Program cannot open file, but the file is already there

问题

I am writing a program that will open an image file, but strange thing happened. This is the output from cmd:

C:\Users\Karl\Pictures>testcvconsole mypic.jpg
argv[0]==testcvconsole
argv[1]==mypic.jpg
fopen is null
strerror(errno)==No such file or directory

Are there something I should consider when fopen simply failed to open my file when the file is right there along side with the executable file in the same directory?

This is on Windows 7, Visual Studios Express 2010. C++.

EDIT: code below

#include "stdafx.h"
#include <string.h>
#include <errno.h>

int goMain(int argc, char** argv);

int _tmain(int argc, _TCHAR* argv[])
{
 goMain(argc, (char**)argv);
 return 0;
}

int goMain( int argc, char** argv ){

 if (argv[1] != NULL){
  printf("argv[0]==%S\nargv[1]==%S\n", argv[0], argv[1]);

  if (fopen(argv[1], "r") == NULL){
   printf("fopen is null\n");
   printf(strerror(errno));
  }

 }

 return 0;
}

EDIT2:

I have tried

char *workingDir =_getcwd(NULL, 0);
printf("workingDir == %S", workingDir);

as TomK has suggested and it returned:

workingDir ==

Nothing at all. Hmm...

EDIT3: I am getting something. I tried

argv[1] = "C:/Users/Karl/Pictures/mypic.jpg";

And fopen can open it. This statement above is inserted right before the fopen.

回答1:

Make absolutely sure they are in the same directory. I'm saying this because you're using Visual Studio, for which the "same" directory isn't always so clear, because it depends on how you execute the executable through the IDE.

C:\Users\Karl\Pictures>testcvconsole mypic.jpg

Are you sure mypic.jpg is located in C:\Users\Karl\Pictures ?

回答2:

Can u check whether the working directory is correct?

#include <direct.h>

char *workingDir =_getcwd(NULL, 0);

Can you run your application with admin privileges?

回答3:

Usually the .exe is created in sub-directory either Debug or Release - try giving the absolute path to the image ...

回答4:

I've had this problem, and it turned out that Visual Studio's runtime wasn't setting the current directory. I never figured out the problem: instead I simply used an absolute path. Without the absolute path, your program is looking in C:\. You can also try using ".\\mypic.jpg" or GetCurrentDirectory().

来源：https://stackoverflow.com/questions/4720936/program-cannot-open-file-but-the-file-is-already-there

标签

c++

visual-studio-2010

file

fopen