C / C++ / MFC

how to change data of struture object in file

26-Jun-09 5:00

Why don't you ask in the article thread?
Smile | :)

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ashish8patil26-Jun-09 4:11

ashish8patil

26-Jun-09 4:11

Hello All ,
Sorry i am posting all code ,
i this code it is writting & reading stuct data ,BUt not changing that data i want change that data

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

struct MyRecord {
char name[80];
double balance;
unsigned long account_num;
};

int main()
{
struct MyRecord acc;

strcpy(acc.name, "R");
acc.balance = 1.3;
acc.account_num = 34;

ofstream outbal("balance", ios::out | ios::binary);
if(!outbal) {
cout << "Cannot open file.\n";
return 1;
}

outbal.write((char *) &acc, sizeof(struct MyRecord));
outbal.close();

ifstream inbal("balance", ios::in | ios::binary);
if(!inbal) {
cout << "Cannot open file.\n";
return 1;
}

inbal.read((char *) &acc, sizeof(struct MyRecord));

cout << acc.name << endl;
cout << "Account # " << acc.account_num;
cout.precision(2);
cout.setf(ios::fixed);
cout << endl << "Balance: $" << acc.balance;

inbal.close();
return 0;
}

Re: how to change data of struture object in file

David Crow26-Jun-09 4:40

David Crow

26-Jun-09 4:40

ashish8patil wrote:
i this code it is writting & reading stuct data ,BUt not changing that data...

Of course it's not changing the data. You've shown no code to do that.

ashish8patil wrote:
...i want change that data

So change it and call the write() method again. What's the problem? Confused | :confused:

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Re: how to change data of struture object in file

CPallini26-Jun-09 4:56

Problem using MsiGetProductInfo for retreving the product version

26-Jun-09 4:56

Plese use the code block button for posting code snippets.

ashish8patil wrote:
i this code it is writting & reading stuct data ,BUt not changing that data i want change that data

What do you mean with this? Your program sets the fields of the struct, then write it to disk, and finally read it again from disk. How these operations are supposed to change the content? What is your expected output?
Smile | :)

V K 226-Jun-09 2:48

V K 2

26-Jun-09 2:48

I am using the below code snippet for retreving the Product version . This works fine when I write this in a sample application. I am retreiving the correct product version Eg. "10.9.8". But when I integrated this code snippet with my project code. then str string in below code gives me return value as "?#@!" Can I know what could have been the problem.

CString GetInstalledIntouchCEVersion()
{
UINT returnCode;
char pProductCode[39]={0};
//char lpVersion[50] = {0};
LPSTR str;
DWORD cchVersionName;
str = new TCHAR[50];
// Here Guid is MSI product upgrade code for InTouchCE
returnCode = MsiEnumRelatedProducts("Our Product Code",0,0,pProductCode);
if ( ERROR_SUCCESS == returnCode )
{

UINT ret = MsiGetProductInfo(pProductCode,INSTALLPROPERTY_VERSIONSTRING,str,&cchVersionName);
}
return str;
}

Re: Problem using MsiGetProductInfo for retreving the product version

Rajesh R Subramanian26-Jun-09 3:26

Program not giving desired output

26-Jun-09 3:26

Venkat KR wrote:
if ( ERROR_SUCCESS == returnCode )
{

UINT ret = MsiGetProductInfo(pProductCode,INSTALLPROPERTY_VERSIONSTRING,str,&cchVersionName);
}
return str;

I see you are 'returning' str with no regards to what MsiGetProductInfo() returned. Unsure | :~

Can you check the return value?

It is a crappy thing, but it's life -^ Carlo Pallini

Razanust26-Jun-09 2:31

Razanust

26-Jun-09 2:31

#include <stdio.h>
#include <stdlib.>
#include <string>
main()
{
char s[80];
int i=0;
FILE *fp;
fp=fopen("POEM.TXT","w+");
if(fp==NULL)
{
puts("Cannot open file");
exit(1);
}
puts("Enter any string");
while ( strlen(gets(s)) >; 0 );
{

fputs(s,fp);
fputs("\n",fp);
}

fclose(fp);

}

This prog should write the given output to the text file. But inspite of not giving any errors the text file remains empty!!!

