HP 3000 Manuals HP 3000 Manuals
readdir
Reads entries from an open directory stream.
Syntax
#include <sys/types.h>
#include <dirent.h>
struct dirent *readdir (DIR *dirp);
Parameters
dirp A pointer to an open directory stream obtained from a
successful call to opendir().
Return Values
<>NULL Success.
NULL End of directory stream was reached, but errno is not
modified.
NULL An error occurred, and errno is set to indicate the error
condition.
Description
The readdir() function returns a pointer to a structure of type dirent
representing the directory entry at the current position in the directory
stream associated with dirp, then positions the directory stream at the
next entry. A NULL pointer is returned upon reaching the end of the
directory stream.
Upon successful completion, readdir() marks for update the st_atime time
field of the directory.
The pointer returned by readdir() points to data that is overwritten by
another call to readdir() on the same directory stream.
Implementation Considerations
Refer to the EFAULT and ESYSERR error descriptions below.
Both the dot and dot dot directory entries are returned only for
directories that explicitly contain them. The root directory, MPE/iX
accounts, and MPE/iX groups do not contain explicit dot and dot dot
entries.
If an entry is removed from or added to the directory after the most
recent call to opendir() or rewinddir(), subsequent returns from
readdir() accurately reflect the current state of the directory.
Errors
If an error occurs, errno is set to one of the following values:
EBADF CAUSE The dirp parameter does not refer to an open
directory stream.
ACTION Pass an open directory stream pointer returned by the
opendir() function.
EFAULT CAUSE The system detected a NULL or bad address in
attempting to use the dirp parameter.
ACTION Make sure that the pointer is correctly initialized.
ESYSERR CAUSE An operating system error has occurred that does not
map directly to any of the above errors.
ACTION Examine the MPE/iX error stack for the type of system
error.
See Also
mkdir(), closedir(), opendir(), rewinddir(), <dirent.h>, POSIX.1 (Section
5.1.2)