c program to print date

This c program prints current system date. To print date we will use getdate function.

C programming code

#include<stdio.h>
#include<conio.h>
#include<dos.h>
 
main()
{
   struct date d;
 
   getdate(&d);
 
   printf("Current system date is %d/%d/%d",d.da_day,d.da_mon,d.da_year);
   getch();
   return 0;
}

c program to add two complex numbers

c program to add two complex numbers :- This program calculate the sum of two complex numbers which will be entered by the user and then prints it. User will have to enter the real and imaginary parts of two complex numbers. In our program we will add real parts and imaginary parts of complex numbers and prints the complex number, i is the symbol used for iota. For example if user entered two complex numbers as (1 + 2i) and (4 + 6 i) then output of program will be (5+8i). A structure is used to store complex number.

C programming code

#include <stdio.h>
 
struct complex
{
   int real, img;
};
 
main()
{
   struct complex a, b, c;
 
   printf("Enter a and b where a + ib is the first complex number.\n");
   printf("a = ");
   scanf("%d", &a.real);
   printf("b = ");
   scanf("%d", &a.img);
   printf("Enter c and d where c + id is the second complex number.\n");
   printf("c = ");
   scanf("%d", &b.real);
   printf("d = ");
   scanf("%d", &b.img);
 
   c.real = a.real + b.real;
   c.img = a.img + b.img;
 
   if ( c.img >= 0 )
      printf("Sum of two complex numbers = %d + %di\n",c.real,c.img);
   else
      printf("Sum of two complex numbers = %d %di\n",c.real,c.img);
 
   return 0;
}

C programming code using random function(Turbo C compiler only)

#include<stdio.h>
#include<conio.h>
#include<stdlib.h>
 
main()
{
   int n, max, num, c;
 
   printf("Enter the number of random numbers you want ");
   scanf("%d",&n);
 
   printf("Enter the maximum value of random number ");
   scanf("%d",&max);
 
   printf("%d random numbers from 0 to %d are :-\n",n,max);
   randomize();
 
   for ( c = 1 ; c <= n ; c++ )
   {
      num = random(max);
      printf("%d\n",num);
 
   }
 
   getch();
   return 0;
}

c program to generate random numbers

This c program generates random numbers using random function, randomize function is used to initialize random number generator. If you don't use randomize function then you will get same random numbers each time you run the program.

C programming code using rand

#include <stdio.h>
#include <stdlib.h>
 
int main() {
  int c, n;
 
  printf("Ten random numbers in [1,100]\n");
 
  for (c = 1; c <= 10; c++) {
    n = rand()%100 + 1;
    printf("%d\n", n);
  }
 
  return 0;
}

c program to delete a file

This c program deletes a file which is entered by the user, the file to be deleted should be present in the directory in which the executable file of this program is present. Extension of the file should also be entered, also note that deleted file doesn't go to recycle bin, remove macro is used to delete the file. If there is an error in deleting the file then an error will be displayed using perror function.

C programming code

#include<stdio.h>
 
main()
{
   int status;
   char file_name[25];
 
   printf("Enter the name of file you wish to delete\n");
   gets(file_name);
 
   status = remove(file_name);
 
   if( status == 0 )
      printf("%s file deleted successfully.\n",file_name);
   else
   {
      printf("Unable to delete the file\n");
      perror("Error");
   }
 
   return 0;
}

c program to list files in directory

This program list all files present in a directory/folder in which this executable file is present. For example if this executable file is present in C:\\TC\\BIN then it will lists all the files present in C:\\TC\\BIN.

C programming code

#include<stdio.h>
#include<conio.h>
#include<dir.h>
 
main()
{
   int done;
   struct ffblk a;
 
   printf("Press any key to view the files in the current directory\n");
 
   getch();
 
   done = findfirst("*.*",&a,0);
 
   while(!done)
   {
      printf("%s\n",a.ff_name);
      done = findnext(&a);
   }
 
   getch();
   return 0;
}

c program to merge two files

This c program merges two files and store their contents in an another file. The files which are to be merged are opened in read mode and the file which contains content of both the files is opened in write mode. To merge two files first we open a file and read it character by character and store the read contents in another file then we read the contents of another file and store it in file, we read two files until EOF ( end of file ) is reached.

C programming code

#include<stdio.h>
#include<conio.h>
#include<stdlib.h>
 
main()
{
   FILE *fs1, *fs2, *ft;
 
   char ch, file1[20], file2[20], file3[20];
 
   printf("Enter name of first file ");
   gets(file1);
 
   printf("Enter name of second file ");
   gets(file2);
 
   printf("Enter name of file which will store contents of two files ");
   gets(file3);
 
   fs1 = fopen(file1,"r");
   fs2 = fopen(file2,"r");
 
   if( fs1 == NULL || fs2 == NULL )
   {
      perror("Error ");
      printf("Press any key to exit...\n");
      getch();
      exit(EXIT_FAILURE);
   }
 
   ft = fopen(file3,"w");
 
   if( ft == NULL )
   {
      perror("Error ");
      printf("Press any key to exit...\n");
      exit(EXIT_FAILURE);
   }
 
   while( ( ch = fgetc(fs1) ) != EOF )
      fputc(ch,ft);
 
   while( ( ch = fgetc(fs2) ) != EOF )
      fputc(ch,ft);
 
   printf("Two files were merged into %s file successfully.\n",file3);
 
   fclose(fs1);
   fclose(fs2);
   fclose(ft);
 
   getch();
   return 0;
}