check existence of file in C++

[meixiang6]

#include #include #include #include #include // getcwd() definition #include // MAXPATHLEN definition using namespace std; int main() { string database; cout << "Select full path of Database" << endl; cin >> database; How do I check the existence of a file in C++? In perl it would be something like: if (!database){ print "No database found\n"; exit; } I tried looking online for hours but all the suggestions didnt work so far.. Thanks in advance!

[Iain Clarke Warrior Programmer]

do a seatch for PathFileExists. Iain.

Codeproject MVP for C++, I can't believe it's for my lounge posts...

[meixiang6]

PathFileExists is a windows API and I am running C++ in linux so it doesnt work as far as I know and have been trying unless I goofed up...

[enhzflep]

I think you should be able to use _findfirst and _findnext on 'nix, I can't remember. They're in io.h Or you could try to open the file and look at the function result....

[meixiang6]

After a lot of wrong examples from googling the web, I finally find something that works: myFileName = file; inp.open(myFileName.c_str(), ifstream::in); inp.close(); if(inp.fail()) { inp.clear(ios::failbit); cout << "No File found " << myFileName.c_str() << endl; exit(5); } else { cout << "Found File" << myFileName.c_str() << endl; } Thanks, hope this might help someone else... Bye the way is this board only for Visual C++ or can someone working on Linux with C++ ask Qs?

[David Crow]

meixiang6 wrote:

...I am running C++ in linux...

It helps to mention this little requirement up front.

"Old age is like a bank account. You withdraw later in life what you have deposited along the way." - Unknown

"Fireproof doesn't mean the fire will never come. It means when the fire comes that you will be able to withstand it." - Michael Simmons

[David Crow]

meixiang6 wrote:

How do I check the existence of a file in C++?

It's not C++, but you can use _access().

"Old age is like a bank account. You withdraw later in life what you have deposited along the way." - Unknown

"Fireproof doesn't mean the fire will never come. It means when the fire comes that you will be able to withstand it." - Michael Simmons

[Rajesh R Subramanian]

meixiang6 wrote:

Bye the way is this board only for Visual C++ or can someone working on Linux with C++ ask Qs?

We pretty much assume Visual C++ here, mostly even MFC is assumed to be used. Just in case you hadn't noticed the name of this board, it is MFC/C++. You can ask C++ on Unix/Linux questions here, but you must let us know of it when posting your question.

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

[Stuart Dootson]

The standard way of checking file existence on *nix (it works on Windows as well) is stat or fstat[^], I believe.

Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p

[uzziah0]

or FindFirstFile()

[meixiang6]

I will give it a try tommorrow...thanks!

[Dan 0]

You can also try in Windows,

if ( 0 == _access( database.c_str(), 0 ) ) {
cout<<"No database found.\n"
}

and the nix equivelant is

if ( 0 == access( database.c_str(), 0 ) ) {
cout<<"No database found.\n"
}