access violation problem

[JasBascom]

int main()
{
char record_typec = 'c';
record_typec = toupper(record_ typec);
* rec->Newcrecord.rec ord_type = record_typec;

etc
etc

\************** *************** *************** *\

I've run a debug on the program and this is where I'm encountering the access
violation problem. I've tried the dot operator to access the structure but that
doesn't appear to work. How can change the syntax and avoid the access
violation error?

[JasBascom]

thank you so far, but i feel the sort is ok, i won't know until I can get the
sort file to work. The sort file does create a text file on the floppy disk,
but when I go to execute the program there is an access violation error
concerning the sort file.
Thanks again for your help, can someone run the program rthrough their own
compiler just to check.
The program is suppose to open a binary file (in this case validdata), and sort
the contents of validdata and then write this to sort_file.
if anyone is feel brave or a little bored can they actually write a program for
me that opens a text file and a binary file and get the contents of the binary
file to the sort_file.

[John Harrison]

Comments follow.

I see you didn't follow my earlier advice not to try to do too much at once.
Your post is full of code which does nothing like what you hope it does.
This isn't surprising, programming is hard and you are new at this.

There is a way to avoid wasting your time writing lots of code which will
just have to be thrown away. The way is to write small amounts of code at a
time (literally 3, 4, 5 lines at most), and get those lines working before
you write any more. This is how professionals work, although their
experience means that they can write code in bigger chunks than 3 - 5 lines.

The way to have you tearing your hair out is to write lots of code without
doing any testing at all.

Don't worry newbies never follow this advice. You'll find out the hard way.
"JasBascom" <ja*******@aol. com> wrote in message
news:20******** *************** ****@mb-m11.aol.com...

The full program is follows. Thank you john for pointing out the access
violation error. i also have a problem with the declaring of an fstream object - sort_file. For some reason my debugger is unable to move beyond that point in the code.

I would also like to have rec.Newcrecord. record_type assigned the character 'c' and to toupper the record_type. can you please help in both instances.

#include <iostream>
#include <iomanip>
#include <fstream>
#include <cstring>
#include <cstdlib>
using namespace std;

struct crecord {
char record_type;
char customercode[5];
char customername[21];
char customeraddress[61];
char customerbalance ;
char creditlimit;
int Totalbalance;
int Totalcreditlimi t;

};
struct irrecord {
char record_type;
char customercode[5];
char partnum[6];
char issue_rec[5];

};
struct drecord {
char record_type;
char customercode[5];
};
int loop = 200;
long offset = 1;

union Allrecords{
struct crecord Newcrecord;
struct irrecord Newirrecord;
struct drecord Newdrecord;

};
union Allrecords* rec;


void sort_function( union Allrecords* rec, fstream& validdata )
{

union Allrecords *str_ptr1, *str_ptr2, tempstr;
for(int i =0; i< loop; i++)
while( strcmp(str_ptr1[i].Newcrecord.cus tomercode, '\0') ||
strcmp(str_ptr1[i].Newdrecord.cus tomercode, '\0') ||
strcmp(str_ptr1[i].Newirrecord.cu stomercode, '\0'))
{
str_ptr2 = str_ptr1 + 1;//set to next element.

for( i=0; i<loop; i++)
while( strcmp(str_ptr2[i].Newcrecord.cus tomercode, '\0') ||
strcmp(str_ptr2[i].Newdrecord.cus tomercode, '\0'))
{
for(int i=0; i<loop; i++)
if( strcmp( str_ptr1[i].Newirrecord.cu stomercode,
str_ptr2[i].Newirrecord.cu stomercode + 1))
{
tempstr = *str_ptr1;
*str_ptr1 = *str_ptr2;
*str_ptr2 = tempstr;

}
*str_ptr1++;//incremented, so that the same code isn't sorted again
}
str_ptr2++;
}

}
This function will crash as soon as it is entered. The problem is the
uninitialised pointers str_ptr1 and str_ptr2. This is the same mistake you
made in main. More seriously this code performs nothing like a sort, not
even close, it should be thrown away.



