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ILOGB(3) | Linux Programmer's Manual | ILOGB(3) |
NAME¶
ilogb, ilogbf, ilogbl - get integer exponent of a floating-point valueSYNOPSIS¶
#include <math.h>Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
_BSD_SOURCE || _SVID_SOURCE ||
_XOPEN_SOURCE >= 500 ||
_XOPEN_SOURCE && _XOPEN_SOURCE_EXTENDED || _ISOC99_SOURCE ||
_POSIX_C_SOURCE >= 200112L;
or cc -std=c99
_BSD_SOURCE || _SVID_SOURCE ||
_XOPEN_SOURCE >= 600 || _ISOC99_SOURCE ||
_POSIX_C_SOURCE >= 200112L;
or cc -std=c99
DESCRIPTION¶
These functions return the exponent part of their argument as a signed integer. When no error occurs, these functions are equivalent to the corresponding logb(3) functions, cast to int.RETURN VALUE¶
On success, these functions return the exponent of x, as a signed integer.ERRORS¶
See math_error(7) for information on how to determine whether an error has occurred when calling these functions. The following errors can occur:- Domain error: x is 0 or a NaN
- An invalid floating-point exception (FE_INVALID) is raised.
- These functions do not set errno for this case.
- Domain error: x is an infinity
- These functions do not set errno or raise an exception for this case.
CONFORMING TO¶
C99, POSIX.1-2001.SEE ALSO¶
log(3), logb(3), significand(3)COLOPHON¶
This page is part of release 3.44 of the Linux man-pages project. A description of the project, and information about reporting bugs, can be found at http://www.kernel.org/doc/man-pages/.2010-09-20 |