logbl(3) [freebsd man page]

ILOGB(3)						   BSD Library Functions Manual 						  ILOGB(3)

NAME

     ilogb, ilogbf, ilogbl, logb, logbf, logbl -- extract exponent

LIBRARY

     Math Library (libm, -lm)

SYNOPSIS

     #include <math.h>

     int
     ilogb(double x);

     int
     ilogbf(float x);

     int
     ilogbl(long double x);

     double
     logb(double x);

     float
     logbf(float x);

     long double
     logbl(long double x);

DESCRIPTION

     ilogb(), ilogbf() and ilogbl() return x's exponent in integer format.  ilogb(+-infinity) returns INT_MAX, ilogb(+-NaN) returns FP_ILOGBNAN,
     and ilogb(0) returns FP_ILOGB0.

     logb(x), logbf(x), and logbl(x) return x's exponent in floating-point format with the same precision as x.  logb(+-infinity) returns +infin-
     ity, and logb(0) returns -infinity with a division by zero exception.

SEE ALSO

     frexp(3), ieee(3), math(3), scalbn(3)

STANDARDS

     The ilogb(), ilogbf(), ilogbl(), logb(), logbf(), and logbl() routines conform to ISO/IEC 9899:1999 (``ISO C99'').  The latter three imple-
     ment the logb function recommended by IEEE Std 754-1985.

HISTORY

     Function	First Appeared In
     logb()	4.3BSD
     ilogb()	FreeBSD 1.1.5
     ilogbf()	FreeBSD 2.0
     logbf()	FreeBSD 2.0
     ilogbl()	FreeBSD 5.4
     logbl()	FreeBSD 8.0

BSD
								 December 16, 2007							       BSD

ILOGB(3)						   BSD Library Functions Manual 						  ILOGB(3)

NAME

     ilogb, ilogbf, ilogbl, logb, logbf, logbl -- extract exponent

LIBRARY

     Math Library (libm, -lm)

SYNOPSIS

     #include <math.h>

     int
     ilogb(double x);

     int
     ilogbf(float x);

     int
     ilogbl(long double x);

     double
     logb(double x);

     float
     logbf(float x);

     long double
     logbl(long double x);

DESCRIPTION

     ilogb(), ilogbf() and ilogbl() return x's exponent in integer format.  ilogb(+-infinity) returns INT_MAX, ilogb(+-NaN) returns FP_ILOGBNAN,
     and ilogb(0) returns FP_ILOGB0.

     logb(x), logbf(x), and logbl(x) return x's exponent in floating-point format with the same precision as x.  logb(+-infinity) returns +infin-
     ity, and logb(0) returns -infinity with a division by zero exception.

SEE ALSO

     frexp(3), ieee(3), math(3), scalbn(3)

STANDARDS

     The ilogb(), ilogbf(), ilogbl(), logb(), logbf(), and logbl() routines conform to ISO/IEC 9899:1999 (``ISO C99'').  The latter three imple-
     ment the logb function recommended by IEEE Std 754-1985.

HISTORY

     Function	First Appeared In
     logb()	4.3BSD
     ilogb()	FreeBSD 1.1.5
     ilogbf()	FreeBSD 2.0
     logbf()	FreeBSD 2.0
     ilogbl()	FreeBSD 5.4
     logbl()	FreeBSD 8.0

BSD
								 December 16, 2007							       BSD