12-19-2012
If DIR/* and DIR/.* resolve to DIR/. DIR/.. and DIR/* literally, the first two are ignored and the last is neither dir nor file. No directory is truly empty, . and .. are real entries with real inode numbers. The nullglob part is nice, but is a subshell more costly than a failed directory lookup? As the man page says, nullglob is so unexpected and potentially destabilizing that you always need to restrict it to a subshell.
Last edited by DGPickett; 12-19-2012 at 06:19 PM..
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DIRECTORY(3) Library Functions Manual DIRECTORY(3)
NAME
opendir, readdir, telldir, seekdir, rewinddir, closedir - directory operations
SYNOPSIS
#include <sys/types.h>
#include <sys/dir.h>
DIR *opendir(filename)
char *filename;
struct direct *readdir(dirp)
DIR *dirp;
long telldir(dirp)
DIR *dirp;
seekdir(dirp, loc)
DIR *dirp;
long loc;
rewinddir(dirp)
DIR *dirp;
closedir(dirp)
DIR *dirp;
DESCRIPTION
Opendir opens the directory named by filename and associates a directory stream with it. Opendir returns a pointer to be used to identify
the directory stream in subsequent operations. The pointer NULL is returned if filename cannot be accessed, or if it cannot malloc(3)
enough memory to hold the whole thing.
Readdir returns a pointer to the next directory entry. It returns NULL upon reaching the end of the directory or detecting an invalid
seekdir operation.
Telldir returns the current location associated with the named directory stream.
Seekdir sets the position of the next readdir operation on the directory stream. The new position reverts to the one associated with the
directory stream when the telldir operation was performed. Values returned by telldir are good only for the lifetime of the DIR pointer
from which they are derived. If the directory is closed and then reopened, the telldir value may be invalidated due to undetected direc-
tory compaction. It is safe to use a previous telldir value immediately after a call to opendir and before any calls to readdir.
Rewinddir resets the position of the named directory stream to the beginning of the directory.
Closedir closes the named directory stream and frees the structure associated with the DIR pointer.
Sample code which searchs a directory for entry ``name'' is:
len = strlen(name);
dirp = opendir(".");
for (dp = readdir(dirp); dp != NULL; dp = readdir(dirp))
if (dp->d_namlen == len && !strcmp(dp->d_name, name)) {
closedir(dirp);
return FOUND;
}
closedir(dirp);
return NOT_FOUND;
SEE ALSO
open(2), close(2), read(2), lseek(2), dir(5)
4.2 Berkeley Distribution September 24, 1985 DIRECTORY(3)