c program to compare two files without using predefined Function

c program to compare two files without using predefined Function

#include  

 void main()  
 { 
    FILE *fp1, *fp2, *fopen(); 
    int ca, cb; 
    char fname1[40], fname2[40] ;  
    printf("Enter name of first file :") ; 
    gets(fname1); 
    printf("Enter name of second file:"); 
    gets(fname2); 
    fp1 = fopen( fname1,  "r" );       /* open file1 for reading */ 
    fp2 = fopen( fname2,  "r" ) ;      /* open file 2 for reading */  
    if ( fp1 == NULL )      /* check does file exist etc */ 
    { 
        printf("Cannot open %s for reading \n", fname1 ); 
        exit(1);    /* terminate program */ 
    } 
    else if ( fp2 == NULL ) 
    { 
        printf("Cannot open %s for reading \n", fname2 ); 
        exit(1);    /* terminate program */ 
    } 
    else   /* both files opened successfully  */ 
    { 
        ca  =  getc( fp1 ) ;   
        cb  =  getc( fp2 ) ; 
        while ( ca != EOF   &&   cb != EOF   &&   ca == cb  ) 
        { 
            ca  =  getc( fp1 ) ;   
            cb  =  getc( fp2 ) ; 
        } 
        if (  ca == cb ) 
            printf("Files are identical \n"); 
        else if ( ca !=  cb ) 
            printf("Files differ \n" ); 
        
        fclose ( fp1 );    
        fclose ( fp2 ); 
    } 
 }