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Checking for File Existance

Posted on 2007-11-27
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Last Modified: 2010-04-21
I am not sure why this is so difficult for me. I am using Borland 4.5.2 (I am building a 16-bit app) , and I just want to check if a file exists and set a boolean that can be used later. I have found code snippets by 'Googling' but they don't work. Please incude any #include's that are required to make this work.
this doesn't work for me....

#include <string>
#include <iostream>
#include <fstream>
bool flag = false;
fstream fin;
fin.open("data.txt",ios::in);
if( fin.is_open() )
{
cout<<"file exists"<<endl;
flag=true;
}
fin.close();

in the above code's case, it assumes a later version of the fstream library than comes packaged with the Borland 4.5.2 I am using.
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Question by:dan4good
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4 Comments
 
LVL 30

Expert Comment

by:Axter
ID: 20358807
>>this doesn't work for me....
Don't use it.
You should not use a file open method to test for file existence.

It's inefficient, and does not work as well as other methods.

You should use stat method instead.
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Accepted Solution

by:
Axter earned 500 total points
ID: 20358816
Here's example code:

#include <sys/stat.h>
 
bool FileExist(const char* FileName)
{
     struct stat my_stat;
     return (stat(FileName, &my_stat) == 0);
}
 
int main(int argc, char* argv[])
{
     bool v1 = FileExist("c:\\autoexec.bat");
     bool v2 = FileExist("c:\\nofile.bat");
     bool v3 = FileExist("c:\\config.sys");
     bool v4 = FileExist("c:\\nofile2.bat");
     return 0;
}

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LVL 86

Expert Comment

by:jkr
ID: 20358819
You could just use

#include <sys/stat.h>

bool file_exists(const char* pName)
{
  struct stat st;

  if (-1 == stat(pName,&st)) return false;

  return true;
}
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Author Closing Comment

by:dan4good
ID: 31411206
Thanks , great response time as well.
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