int main()
{
const char sorted_file[] = "A:\\514650SDP2 .txt";
const char outfile[] = "A:\\514650VDP1 .bin";


long offset = 1;
int filesize;
int reccount;

fstream sort_file;
fstream validdata;

sort_file.open( "A:\\514650SDP2 .txt", ios::out);
if(!sort_file)
{
cout<<"Cannot create file"<< endl;
return EXIT_FAILURE;
};

validdata.open( "A:\\514650VDP1 .bin", ios::in || ios::binary);
if(!validdata)
{
cout<<" Cannot find file"<<endl;
return EXIT_FAILURE;
};
validdata.seekg (-offset, ios::end);
filesize = validdata.tellg ();
validdata.seekg (offset, ios::beg);
What is this? Why seek to one byte before then end of the file? What do you
think that achieves?

reccount = sizeof(filesize )/sizeof(Allrecor ds);
This is wrong. Should be filesize not sizeof(filesize ). This is a good
example of where you are gonig wrong. Obviously you cannot go any further
until you have worked out the number of records in the file. Until you can
do this the rest of your program isn't going to work. So you should have
written the above code, and then STOPPED THERE! Tested your code and seen if
you calculated the number of records correctly. Then you can carry on and
write some more code. At the moment your code doesn't work, and you have no
idea of its the number of records that is wrong, or something completely
different.

rec = new(Allrecords[reccount]);


validdata.read( (char*) rec, filesize);//read the whole file.

for(int i =0; i <reccount; i++)
{
switch(rec[i].Newdrecord.rec ord_type)
{
case 'c':
case 'C':
case 'i':
case 'I':
case 'r':
case 'R':
case 'd':
case 'D':
sort_function(r ec, validdata);
This seems a bit confused, are you trying to sort all the records or just
one record? I presume you are trying to sort all the records, but then why
is the sort_function call in a loop?
default:;
};

};

return 0;

}

Seriously the best advice would be to throw this code away and take my
advice to write the program a little bit at a time. You are just heading for
weeks and weeks of frustration any other way.

john

[John Harrison]

"JasBascom" <ja*******@aol. com> wrote in message
news:20******** *************** ****@mb-m11.aol.com...

thank you so far, but i feel the sort is ok, i won't know until I can get the sort file to work.
That's the problem isn't it? Suppose you get the sort file to work, maybe
the changes you make as a result of that, will mean that you have to rewrite
the sort function.

For the record the sort function is not remotely right.
The sort file does create a text file on the floppy disk,
but when I go to execute the program there is an access violation error
concerning the sort file.
Thanks again for your help, can someone run the program rthrough their own
compiler just to check.
The program is suppose to open a binary file (in this case validdata), and sort the contents of validdata and then write this to sort_file.
if anyone is feel brave or a little bored can they actually write a program for me that opens a text file and a binary file and get the contents of the binary file to the sort_file.

Something like this (untested, but please test it your self!)

ifstream validdata("myfi le", ios::in|ios::bi nary);
validdata.seekg (0, ios::end);
filesize = validdata.tellg ();
recount = filesize/sizeof(Allrecor ds);
rec = new Allrecords[reccount];
validdata.seekg (0, ios::beg);
validdata.read( rec, filesize);
validdata.close ();

john

[David Harmon]

On Fri, 20 Feb 2004 18:32:29 -0000 in comp.lang.c++, "John Harrison"
<jo************ *@hotmail.com> was alleged to have written:

"JasBascom" <ja*******@aol. com> wrote in message
news:20******* *************** *****@mb-m11.aol.com...

thank you so far, but i feel the sort is ok, i won't know until I can get

the

sort file to work.

That's the problem isn't it? Suppose you get the sort file to work, maybe
the changes you make as a result of that, will mean that you have to rewrite
the sort function.

Ditto. Comment out the sort function and don't even worry about it
until the program reads and writes the file without sorting it.