How to understand chdir function?

xeon123 · 10-15-2007, 04:05 PM

Hi, I'm trying to do a small C program that changes the current directory.

Code:

#include <unistd.h>

char *directory = ".";

void changedir()
{
  directory = "/tmp";

  if (chdir(directory) != 0)
    perror("chdir() to %s failed\n", directory);

  printf("%s\n", directory);
}

int main()
{
  changedir();
}

The problem is that, I don't know what to do with the variable directory.
Ie, if I want to first, change directory and them do an ls of the new directory ( I know that I don't have the ls part here), I must do an ls with the directory value has an argument?

Ex:

Code:

...
execl("ls", directory, (char *) 0);
...

I must keep the value of the directory?

Thanks,
Pedro

duenez · 10-15-2007, 05:53 PM

First of all, have you noticed that the original value of directory (".") is lost when you reassign it to "/tmp"?

Second, after calling chdir, every command will be executed as if it were performed in that directory until the program exits. So no need to keep the directory name in a string.