__NOTOC__
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{|style=”background:#eceff2″ width=”660px” border=”1″ cellpadding=”5″ cellspacing=”0″
|-
|”’ID”’ ||  
|”’Creation date”’ || September 4, 2008
|-
|”’Platform”’ || S60 3rd Edition, FP2
|”’Tested on devices”’ || Nokia 6220 Classic
|-
|”’Category”’ || Open C/C++
|”’Subcategory”’ || Files/Data
|}

{|style=”background:#eceff2″ width=”660px” border=”1″ cellpadding=”5″ cellspacing=”0″
|-
|”’Keywords (APIs, classes, methods, functions):”’ fstream, stat, FILE, fopen(), fclose(), fstream::open(), fstream::is_open(), fstream::close()
|}

==Overview==

This code snippet shows how to check if a certain file exists using C or C++. The portable way that works in C and C++, is to check if a file exists with the <tt>stat()</tt> function. This function returns the file attributes of a file and does not attempt to open the file. The other alternative way is simply try to open the file and see if this fails.

”’Note”’: In order to use this code, you need to install [http://www.forum.nokia.com/info/sw.nokia.com/id/91d89929-fb8c-4d66-bea0-227e42df9053/Open_C_SDK_Plug-In.html Open C/C++ plug-in].

This snippet can be self-signed.

==MMP file==

The following libraries are required:

<code>
LIBRARY libstdcpp.lib
LIBRARY libc.lib
LIBRARY euser.lib
</code>

<!– ==Header file==
<code cpp>
</code>
–>
==Source file==

<code cpp>

#include <stdio.h> //FILE, fopen(), fclose()
#include <sys/stat.h> //stat, stat()
#include <string> //string
#include <fstream> //fstream
#include <iostream> //cout

using namespace std;

bool OpenCFileExists(const char* filename)
{ FILE* fp = NULL;
//this will fail if more capabilities to read the //contents of the file is required (e.g. \private\…) fp = fopen(filename, “r”); if(fp != NULL) { fclose(fp); return true; } fclose(fp); return false;
}

bool OpenCppFileExists(const string& filename)
{ fstream fin; //this will fail if more capabilities to read the //contents of the file is required (e.g. \private\…) fin.open(filename.c_str(), ios::in); if(fin.is_open()) { fin.close(); return true; } fin.close(); return false;
}

bool FileExists(const char* filename)
{ struct stat info; int ret = -1;
//get the file attributes ret = stat(filename, &info); if(ret == 0) { //stat() is able to get the file attributes, //so the file obviously exists return true; } else { //stat() is not able to get the file attributes, //so the file obviously does not exist or //more capabilities is required return false; }
}
bool FileExists(const string& filename)
{ return FileExists(filename.c_str());
}

//the simple test program for above functions
int main()
{ string filename;
cout << “Enter the filename (empty line quit):” << endl; cout << “>”; while(getline(cin, filename)) { string result; if(filename.size() == 0) break; OpenCFileExists(filename.c_str()) ? result = ” found!” : result = ” not found!”; cout << “OpenCFileExists: ” << filename << result << endl; OpenCppFileExists(filename) ? result = ” found!” : result = ” not found!”; cout << “OpenCppFileExists: ” << filename << result << endl; FileExists(filename) ? result = ” found!” : result = ” not found!”; cout << “FileExists: ” << filename << result << endl; cout << “>”; }

return 0;
}
</code>

==Postconditions==

The test program prompts user to enter filenames and uses example functions to test existence of these files until the empty line is entered and the program ends.

<!– ==See also== –>

ID  
Creation date September 4, 2008

Platform S60 3rd Edition, FP2
Tested on devices Nokia 6220 Classic

Category Open C/C++
Subcategory Files/Data

Keywords (APIs, classes, methods, functions): fstream, stat, FILE, fopen(), fclose(), fstream::open(), fstream::is_open(), fstream::close()

Overview
This code snippet shows how to check if a certain file exists using C or C++. The portable way that works in C and C++, is to check if a file exists with the stat() function. This function returns the file attributes of a file and does not attempt to open the file. The other alternative way is simply try to open the file and see if this fails.
Note: In order to use this code, you need to install Open C/C++ plug-in.
This snippet can be self-signed.

MMP file
The following libraries are required:

LIBRARY libstdcpp.lib
LIBRARY libc.lib
LIBRARY euser.lib
Source file
#include <stdio.h> //FILE, fopen(), fclose()
#include <sys/stat.h> //stat, stat()
#include <string> //string
#include <fstream> //fstream
#include <iostream> //cout
 
using namespace std;
 
bool OpenCFileExists(const char* filename)
{
FILE* fp = NULL;
 
//this will fail if more capabilities to read the
//contents of the file is required (e.g. \private\…)
fp = fopen(filename, "r");

if(fp != NULL)
{
fclose(fp);
return true;
}
fclose(fp);

return false;
}
 
bool OpenCppFileExists(const string& filename)
{
fstream fin;

//this will fail if more capabilities to read the
//contents of the file is required (e.g. \private\…)
fin.open(filename.c_str(), ios::in);

if(fin.is_open())
{
fin.close();
return true;
}
fin.close();

return false;
}
 
bool FileExists(const char* filename)
{
struct stat info;
int ret = -1;
 
//get the file attributes
ret = stat(filename, &info);
if(ret == 0)
{
//stat() is able to get the file attributes,
//so the file obviously exists
return true;
}
else
{
//stat() is not able to get the file attributes,
//so the file obviously does not exist or
//more capabilities is required
return false;
}
}
bool FileExists(const string& filename)
{
return FileExists(filename.c_str());
}
 
//the simple test program for above functions
int main()
{
string filename;
 
cout << "Enter the filename (empty line quit):" << endl;
cout << ">";

while(getline(cin, filename))
{
string result;

if(filename.size() == 0)
break;

OpenCFileExists(filename.c_str()) ?
result = " found!" : result = " not found!";
cout << "OpenCFileExists: " << filename << result << endl;

OpenCppFileExists(filename) ? result = " found!" : result = " not found!";
cout << "OpenCppFileExists: " << filename << result << endl;

FileExists(filename) ? result = " found!" : result = " not found!";
cout << "FileExists: " << filename << result << endl;

cout << ">";
}
 
 
return 0;
 
}

Postconditions
The test program prompts user to enter filenames and uses example functions to test existence of these files until the empty line is entered and the program ends.