strcmp and some problems I have [strange ones]

zeppelin · 04-03-2004, 03:44 PM

hello I'm trying some low-level stuff:

Code:

while( (dirent_ptr = readdir(dir_ptr)) != NULL )
	{
		//printf("i-node: %ld - ", dirent_ptr->d_ino);
		//printf("filename: %s\n", dirent_ptr->d_name);
		
		if ( stat(dirent_ptr->d_name, &boo_buf) < 0 )
		{
			perror(dirent_ptr->d_name);
			exit(1);
		}

// OK till here


		// result SHOULD  be 0, if file matches with . [but it IS NOT!!] :(
		int result;
                printf("%s\n",dirent_ptr->d_name);
		result = strcmp(dirent_ptr->d_name, ".") ;
                printf("%i\n",result);

eventhough dirent_ptr->d_name is in the beginning . result DOES NOT become 0
if I have ".." then it becomes 0 [in the second time of the loop]

so I guess the strcmp doesn't like the "."??
I tried '.' GCC doesn't like it now!

anyhelp is HIGHLY appreciated.

thx in advance

leonscape · 04-03-2004, 04:12 PM

So your output is

.
1
..
0

Correct?

zeppelin · 04-03-2004, 04:13 PM

yes. irritating hah?

I'm forced to write in C. Oh boy! in C# one could just write != , ==
well I know the Power of C in the low-level, that's why I want your help in this [and not only] but this is the basic to continue :P

leonscape · 04-03-2004, 04:24 PM

c#? don't swear at me

C++ does have a string class as well you know.

printf("dirent_ptr->d_name");

shouldn't that be

printf( "%s", dirent_ptr->d_name );

zeppelin · 04-03-2004, 04:25 PM

oh yes. the code has some addition to make it easy to understand and to help!
plz propose me a solution. I know it's %s :P
I also know that C++ does the trick.
a C only solution would rock

leonscape · 04-03-2004, 04:31 PM

Try '.' instead of "."

or a simple array check

Code:

if ( dirent_ptr->d_name[0] == '.' && dirent_ptr->d_name[1] == '\0' )
   result = 0;
else
   result = 1;

This is probably better and quicker than calling a function.

zeppelin · 04-03-2004, 04:53 PM

oh well you're right. strcmp doesn't do the thing with "." nor with '.'
well I should check just the array then as you say. thanks

this is the best :P [damn to that strcmp]

Code:

if ( dirent_ptr->d_name[0] == '.' || dirent_ptr->d_name == ".." )
			result = 0;
		else
			result = 1;

thanks for your quick help

leonscape · 04-03-2004, 05:00 PM

It is strange that strcmp is returning 1 on "." but 0 on ".." I have tried it hear and it is the other way around, something weird going on in your setup

To be honest I'm not sure that code will work. dirent_ptr->d_name == ".." your comparing the pointer to a constant array. Theres also stuff that could start .thishere as well.

zeppelin · 04-03-2004, 06:02 PM

d_name is a character array IIRC

anyways, the point is that now it's working as expected, and the problem is afterwards [should write an algorithm that will check for the files in a dir, and check some of those files are Dirs, and if they are it should open them etc.. go deep in a recurvise implementation..]

or I could try reading the code in GNU cp

the cp -a
i believe should be fine :P