Header files “stdio.h” and “stdlib.h” in C
stdio.h
The header file stdio.h stands for Standard Input Output. It has the information related to input/output functions.
Here is the table that displays some of the functions in stdio.h in C language,
| Sr.No. | Functions & Description |
|---|
| 1 | printf()
It is used to print the strings, integer, character etc on the output screen.
|
| 2 | scanf()
It reads the character, string, integer etc from the keyboard.
|
| 3 | getc()
It reads the character from the file.
|
| 4 | putc()
It writes the character to the file.
|
| 5 | fopen()
It opens the file and all file handling functions are defined in stdio.h header file.
|
| 6 | fclose()
It closes the opened file.
|
| 7 | remove()
It deletes the file.
|
| 8 | fflush()
It flushes the file.
|
Here is an example of stdio.h in C language,
Example
Live Demo
#include<stdio.h>
int main () {
char val;
printf("Enter the character: \n");
val = getc(stdin);
printf("Character entered: ");
putc(val, stdout);
return(0);
}Output
Here is the output
Enter the character: s
Character entered: s
stdlib.h
The header file stdlib.h stands for Standard Library. It has the information of memory allocation/freeing functions.
Here is the table that displays some of the functions in stdlib.h in C language,
| Sr.No. | Functions & Description |
|---|
| 1 | malloc()
It allocates the memory during execution of program.
|
| 2 | free()
It frees the allocated memory.
|
| 3 | abort()
It terminates the C program.
|
| 4 | exit()
It terminates the program and does not return any value.
|
| 5 | atol()
It converts a string to long int.
|
| 6 | atoll()
It converts a string to long long int.
|
| 7 | atof()
It converts a string to floating point value.
|
| 8 | rand()
It returns a random integer value
|
Here is an example of stdlib.h in C language,
Example
Live Demo
#include <stdio.h>
#include<stdlib.h>
int main() {
char str1[20] = "53875";
char str2[20] = "367587938";
char str3[20] = "53875.8843";
long int a = atol(str1);
printf("String to long int : %d\n", a);
long long int b = atoll(str2);
printf("String to long long int : %d\n", b);
double c = atof(str3);
printf("String to long int : %f\n", c);
printf("The first random value : %d\n", rand());
printf("The second random value : %d", rand());
return 0;
}Output
Here is the output
String to long int : 53875
String to long long int : 367587938
String to long int : 53875.884300
The first random value : 1804289383
The second random value : 846930886
Published on 23-Oct-2018 15:58:13
