Program which copies one file to another

Description:

In this program we have to use the file functions to perform the copy operation from one file to another file.

Algorithm:

Step 1: Start

Step 2: read command line arguments

Step 3: check if no of arguments =3 or not. If not print invalid no of arguments

Step 4: open source file in read mode

Step 5: if  NULL pointer, then print source file can not be open

Step 6: open destination file in write mode

Step 7: if NULL pointer, then print destination file can not be open

Step 8 : read a character from source file and write to destination file until EOF

Step 9: Close source file and destination file

Step 10: Stop 

Program:

#include <stdio.h>

#include <conio.h>

#include <process.h>

void main(int argc, char *argv[])

{

 FILE *fs,*ft;

 char ch;

 clrscr();

 if(argc!=3)

            {

                         puts("Invalid number of arguments.");

                         exit(0);

  }

 fs = fopen(argv[1],"r");

 if(fs==NULL)

            {

 puts("Source file cannot be opened.");

 exit(0);

 }

 ft = fopen(argv[2],"w");

 if (ft==NULL)  // check the condition if the file pointer is NULL or not

 {

 puts("Target file cannot be opened.");

 fclose(fs);

 exit(0);

 }

 while(1)

 {

            ch=fgetc(fs);

             if (ch==EOF) // check the condition if the file is end or not

  break;

            else

            fputc(ch,ft);

  }

  fclose(fs);

  fclose(ft);

  getch();

}

Output:

source.c

           this is source text

ouput.c

Command line arguments

source.c ouput.c

source.c

           this is source text

ouput.c

           this is source text

Command line arguments

source.c

Invalid number of arguments.

Conclusion: the program is error free

VIVA QUESATIONS:

1) What is file ?

Ans: The collection of alphabets is called file

2) What are the various operations performed on the file ?

Ans: fopen(), fread(), fwrite(), fclose() etc..,

3) What is the use of file pointer ?

Ans: The file pointer must be used in subsequent operations on the file