux libc source code |
| .\" Lewine's _POSIX Programmer's Guide_ (O'Reilly & Associates, 1991) |
| .\" 386BSD man pages |
| .\" Modified 1993-07-24 by Rik Faith (faith@cs.unc.edu) |
| .\" Modified 2002-07-27 by Walter Harms |
| .\" (walter.harms@informatik.uni-oldenburg.de) |
| .\" |
| .TH FMOD 3 2016-03-15 "" "Linux Programmer's Manual" |
| .SH NAME |
| fmod, fmodf, fmodl \- floating-point remainder function |
| .SH SYNOPSIS |
| .nf |
| .B #include <math.h> |
| .sp |
| .BI "double fmod(double " x ", double " y ); |
| .br |
| .BI "float fmodf(float " x ", float " y ); |
| .br |
| .BI "long double fmodl(long double " x ", long double " y ); |
| .fi |
| .sp |
| Link with \fI\-lm\fP. |
| .sp |
| .in -4n |
| Feature Test Macro Requirements for glibc (see |
| .BR feature_test_macros (7)): |
| .in |
| .sp |
| .ad l |
| .BR fmodf (), |
| .BR fmodl (): |
| .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 compute the floating-point remainder of dividing |
| .I x |
| by |
| .IR y . |
| The return value is |
| .IR x |
| \- |
| .I n |
| * |
| .IR y , |
| where |
| .I n |
| is the quotient of |
| .I x |
| / |
| .IR y , |
| rounded toward zero to an integer. |
| .SH RETURN VALUE |
| On success, these |
| functions return the value \fIx\fP\ \-\ \fIn\fP*\fIy\fP, |
| for some integer |
| .IR n , |
| such that the returned value has the same sign as |
| .I x |
| and a magnitude less than the magnitude of |
| .IR y . |
| |
| If |
| .I x |
| or |
| .I y |
| is a NaN, a NaN is returned. |
| |
| If |
| .I x |
| is an infinity, |
| a domain error occurs, and |
| a NaN is returned. |
| |
| If |
| .I y |
| is zero, |
| a domain error occurs, and |
| a NaN is returned. |
| |
| If |
| .I x |
| is +0 (\-0), and |
| .I y |
| is not zero, +0 (\-0) is returned. |
| .SH ERRORS |
| See |
| .BR math_error (7) |
| for information on how to determine whether an error has occurred |
| when calling these functions. |
| .PP |
| The following errors can occur: |
| .TP |
| Domain error: \fIx\fP is an infinity |
| .I errno |
| is set to |
| .BR EDOM |
| (but see BUGS). |
| An invalid floating-point exception |
| .RB ( FE_INVALID ) |
| is raised. |
| .TP |
| Domain error: \fIy\fP is zero |
| .I errno |
| is set to |
| .BR EDOM . |
| An invalid floating-point exception |
| .RB ( FE_INVALID ) |
| is raised. |
| .\" POSIX.1 documents an optional underflow error, but AFAICT it doesn't |
| .\" (can't?) occur -- mtk, Jul 2008 |
| .SH ATTRIBUTES |
| For an explanation of the terms used in this section, see |
| .BR attributes (7). |
| .TS |
| allbox; |
| lbw24 lb lb |
| l l l. |
| Interface Attribute Value |
| T{ |
| .BR fmod (), |
| .BR fmodf (), |
| .BR fmodl () |
| T} Thread safety MT-Safe |
| .TE |
| .SH CONFORMING TO |
| C99, POSIX.1-2001, POSIX.1-2008. |
| |
| The variant returning |
| .I double |
| also conforms to |
| SVr4, 4.3BSD, C89. |
| .SH BUGS |
| Before version 2.10, the glibc implementation did not set |
| .\" http://sources.redhat.com/bugzilla/show_bug.cgi?id=6784 |
| .I errno |
| to |
| .B EDOM |
| when a domain error occurred for an infinite |
| .IR x . |
| .SH SEE ALSO |
| .BR remainder (3) |