Rajesh R Subramanian26-Jun-09 2:37

26-Jun-09 2:37

Take a look at the code you've posted! It is not properly formatted and worse yet some parts are not visible. Please "edit" your post, select all the code and click the "code block" formatting option.

It is a crappy thing, but it's life -^ Carlo Pallini

CPallini26-Jun-09 2:40

26-Jun-09 2:40

Razanust wrote:
while ( strlen(gets(s)) >; 0 );

This line should be

while ( strlen(gets(s)) > 0 )

i.e. without the semicolon at the end.
Smile | :)

Razanust27-Jun-09 5:36

Razanust

27-Jun-09 5:36

Thanks a million!

CPallini28-Jun-09 0:36

How to change structure data written in the file. in v++

28-Jun-09 0:36

You are welcome.
Smile | :)

ashish8patil26-Jun-09 2:12

ashish8patil

26-Jun-09 2:12

Hello All,

I have structure
student{ char name[10];
int id ;
};

int main()
{
student s ;
///filling data to s
//writting s to file temp.dat
//reading s from temp.dat
}
Now i want to change s.name .
what should i do
thanks all.

Re: How to change structure data written in the file. in v++

Rajesh R Subramanian26-Jun-09 2:14

Re: How to change structure data written in the file. in v++

26-Jun-09 2:14

_tcscpy(s.name, _T("Hello")); ?

Are you looking for something else?

It is a crappy thing, but it's life -^ Carlo Pallini

CPallini26-Jun-09 2:28

Re: How to change structure data written in the file. in v++

26-Jun-09 2:28

Sorry sir, it doesn't fit on UNICODE builds. Poke tongue | ;-P

You may use _T("hi"), however... Roll eyes | :rolleyes:

Rajesh R Subramanian26-Jun-09 2:38

Re: How to change structure data written in the file. in v++

26-Jun-09 2:38

Well, that's an essay for another time. Use TCHAR instead of char while writing code on Windows. Smile | :)

It is a crappy thing, but it's life -^ Carlo Pallini

ashish8patil26-Jun-09 4:07

ashish8patil

26-Jun-09 4:07

thanks for reply please see my new post

how to open rtf file

santhosh-padamatinti26-Jun-09 1:30

santhosh-padamatinti

26-Jun-09 1:30

hi,

I wrote a dialog based application, in that i am taken one button for opening a rtf file whcih located in my desktop. Please tell me how to open that rtf file directly when i am clicking the button, I tried WinExec()method for opening, but i am not getting

thanx in advance.....

sampath-padamatinti

Re: how to open rtf file

Rajesh R Subramanian26-Jun-09 1:35

Gettin the pointers of all open windows

26-Jun-09 1:35

You may use ShellExecute()[^] and that will open an RTF file (or any other file) with the default application registered to handle it.

Here is a nice guide: A newbie's elementary guide to spawning processes[^]

It is a crappy thing, but it's life -^ Carlo Pallini

prithaa26-Jun-09 1:11

prithaa

26-Jun-09 1:11

Hello,

By which function of MDIFrameWnd can I get the list of all open windows.

Pritha

Re: Gettin the pointers of all open windows

Rajesh R Subramanian26-Jun-09 1:12

Re: Gettin the pointers of all open windows

26-Jun-09 1:12

All open windows owned by your application or all windows on the running on current desktop?

It is a crappy thing, but it's life -^ Carlo Pallini

prithaa26-Jun-09 1:17

prithaa

26-Jun-09 1:17

Thanks for your reply

I did not understand your reply.

I wanted to know the function by which I can get the pointers of all the open windows created by CreateNewChild().

Pritha

Re: Gettin the pointers of all open windows

Rajesh R Subramanian26-Jun-09 1:34