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How to get the current working directory

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Join Date: Aug 2007

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tonyaim83

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How to get the current working directory

Jan 9th, 2008

Hi
What is require is to get the path of current working directory.I m working on windows-XP.
Is any function avaliable in c/c++ i could find on net
#include <unistd.h>
char *getcwd(char *buf, size_t size);

But not working i don't know why. Can u provide small code of how to use this function or any other function which can do the above task in a better way.

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niek_e

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Re: How to get the current working directory

Jan 9th, 2008

> But not working..

What is not working? How did you use the command?

> Can U provide small code...

Yup, it took me about 10 seconds on google

regards Niek

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Ancient Dragon Ancient Dragon is offline

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Re: How to get the current working directory

Jan 9th, 2008

Microsoft compilers do not use unistd.h -- that's for *nix. And Microsoft put an underscore in front of the name, so its _getcwd().. The link contains example code too.

Don't PM me with questions -- you might get a nasty PM in response. If you have a question then post it in one of the forums.

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tonyaim83

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Re: How to get the current working directory

Jan 9th, 2008

Ok my first problem is solved now my code is

 Help with Code Tags 
 c++ Syntax (Toggle Plain Text) 
char *path=NULL;
size_t size;
path=getcwd(path,size);
cout<<"\n current Path"<<path;
char *path=NULL;
size_t size;
path=getcwd(path,size);
cout<<"\n current Path"<<path;

This is working fine. Now what i want is to add string to this path. Say currently path is C:\MyProject. Now i want to add \default.txt to the value of path so that it become C:\MyProject\default.txt . As this function returns a char * i'm not able to do this. Kindly help.

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niek_e

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Re: How to get the current working directory

Jan 9th, 2008

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Originally Posted by Ancient Dragon

Microsoft compilers do not use unistd.h -- that's for *nix. And Microsoft put an underscore in front of the name, so its _getcwd().. The link contains example code too.

Hmm, I've tried the code on my Windows Machine with VC2005 and it compiles fine ? Not even warnings or whatever..

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Re: How to get the current working directory

Jan 9th, 2008

use setenv(), but it only works for the current process. When that process ends the new environment variable is reset back to its original state. The only way to make it permanent in the system is to change it via control panel.

Don't PM me with questions -- you might get a nasty PM in response. If you have a question then post it in one of the forums.

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niek_e

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Re: How to get the current working directory

Jan 9th, 2008

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Originally Posted by tonyaim83

Now what i want is to add string to this path.

You could use a stringstream to add a string to a char[]. It would look something like this (untested):

 Help with Code Tags 
 c Syntax (Toggle Plain Text) 
#include <sstream>
#include <iostream>
 
using namespace std;
 
int main(void)
 
{
  char path[] = "c:\\test\\";
  string file = "default.txt";
 
  stringstream complete;
  complete << path << file;
  cout << complete.str() << endl; 
  cin.get();
  return 0;
}
#include <sstream>
#include <iostream>

using namespace std;

int main(void)

{
  char path[] = "c:\\test\\";
  string file = "default.txt";

  stringstream complete;
  complete << path << file;
  cout << complete.str() << endl; 
  cin.get();
  return 0;
}

There are alot of other ways to do this.

-Niek

Last edited by niek_e; Jan 9th, 2008 at 7:02 am.

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Jonny D

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Re: How to get the current working directory

Dec 6th, 2008

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Originally Posted by tonyaim83

Ok my first problem is solved now my code is
Help with Code Tags

c++ Syntax (Toggle Plain Text)
char *path=NULL;
size_t size;
path=getcwd(path,size);
cout<<"\n current Path"<<path;
char *path=NULL; size_t size; path=getcwd(path,size); cout<<"\n current Path"<<path;
This is working fine. Now what i want is to add string to this path. Say currently path is C:\MyProject. Now i want to add \default.txt to the value of path so that it become C:\MyProject\default.txt . As this function returns a char * i'm not able to do this. Kindly help.

Just to clear things up for future readers...

 Help with Code Tags 
 C++ Syntax (Toggle Plain Text) 
#include <unistd.h>  // getcwd() definition
#include <sys/param.h>  // MAXPATHLEN definition
 
int main(int argc, char* argv[])  // Always write main() this way!
{<blockquote>// Here's a way to use getcwd()
char path1[MAXPATHLEN];  // This is a buffer for the text
getcwd(path1, MAXPATHLEN);
 
// The return value is redundant, but can be useful.
 
// And here's one way to get to your program's path.
// This is sometimes not the initial cwd, and this may not work
// portably (because Windows uses '\\' and Linux uses '/').
string path2 = argv[0];  /* Copy the first command-line argument,
         which is the execution line of the program */
path2 = path2.substr(0, path2.find_last_of('/'));  // Remove app name from string
 
// Now, if you want to do more stuff...
char file1[MAXPATHLEN];
strcpy(file1, path1);
strcat(file1, "/default.txt");
// or...
string file2 = path2;
file2 += "/default.txt";
 
return 0;</blockquote>}
#include <unistd.h>  // getcwd() definition
#include <sys/param.h>  // MAXPATHLEN definition

int main(int argc, char* argv[])  // Always write main() this way!
{<blockquote>// Here's a way to use getcwd()
char path1[MAXPATHLEN];  // This is a buffer for the text
getcwd(path1, MAXPATHLEN);

// The return value is redundant, but can be useful.

// And here's one way to get to your program's path.
// This is sometimes not the initial cwd, and this may not work
// portably (because Windows uses '\\' and Linux uses '/').
string path2 = argv[0];  /* Copy the first command-line argument,
         which is the execution line of the program */
path2 = path2.substr(0, path2.find_last_of('/'));  // Remove app name from string

// Now, if you want to do more stuff...
char file1[MAXPATHLEN];
strcpy(file1, path1);
strcat(file1, "/default.txt");
// or...
string file2 = path2;
file2 += "/default.txt";

return 0;</blockquote>}

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ArkM

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Re: How to get the current working directory

Dec 6th, 2008

Some remarks to the previous post:
1. Alas, argv[0] IS NOT a path of exe module.
The C standard (5.1.2.2.1 Program Startup):

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If the value of argc is greater than zero, the string pointed to by argv[0] represents the program name; argv[0][0] shall be the null character if the program name is not available from the host environment.

The program name is not the same thing as an exe path!
2. The exe directory does not bear a relation to the current working directory...
3. No platform-independent methods to get the current working directory. The getcwd function is not C and C++ standard library function...

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Jonny D

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Re: How to get the current working directory

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Dec 7th, 2008

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Originally Posted by ArkM

Some remarks to the previous post:
1. Alas, argv[0] IS NOT a path of exe module.
The C standard (5.1.2.2.1 Program Startup):

The program name is not the same thing as an exe path!
2. The exe directory does not bear a relation to the current working directory...
3. No platform-independent methods to get the current working directory. The getcwd function is not C and C++ standard library function...

"If the value of argc is greater than zero, the array members argv[0] through argv[argc-1] inclusive shall contain pointers to strings, which are given implementation-defined values by the host environment prior to program startup. "

Is your reference the c0x standard? It's not even implemented yet... It's called the c0x standard because it is meant to be released some year this decade (now it must be 2009). For most people, portability between Windows, MacOS, and Linux are enough. On those OSes, getcwd() works and argv[0] works (at least with GCC) to give you the full command line call to your executable. Don't argue until you try the above code... What else is the "program name" except what the OS sees (i.e. what it needs to know in order to run your program)? You'll be hard-pressed to find a counter-example to this functionality, though I welcome one.