comparing and checking columns in two files [closed]

Answer 1

I recommend you do make three "Random Access Files" (because they are more organized), but first:

• You need to format each file with the structure It will use, in the first file the structure [1] You just need one member the name (char array), in the second structure [2] you need three members the name (char array) and 2 values (I suppose two integers), and the third stricture is the same as the second so you can re-utilize it.

[1]

/* Struct for the first file. */
typedef {
    char name[4];
} file1_t;

[2]

/* Struct for the second file. */
typedef {
    char name[4];
    int value1, value2;
} file2_t;

• To create those files you will have to use a code like this (Supposing that the file is opened in "wb" mode, but not created):

  /* This is an incomplete example (I can't make your whole Homework)*/
  
  void file2Creator( FILE *fPtr )
  {
      int i; // Counter to create the file.
      file2_t data = { "", 0, 0 }; // A blank example to format the file.
  
      /* You will create 9 consecutive records*/
      for( i = 1; i <= 9; i++ ){
          fwrite( &data, sizeof( file2_t ), 1, fPtr );
      }
  
      fclose( fPtr ); // You can close the file here or later however you need.  
  }
  

• After that you have to fill the blank spaces you made (I suppose the file is opened):

  void fillFile2( FILE *fPtr)
  {
      int position;
      file2_t data = { "", 0, 0 };
  
  
      printf( "Enter the position to fill (1-9) 0 to finish:\n?" );
      scanf( "%d", &position );
  
      while( position != 0 ){
          printf( "Enter the name, and the two other values (integers):\n?" );
          fscanf( stdin, "%s%d%d", data.name, data.value1, data.value2 );
  
          /* You have to seek the pointer. */
          fseek( fPtr, ( position - 1 ) * sizeof( file2_t ), SEEK_SET );
          fwrite( &data, sizeof( file2_t ), 1, fPtr );
          printf( "Enter a new position (1-9) 0 to finish:\n?" );
          scanf( "%d", &position );
      }
  
      fclose( fPtr ); //You can close the file or not, depends in what you need.
  }
  

• Now i imagine that you have the file1, file 2 and file 3 formatted, and the file 1 and 2 are filled, and you want to fill the file 3 how to do it? Simple.

  /* 3 pointers to each file */
  void fillFile3( FILE *f1Ptr, FILE *f2Ptr, FILE *f3Ptr )
  {
      int i, j, k, number;
      char word[ 4 ];
      file1_t data1 = { "" };
      file2_t data2, data3 = { "", 0, 0 };
  
      k = 1;
  
      /* I suppose that files are opened with their correctly FILE pointers. */
      for( i = 1; i <= 5; i++ ){
  
          /* I locate in the "i" position of the file1. */
          fseek( f1Ptr, ( i - 1 ) * sizeof( file1_t ), SEEK_SET );
  
          /* I read the slot. */
          fread( &data1, sizeof( file1_t ), 1, f1Ptr );
  
          /*Now we compare the file2 until we find the correct value, if it is organized we can jump some slots if not compare with all.*/
          for( j = 1; j <= 9, j++ ){
              fseek( f2Ptr, ( j - 1 ) * sizeof( file2_t ), SEEK_SET );
              fread( &data2, sizeof( file2_t ), 1, f2Ptr );
  
              /* We compare the strings, If they are equal we paste the value in file 3*/
              if( strcmp( data1.name, data2.name ) == 0 ){
  
                 /*file 3 is of type of the file 2*/
                 fseek( f3Ptr, ( k - 1 ) * sizeof( file2_t ), SEEK_SET );
                 fwrite( &data2, sizeof( file2_t ), 1, f3Ptr );
                 k++;
                 break;
              }
          }
      }
      fclose( f1Ptr );
      fclose( f2Ptr );
      fclose( f3Ptr );
  }
  

Answer 2

You added a semicolon after the if, and forgot a parenthesis.

if( strcmp( A[i][j], B[i][j] ) == 0 ){
        printf( "%s /n %s  ", strcmp( A[i][j], B[i][j] ) );
}

Answer 3

I am tring to do this program but it just wont run.

#include <stdio.h>
#include <stdlib.h>

int main()
{
    FILE *fp1 ,*fp2;
    char ca , cb;
    int i,j,x,s;
    char A[i][j],B[i][j];
    char file1[1024], file2[1024];

    printf( "Enter file1: ", file1 );
    gets( file1 );
    printf( "Enter file2: ",file2 );
    gets( file2 );
    fp1=fopen( file1, "r");

    if ( fp1 == NULL ){
        printf("Cannot open %s for reading \n", file1 );
        exit(1);
    }

    while ( ( fgets( file1, sizeof file1, stdin ) ) != EOF ){
        for(i=0;i<2500;i++){
            for(j=0;j<5;j++){
                fscanf(fp1,"%s",&A[i][j]);
            }
        }
    }

    fp2 = fopen( file2, "r");

    if ( fp2 == NULL ){
        printf("Cannot open %s for reading \n", file2 );
        exit( 1 );
    }

    while ( fgets ( file2, sizeof file2, stdin) != EOF){
        for( i = 0; i < 2500; i++ ){
            for( j = 0; j < 5; j++ ){
                fscanf(fp2,"%s",&B[i][j]);
            }
        }
    }
    /*Here it was a ; without any sense (after the if)*/
    if( strcmp( A[i][j], B[i][j] ) ) == 0;
    {
        printf( "%s /n %s  ", strcmp( A[i][j], B[i][j] ) );
    }

    fclose(fp1);
    fclose(fp2);

    return 0;
}

the compiler shows syntax error befor "==" token ( 8th line from bottom at strcmp function). Any help ??