what's wrong with this code ?

[abhiboy007]

i want to edit contents of binary file in which records are stored
record is a structure.

ftp = fopen("stock.dat", "a+" );

switch(ch)
{
case 2: // option to edit record
{
long int rec = 0, loc = 0;
printf("\n Enter record no :- ");
scanf("%ld", &rec);
loc = ( rec - 1 ) * sizeof(a) + ( rec - 1 );
fseek( fpt, loc, 0 );
getdata();
fread( &a, sizeof(a), 1, fpt );
break;
}
}

now problem is that file pointer is positioning properly
but the record is not updated.
please help.

[quzah]

Originally posted by abhiboy007
i want to edit contents of binary file in which records are stored
record is a structure.

ftp = fopen("stock.dat", "a+" ); 1

switch(ch) 2
{
case 2: // option to edit record
{
long int rec = 0, loc = 0; 3
printf("\n Enter record no :- ");
scanf("%ld", &rec); 4
loc = ( rec - 1 ) * sizeof(a) + ( rec - 1 ); 5
fseek( fpt, loc, 0 ); 6
getdata(); 7:
fread( &a, sizeof(a), 1, fpt );
break;
}
}

now problem is that file pointer is positioning properly
but the record is not updated.
please help.

1: you don't test the return value
2: where the hell did ch come from?
3: While valid, it is 'Bad Form(TM)'.
4: What is 'rec'?
5: What is 'a'?
6: Poor use of fseek.
7: What the hell is this?

The rest has already been covered.

Quzah.

[BillD]

I'm just a beginner but I do notice that, in your 1st line:

ftp = fopen("stock.dat", "a+" ); 1

shouldn't the ftp be fpt as follows in the remaining code ?