Defined in header <stdio.h> int fclose( FILE *stream ); Closes the given file stream. Any unwritten buffered data are flushed to the OS. Any unread buffered data are discarded. Whether or not the operation succeeds, the stream is no longer associated with a file, and the buffer allocated by setbuf or setvbuf, if any, is also disassociated and deallocated if automatic allocation was used. Parameters stream - the file stream to close Return value ​0​ on success,

Defined in header <math.h> float fabsf( float arg ); (1) (since C99) double fabs( double arg ); (2) long double fabsl( long double arg ); (3) (since C99) Defined in header <tgmath.h> #define fabs( arg ) (4) (since C99) 1-3) Computes the absolute value of a floating point value arg. 4) Type-generic macro: If the argument has type long double, fabsl is called. Otherwise, if the argument has integer type or has type double, fabs is c

At the top level of a translation unit (that is, a source file with all the #includes after the preprocessor), every C program is a sequence of declarations, which declare functions and objects with external linkage. These declarations are known as external declarations because they appear outside of any function. extern int n; // external declaration with external linkage int b = 1; // external definition with external linkage static const char *c = "abc"; // external definition with intern

Usage static duration storage-class specifier with either internal or more usually external linkage.

An expression is a sequence of operators and their operands, that specifies a computation. Expression evaluation may produce a result (e.g., evaluation of 2+2 produces the result 4), may generate side-effects (e.g. evaluation of printf("%d",4) sends the character '4' to the standard output stream), and may designate objects or functions. General value categories (lvalue, non-lvalue, function designator) classify expressions by their values order of evaluation of arguments and subexpressio

Defined in header <math.h> float expm1f( float arg ); (1) (since C99) double expm1( double arg ); (2) (since C99) long double expm1l( long double arg ); (3) (since C99) Defined in header <tgmath.h> #define expm1( arg ) (4) (since C99) 1-3) Computes the e (Euler's number, 2.7182818) raised to the given power arg, minus 1.0. This function is more accurate than the expression std::exp(arg)-1.0 if arg is close to zero. 4) Type-generic

Defined in header <math.h> float exp2f( float n ); (1) (since C99) double exp2( double n ); (2) (since C99) long double exp2l( long double n ); (3) (since C99) Defined in header <tgmath.h> #define exp2( n ) (4) (since C99) 1-3) Computes 2 raised to the given power n. 4) Type-generic macro: If n has type long double, exp2l is called. Otherwise, if n has integer type or the type double, exp2 is called. Otherwise, exp2f is called.

Defined in header <math.h> float expf( float arg ); (1) (since C99) double exp( double arg ); (2) long double expl( long double arg ); (3) (since C99) Defined in header <tgmath.h> #define exp( arg ) (4) (since C99) 1-3) Computes the e (Euler's number, 2.7182818) raised to the given power arg. 4) Type-generic macro: If arg has type long double, expl is called. Otherwise, if arg has integer type or the type double, exp is called. Ot

Defined in header <stdlib.h> #define EXIT_SUCCESS /*implementation defined*/ #define EXIT_FAILURE /*implementation defined*/ The EXIT_SUCCESS and EXIT_FAILURE macros expand into integral expressions that can be used as arguments to the exit function (and, therefore, as the values to return from the main function), and indicate program execution status. Constant Explanation EXIT_SUCCESS successful execution of a program EXIT_FAILURE unsuccessful execution of

Defined in header <stdlib.h> void exit( int exit_code ); (until C11) _Noreturn void exit( int exit_code ); (since C11) Causes normal program termination to occur. Several cleanup steps are performed: functions passed to atexit are called, in reverse order of registration all C streams are flushed and closed files created by tmpfile are removed control is returned to the host environment. If exit_code is zero or EXIT_SUCCESS, an implementation-defined status, in