Program

The function int getchar (void) in Library C takes a character (an unsigned char) from stdin. This function is equivalent to the getc function with the parameter stdin.

The function int putc (int char, FILE * stream) in Library C writes one character (an unsigned char) defined by the parameter char to the given Stream and increases the position

The function int putchar (int char) in standard C Library Writes a character (an unsigned char) defined by the char parameter to stdout.

The function int puts (const char * str) in the standard C library writes a str string to stdout (not writing null characters). A newline character (new line) is appended to the

The function int ungetc (int char, FILE * stream) in the C Library standard pushes the char character (an unsigned char) onto the Stream given to the next character to be read.

The function void perror (const char * str) in the C Library standard prints a message describing the error to stderr. First, the printed string str is followed by a colon and

The header file named stdlib.h in Standard C Library defines four variable types, a number of macros and various functions to implement common features.

The double atof function (const char * str) in Standard C Library converts a string pointed to by parameter str to a floating point number (type double).

The int atoi function (const char * str) in standard C library converts a string pointed to by parameter str to an integer (int type).

The function long int atol (const char * str) in the standard C library converts a string pointed to by parameter str to some long int.

The double strtod function (const char * str, char ** endptr) in Standard C library converts a string pointed to by parameter str to a floating point number (type double).

The function long int strtol (const char * str, char ** endptr, int base) in Standard C library converts part of the original string in str to a value of long int corresponding to

The unsigned function long int strtoul (const char * str, char ** endptr, int base) in Standard C library converts part of the original string in str to a value of long int

The function void * calloc (so-phan-tu, kich-co-phan-tu) allocates the requested memory and returns a pointer to it. The difference between malloc and calloc is: malloc does not

The void free function (void * ptr) frees the previously allocated memory by a call to calloc, malloc, or realloc

The malloc () function allocates the requested memory and returns a pointer to it.

The realloc () function attempts to recover the memory block pointed to by the ptr pointer that was previously allocated with a call to malloc or calloc.

The abort () function stops executing the program abnormally.

Int atexit function (void (* func) (void)) calls function func when the program ends. You can register your end function (func function) wherever you like, but this function will

The void exit (int status) function immediately terminates the calling process. Any file opened by the process is closed and any child process is inherited by the initial process