dos.h header in C with examples

dos.h is a header file of C Language. This library has functions that are used for handling interrupts, producing sound, date and time functions, etc. It is Borland specific and works in compilers like Turbo C Compiler.
Below are the functions supported by this library:

1. delay(): The delay() function in C is used to stop the execution of the program for some period of time.
   Syntax:
   
   

   delay(unsigned int)
   

   Parameters: It accepts a time in milliseconds to stop the execution of the program to that period of time.

   Below is the program to illustrate delay():

   
   
   

   // C program to implement delay()
   #include <dos.h>
   #include <stdio.h>
   #include <stdlib.h>
   
   // Driver Code
   int main()
   {
       printf("Takes 10 sec and exit.\n");
   
       // Delay the program execution
       // for 1 second
       delay(10000);
   
       return 0;
   }
2. sleep(): The sleep() function in C is used to delay the execution of the program for some period of time.
   Syntax:

   sleep(unsigned seconds)
   

   Parameters: It accepts a time in seconds to delay the execution of the program to that period of time.

   Below is the program to illustrate sleep():

   // C program to implement sleep()
   #include <dos.h>
   #include <stdio.h>
   #include <stdlib.h>
   
   // Driver Code
   int main()
   {
       printf("Wait 2 sec and exit.\n");
   
       // Delay the program execution
       // for by 2 seconds
       sleep(2);
   
       return 0;
   }
3. getdate(): The getdate() function in C is used to get the current Date of the system.

   Syntax:

   getdate(struct date d)
   

   Parameters: It accepts a structure date which is defined in dos.h library itself. To print the date it uses function da_day(), da_mon() and da_year().

   Below is the program to illustrate getdate():

   // C program to implement getdate()
   #include <dos.h>
   #include <stdio.h>
   #include <stdlib.h>
   
   // Driver Code
   int main()
   {
       // Structure of date
       struct date a;
   
       // Function call to get the date
       // of the system
       getdate(&a);
   
       // Print the date, month and year
       printf("The Date is: %d/%d/%d\n", a.da_day,
              a.da_mon,
              a.da_year);
   
       return 0;
   }
4. gettime(): The gettime() function in C is used to get the Time shown by the System.

   Syntax:

   gettime(struct time t)
   

   Parameters: It accepts a structure time which is defined in dos.h library itself. To print the date it uses function ti_hour(), ti_min() and ti_sec().

   Below is the program to illustrate gettime():

   // C program to implement gettime()
   #include <dos.h>
   #include <stdio.h>
   #include <stdlib.h>
   
   // Driver Code
   int main()
   {
       // Structure of time
       struct time t;
   
       // Function call to get the time
       // of the system
       getdate(&t);
   
       // Print the hour, minutes and second
       printf("The time is: %d : %d : %d\n", x.ti_hour,
              x.ti_min,
              x.ti_sec);
   
       return 0;
   }
5. sound(): The sound() function in C is used to play different sound on different frequency on our system.

   Syntax:

   sound(int frequency)
   

   Parameters: It accepts a frequency and play the sound of that frequency in our system.

   Below is the program to illustrate sound():

   // C program to implement sound()
   #include <dos.h>
   #include <stdio.h>
   #include <stdlib.h>
   
   // Driver Code
   int main()
   {
       // Initialise frequency
       int x = 200;
   
       // Loop for playing sound of
       // increasing frequency
       for (; x < 1000; x++) {
   
           // Function to play sound
           sound(x);
   
           delay(25);
       }
   
       // To stop the frequency
       nosound();
       return 0;
   }
6. nosound(): The nosound() function in C is used to stop the sound played by souns() function.

   Syntax:

   nosound()
   

   Parameters: It doesn’t accepts any parameters.

   Below is the program to illustrate nosound():

   // C program to implement nosound()
   #include <dos.h>
   #include <stdio.h>
   #include <stdlib.h>
   
   // Driver Code
   int main()
   {
       // Initialise frequency
       int x = 200;
   
       // Function call to play sound
       // with frequency 200htz
       sound(x);
   
       // Delay sound for 1 sec
       delay(1000);
   
       // To stop the sound
       nosound();
       return 0;
   }