Check for file existance...

This is a discussion on Check for file existance... within the C++ Programming forums, part of the General Programming Boards category; Hey guys, Just need a quick little bit of help. How do you check if a file exists or not? ...

  1. #1
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    Check for file existance...

    Hey guys, Just need a quick little bit of help. How do you check if a file exists or not? I tried this...

    Code:
    ...
    if(ifstream ("filename")==0)
    {
         cout<<"File Exists!";
    }
    ...
    it didn't work.

    Thanks guys

  2. #2
    People Love Me
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    I believe it works like this:
    Code:
    ifstream myFile("Something.txt");
    
    if (!myFile){
    cout << "\n Failed to open file.";}
    
    else{
    cout << "\n Success.";}

  3. #3
    Registered User
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    Or you can use is_open().
    Code:
    ifstream myFile("filename");
    if(myFile.is_open())
    {
         cout<<"File Exists!";
    }

  4. #4
    Cat without Hat CornedBee's Avatar
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    Or the exists() call from the CRT, which doesn't care if you actually have read permission on the file.
    All the buzzt!
    CornedBee

    "There is not now, nor has there ever been, nor will there ever be, any programming language in which it is the least bit difficult to write bad code."
    - Flon's Law

  5. #5
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    or if you are using windows you can use PathFileExists()

  6. #6
    Banned
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    I had some problems using PathFileExists();
    Code:
    #include <iostream>
    #include <windows.h>
    using namespace std;
    int main()
    {
    	if (PathFileExists("Data.txt") == 0)
    	{
    		cout << "File Found "<<endl;
    	}
    	else
    	{
    		cout << "File Not Found " <<endl;
    	}
    	cin.get();
    }
    What header file is this declared in?

  7. #7
    erstwhile
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    Everything you ever wanted to know about PathFileExists, but were afraid to ask.
    CProgramming FAQ
    Caution: this person may be a carrier of the misinformation virus.

  8. #8
    ATH0 quzah's Avatar
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    Quote Originally Posted by Ken Fitlike
    Everything you ever wanted to know about PathFileExists, but were afraid to ask.
    What you meant to say was:

    Everything you ever wanted to know about PathFileExists, but were too ........ing lazy to search for!

    Quzah.
    Hope is the first step on the road to disappointment.

  9. #9
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    Code:
    #include <iostream>
    #include <windows.h>
    #include <shlwapi.h>
    
    #pragma comment(lib,"shlwapi.lib")
    
    using namespace std;
    
    int main()
    {
    	int A = PathFileExists("data.txt");
    
        if (A == 1)
        {
            cout << "File Found "<<endl;
        }
        else
        {
            cout << "File Not Found " <<endl;
        }
        cin.get();
    	return 0;
    }

  10. #10
    Handy Andy andyhunter's Avatar
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    Careful, I believe
    #pragma comment(lib,"shlwapi.lib")
    is compiler specific and will not work in all cases.

    *edit - oops didn't mean to bump the thread. I didn't realize it was so old. *
    i don't think most standard compilers support programmers with more than 4 red boxes - Misplaced

    It is my sacred duity to stand in the path of the flood of ignorance and blatant stupidity... - quzah

    Such pointless tricks ceased to be interesting or useful when we came down from the trees and started using higher level languages. - Salem

  11. #11
    Cat without Hat CornedBee's Avatar
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    Thread wasn't old.

    This pragma is indeed compiler-specific. But then, PathFileExists is itself platform-specific.
    All the buzzt!
    CornedBee

    "There is not now, nor has there ever been, nor will there ever be, any programming language in which it is the least bit difficult to write bad code."
    - Flon's Law

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