C standard library errno.h

The errno.h header file of the C Standard Library defines the integer variable errno, which is set by system calls and some library functions in the event of an error to indicate what went wrong.

Library Macros

extern int errno

This is the macro set by system calls and some library functions in the event of an error to indicate what went wrong.

EDOM Domain Error

This macro represents a domain error, which occurs if an input argument is outside the domain, over which the mathematical function is defined and errno is set to EDOM.

ERANGE Range Error

This macro represents a range error, which occurs if an input argument is outside the range, over which the mathematical function is defined and errno is set to ERANGE.

C Library - <float.h>

The float.h header file of the C Standard Library contains a set of various platform-dependent constants related to floating point values. These constants are proposed by ANSI C.

C Library - <limits.h>

The limits.h header determines various properties of the various variable types. The macros defined in this header, limits the values of various variable types like char, int and long.

C Library - <math.h>

The math.h header defines various mathematical functions and one macro. All the functions available in this library take double as an argument and return double as the result.

Library Functions

double acos(double x)

Returns the arc cosine of x in radians.

double asin(double x)

Returns the arc sine of x in radians.

double atan(double x)

Returns the arc tangent of x in radians.

double atan2(doubly y, double x)

Returns the arc tangent in radians of y/x based on the signs of both values to determine the correct quadrant.

double cos(double x)

Returns the cosine of a radian angle x.

double cosh(double x)

Returns the hyperbolic cosine of x.

double sin(double x)

Returns the sine of a radian angle x.

double tanh(double x)

Returns the hyperbolic tangent of x.

double exp(double x)

Returns the value of e raised to the xth power.

double frexp(double x, int *exponent)

The returned value is the mantissa and the integer pointed to by exponent is the exponent. The resultant value is x = mantissa * 2 ^ exponent.

double ldexp(double x, int exponent)

Returns x multiplied by 2 raised to the power of exponent.

double log(double x)

Returns the natural logarithm (base-e logarithm) of x.

double log10(double x)

Returns the common logarithm (base-10 logarithm) of x.

double modf(double x, double *integer)

The returned value is the fraction component (part after the decimal), and sets integer to the integer component.

double pow(double x, double y)

Returns x raised to the power of y.

double sqrt(double x)

Returns the square root of x.

double ceil(double x)

Returns the smallest integer value greater than or equal to x.

double fabs(double x)

Returns the absolute value of x.

double floor(double x)

Returns the largest integer value less than or equal to x.

double fmod(double x, double y)

Returns the remainder of x divided by y.

C Library - <setjmp.h>

The setjmp.h header defines the macro setjmp(), one function longjmp(), and one variable type jmp_buf, for bypassing the normal function call and return discipline.