C stdio.h Library Function

C stdio.h Library Function: The <stdio.h> can be defined as “Standard input-output header file“. And the stdio.h header defines three variable types, several macros, and various functions for performing input and output.

Library Variables

Variable	Description
size_t	This is the unsigned integral type and is the result of the size of the keyword.
FILE	It is an object type suitable for storing information for a file stream
fpos_t	It is an object type suitable for storing any position in a file

List of C Inbuilt Functions in stdio.h file.

Function	Description
printf( )	It is used to print the character, string, float, integer, octal and hexadecimal values onto the output screen
scanf( )	It is used to read a character, string, numeric data from the keyboard
getc( )	reads character from a file
gets( )	reads line from the keyboard
getchar( )	reads character from the keyboard
puts( )	writes a line to o/p screen
putchar()	writes a character to the screen
clearerr()	function clears the error indicators
f open()	All file handling functions are defined in stdio.h header file
f close()	closes an opened file
getw()	reads an integer from a file
putw()	writes an integer to file
f getc()	reads a character from a file
putc()	writes a character to file
f putc()	writes a character to file
f gets()	reads a string from a file, one line at a time
f puts()	writes a string to a file
f eof()	finds the end of file
f getchar	reads a character from the keyboard
f getc()	reads a character from the file
f printf()	writes formatted data to a file
f scanf()	reads formatted data from a file
f getchar	reads a character from the keyboard
f putchar	writes a character from the keyboard
f seek()	moves file pointer position to a given location
SEEK_SET	moves file pointer position to the beginning of the file
SEEK_CUR	moves file pointer position to a given location
SEEK_END	moves file pointer position to the end of file
f tell()	gives the current position of file pointer
rewind()	moves file pointer position to the beginning of the file
putc()	writes a character to file
sprint()	writes formatted output to the string
sscanf()	Reads formatted input from a string
remove()	deletes a file
fflush()	flushes a file

Example

#include<stdio.h> 
void fun(int x) 
{ 
   x = 30; 
}
int main(void) 
{ 
    int x = 20; 
    fun(x); 
    printf("x = %d", x); 
    return 0; 
}

Output
x = 20