Defined in header <stdlib.h> int mblen( const char* s, size_t n ); Determines the size, in bytes, of the multibyte character whose first byte is pointed to by s. If s is a null pointer, resets the global conversion state and determined whether shift sequences are used. This function is equivalent to the call mbtowc((wchar_t*)0, s, n), except that conversion state of mbtowc is unaffected. Notes Each call to mblen updates the internal global conversion state (a static obje

Defined in header <ctype.h> int isgraph( int ch ); Checks if the given character has a graphical representation, i.e. it is either a number (0123456789), an uppercase letter (ABCDEFGHIJKLMNOPQRSTUVWXYZ), a lowercase letter (abcdefghijklmnopqrstuvwxyz), or a punctuation character(!"#$%&'()*+,-./:;<=>?@[\]^_`{|}~), or any graphical character specific to the current C locale. The behavior is undefined if the value of ch is not representable as unsigned char and is no

Defined in header <complex.h> float cprojf( float complex z ); (1) (since C99) double cproj( double complex z ); (2) (since C99) long double cprojl( long double complex z ); (3) (since C99) Defined in header <tgmath.h> #define cproj( z ) (4) (since C99) 1-3) Computes the projection of z on the Riemann sphere. 4) Type-generic macro: if z has type long double complex, long double imaginary, or long double, cprojl is called. If z has

Defined in header <stdlib.h> void free( void* ptr ); Deallocates the space previously allocated by malloc(), calloc(), aligned_alloc, (since C11) or realloc(). If ptr is a null pointer, the function does nothing. The behavior is undefined if the value of ptr does not equal a value returned earlier by malloc(), calloc(), realloc(), or aligned_alloc() (since C11). The behavior is undefined if the memory area referred to by ptr has already been deallocated, that is, free() or

Usage continue statement: as the declaration of the statement

Defined in header <uchar.h> size_t mbrtoc16( char16_t* pc16, const char* s, size_t n, mbstate_t* ps ); (since C11) Converts a narrow multibyte character to 16-bit character representation (typically, UTF-16). If s is not a null pointer, inspects at most n bytes of the multibyte character string, beginning with the byte pointed to by s to determine the number of bytes necessary to complete the next multibyte character (including any shift sequences). If the function determin

Defined in header <locale.h> char* setlocale( int category, const char* locale); The setlocale function installs the specified system locale or its portion as the new C locale. The modifications remain in effect and influences the execution of all locale-sensitive C library functions until the next call to setlocale. If locale is a null pointer, setlocale queries the current C locale without modifying it. Parameters category - locale category identifier, one of the

Implementation defined behavior is controlled by #pragma directive. Syntax #pragma pragma_params (1) _Pragma ( string-literal ) (2) (since C99) 1) Behaves in an implementation-defined manner (unless pragma_params is one of the standard pragmas shown below. 2) Removes the encoding prefix (if any), the outer quotes, and leading/trailing whitespace from string-literal, replaces each \" with " and each \\ with \, then tokenizes the result (as in translation stage 3), and then use

A null-terminated byte string (NTBS) is a sequence of nonzero bytes followed by a byte with value zero (the terminating null character). Each byte in a byte string encodes one character of some character set. For example, the character array {'\x63','\x61','\x74','\0'} is an NTBS holding the string "cat" in ASCII encoding. Functions Character classification Defined in header <ctype.h> isalnum checks if a character is alphanumeric (function) isalpha checks if a charact

Defined in header <wchar.h> int wcscoll( const wchar_t *lhs, const wchar_t *rhs ); (since C95) Compares two null-terminated wide strings according to the collation order defined by the LC_COLLATE category of the currently installed locale. Parameters lhs, rhs - pointers to the null-terminated wide strings to compare Return value Negative value if lhs is less than (precedes) rhs. ​0​ if lhs is equal to rhs. Positive value if lhs is greater than (follows) rhs.