Defined in header <signal.h> #define SIG_DFL /*implementation defined*/ #define SIG_IGN /*implementation defined*/ The SIG_DFL and SIG_IGN macros expand into integral expressions that are not equal to an address of any function. The macros define signal handling strategies for signal() function. Constant Explanation SIG_DFL default signal handling SIG_IGN signal is ignored Example #include <signal.h> #include <stdio.h> int main(void) {

Defined in header <wchar.h> wint_t fgetwc( FILE *stream ); (since C95) wint_t getwc( FILE *stream ); (since C95) Reads the next wide character from the given input stream. getwc() may be implemented as a macro and may evaluate stream more than once. Parameters stream - to read the wide character from Return value The next wide character from the stream or WEOF if an error has occurred or the end of file has been reached. If an encoding error occurred, er

Defined in header <stdio.h> int rename( const char *old_filename, const char *new_filename ); Changes the filename of a file. The file is identified by character string pointed to by old_filename. The new filename is identified by character string pointed to by new_filename. If new_filename exists, the behavior is implementation-defined. Parameters old_filename - pointer to a null-terminated string containing the path identifying the file to rename new_filename

Defined in header <time.h> char* ctime( const time_t* time ); (1) errno_t ctime_s(char *buffer, rsize_t bufsz, const time_t *time); (2) (since C11) 1) Converts given time since epoch to a calendar local time and then to a textual representation, as if by calling asctime(localtime(time)). 2) Same as (1), except that the function is equivalent to asctime_s(buffer, bufsz, localtime_s(time, &(struct tm){0})), and the following errors are detected at runtime and call

Defined in header <stdlib.h> void _Exit( int exit_code ); (since C99) Causes normal program termination to occur without completely cleaning the resources. Destructors of variables with automatic, thread local and static storage durations are not called. Functions passed to at_quick_exit() or atexit() are not called. Whether open resources such as files are closed is implementation defined. If exit_code is EXIT_FAILURE, an implementation-defined status, indicating unsuccess

Defined in header <string.h> char *strrchr( const char *str, int ch ); Finds the last occurrence of ch (after conversion to char as if by (char)ch) in the null-terminated byte string pointed to by str (each character interpreted as unsigned char). The terminating null character is considered to be a part of the string and can be found if searching for '\0'. The behavior is undefined if str is not a pointer to a null-terminated byte string. Parameters str - pointer t

Usage return statement: as the declaration of the statement

Defined in header <signal.h> #define SIGTERM /*implementation defined*/ #define SIGSEGV /*implementation defined*/ #define SIGINT /*implementation defined*/ #define SIGILL /*implementation defined*/ #define SIGABRT /*implementation defined*/ #define SIGFPE /*implementation defined*/ Each of the above macro constants expands to an integer constant expression with distinct values, which represent different signals sent to the program. Constant

A collection of operators that do not fit into any of the other major categories. Operator Operator name Example Description (...) function call f(...) call the function f(), with zero or more arguments , comma operator a, b evaluate expression a, disregard its return value and complete any side-effects, then evaluate expression b, returning the type and the result of this evaluation (type) type cast (type)a cast the type of a to type ? : conditional operator

Defined in header <threads.h> int mtx_trylock( mtx_t *mutex ); (since C11) Tries to lock the mutex pointed to by mutex without blocking. Returns immediately if the mutex is already locked. Prior calls to mtx_unlock on the same mutex synchronize-with this operation (if this operation succeeds), and all lock/unlock operations on any given mutex form a single total order (similar to the modification order of an atomic). Parameters mutex - pointer to the mutex to lock