Thread: Why does this not read in correctly?

The data is written correctly to the external file. In the correct order and format. But when read back in, the format is changed, and the data is not displayed correctly. Is their something wrong with this code? It should be in this order-
MemberNumber MemberName MemberAddress MemberVisits.


while (!feof(memberRead))
{
fscanf (memberRead, "\n%s", MemberData[counter1].membernumber);
fgets(&MemberData[counter1].membername, 30, memberRead);
fgets(&MemberData[counter1].memberaddress, 100, memberRead);
fscanf (memberRead, "%d", &MemberData[counter1].membervisits);
counter1++;
}
m = counter1;
m--;

BlueBob

Can you add your data file as an attachment?

Then someone can show you how to read the file properly, without all this feof() nonsense.

Here ya go, an example of a typical members file.
Whats wrong with using feof? i was told on this board to use it!

BlueBoB

mem1
Scott Harkins
South Cobberville
0
mem2
Brian Hope
North Queensferry
0
mem3
Allister McIntosh
New Jersey
0

Slap me if I'm wrong (quite likely), but is it not easier to read and write the entire MemberData structure to the file using fwrite() and fread() in binary mode?
e.g.

filePtr = fopen(f_name, "wb");
fwrite(&MemberData, sizeof(MD_STRUCT), 1, filePtr);
fclose(filePtr);


dt

lol

If i use a memory dump i will lose marks! Thats why i didnt use it.

I will try to use the one function to read from now on though.

BlueBob

Try this

Code:

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

#define MAX_MEMBERS 10
#define MEM_NAME_LEN    20
#define MEM_ADDR_LEN    20

typedef struct {
    int  membernumber;
    char membername[MEM_NAME_LEN];
    char memberaddress[MEM_ADDR_LEN];
    int  membervisits;
} mem_st;
mem_st MemberData[MAX_MEMBERS];

int main() { 
    char    buff[BUFSIZ];
    int     i, counter1 = 0;
    FILE    *fp;

    /* open the file, check for success */
    fp = fopen( "sample.txt", "r" );
    if ( fp == NULL ) {
        perror( "Cant open" );
        exit( 1 );
    }

    /* read all members, or until the array is full */
    while ( counter1 < MAX_MEMBERS &&
            fgets( buff, BUFSIZ, fp ) != NULL ) {
        sscanf( buff, "Mem%d", &MemberData[counter1].membernumber );

        /* read name and address directly into the array */
        /* if you need to remove the newline, add the code */
        /* if the fgets fails, we've reached the end of file unexpectedly */
        if ( fgets( MemberData[counter1].membername, MEM_NAME_LEN, fp ) == NULL ) break;
        if ( fgets( MemberData[counter1].memberaddress, MEM_ADDR_LEN, fp ) == NULL ) break;

        /* read and scan the number of visits */
        if ( fgets( buff, BUFSIZ, fp ) == NULL ) break;
        sscanf( buff, "%d", &MemberData[counter1].membervisits );

        /* successfully read a complete record */
        counter1++;
    }
    fclose( fp );

    for ( i = 0 ; i < counter1 ; i++ ) {
        printf( "%d %s %s %d\n",
            MemberData[i].membernumber,
            MemberData[i].membername,
            MemberData[i].memberaddress,
            MemberData[i].membervisits );
    }

    return 0; 
}

> Whats wrong with using feof? i was told on this board to use it!
Nothings wrong, it just doesn't tell you what you want to know, so its the wrong function to use in the context in which you were using it.