|ILOGB(3)||Linux Programmer's Manual||ILOGB(3)|
NAMEilogb, ilogbf, ilogbl - get integer exponent of a floating-point value
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
DESCRIPTIONThese 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 VALUEOn success, these functions return the exponent of x, as a signed integer.
ERRORSSee 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 TOC99, POSIX.1-2001.
SEE ALSOlog(3), logb(3), significand(3)
COLOPHONThis page is part of release 3.53 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/.