Usage type specifier for the character types (char, signed char, and unsigned char).

Defined in header <math.h> float acosf( float arg ); (1) (since C99) double acos( double arg ); (2) long double acosl( long double arg ); (3) (since C99) Defined in header <tgmath.h> #define acos( arg ) (4) (since C99) 1-3) Computes the principal value of the arc cosine of arg. 4) Type-generic macro: If the argument has type long double, acosl is called. Otherwise, if the argument has integer type or the type double, acos is calle

Defined in header <threads.h> int tss_create( tss_t* tss_key, tss_dtor_t destructor ); (since C11) Creates new thread-specific storage key and stores it in the object pointed to by tss_key. Although the same key value may be used by different threads, the values bound to the key by tss_set are maintained on a per-thread basis and persist for the life of the calling thread. The value NULL is associated with the newly created key in all existing threads, and upon thread creat

Usage if statement: as the declaration of the if statement

Defined in header <ctype.h> int isspace( int ch ); Checks if the given character is a whitespace character, i.e. either space (0x20), form feed (0x0c), line feed (0x0a), carriage return (0x0d), horizontal tab (0x09) or vertical tab (0x0b). The behavior is undefined if the value of ch is not representable as unsigned char and is not equal to EOF. Parameters ch - character to classify Return value Non-zero value if the character is a whitespace character, zero o

Defined in header <wctype.h> int iswxdigit( wint_t ch ); (since C95) Checks if the given wide character corresponds (if narrowed) to a hexadecimal numeric character, i.e. one of 0123456789abcdefABCDEF. Parameters ch - wide character Return value Non-zero value if the wide character is a hexadecimal numeric character, zero otherwise. Notes iswdigit and iswxdigit are the only standard wide character classification functions that are not affected by the curren

Usage thread storage-class specifier.

Declares a member with explicit width, in bits. Adjacent bit field members may be packed to share and straddle the individual bytes. A bit field declaration is a struct or union member declaration which uses the following declarator: identifier(optional) : width identifier - the name of the bit field that is being declared. The name is optional: nameless bitfields introduce the specified number of bits of padding width - an integer constant expression with a value greater or

Defined in header <string.h> (1) char *strncpy( char *dest, const char *src, size_t count ); (until C99) char *strncpy( char *restrict dest, const char *restrict src, size_t count ); (since C99) errno_t strncpy_s(char *restrict dest, rsize_t destsz, const char *restrict src, rsize_t count); (2) (since C11) 1) Copies at most count characters of the character array pointed to by src (including the terminating null character, but not any of the c

Defined in header <stdlib.h> #define RAND_MAX /*implementation defined*/ Expands to an integer constant expression equal to the maximum value returned by the function rand(). This value is implementation dependent. It's guaranteed that this value is at least 32767. References C11 standard (ISO/IEC 9899:2011): 7.22/3 General utilities <stdlib.h> (p: 340) C99 standard (ISO/IEC 9899:1999): 7.20/3 General utilities <stdlib.h> (p: 306) C89/C90 standard (ISO