opendir() + customly created directories

Applications Programming
1

Gday all

In a program I am designing, I am using opendir() to test whether entries under a certain directory are sub-directories or not. This method works fine for the directory itself (.) and the parent directory (..), however it does not work for any sub-directories I manually create.

i.e. it does not work for current_directory/my_sub_directory

I am performing the test in the following manner

if( (sub_dir = opendir(sub_dir_name)) != NULL)
{
       /* Do whatever*/

}

Is there anything I am failing to understand or am I missing out on anything ?

regards
James

2

One trap I always keep falling into is forgetting to glue back the entry from a readdir to the directory I read it from, i.e. using a relative file name in the wrong (e.g. grandparent) directory.

3

I tried this and unfortunately had no luck :frowning:

4

Doubly linked lists..yay.

5

hey all

Ive discovered a better way to test for the presence of sub-directories within folders, however it does not involve the use of opendir()

What I did instead was the following


/*Check if it is current or parent directory*/

if( (strcmp(subfolder_name,".") != 0) &&  (strcmp(subfolder_name,"..") != 0)
{
        /*Check to see if it is a directory by using strrchr()*/

        ptr = strrchr(subfolder_name,'.');

        /*If  strrchr() returns NULL, the current entry
           is indeed a sub-folder*/
  
        if(ptr == NULL)
        {
             /*Do necessary stuff here*/
        }  

}
6

opendir() returns a pointer to a dir stream. readdir() is invoked in a loop afterwards to read the contents of the opened dir stream. Each dir entry is passed from readdir() to stat() which stores information in a stat structure. The S_ISDIR() macro can be used to test whether the stat structure is a dir or not. Look at the manpages of opendir() readdir() and stat().