Read a directory and get stat information
#include <sys/types.h>
#include <dirent.h>
int _readdir_r( DIR *dirp,
struct dirent *entry,
struct dirent **result,
unsigned bufsize );
libc
Use the -l c option to qcc to link against this library. This library is usually included automatically.
The _readdir_r() function is similar to readdir_r(), but provides extra stat() information.
The _readdir_r() function initializes the dirent structure referenced by entry with the directory entry at the current position in the directory stream referred to by dirp, stores a pointer to this structure in *result, and positions the directory stream at the next entry. If you've reached the end of the directory stream, this function sets *result to NULL.
The storage pointed to by entry must be large enough for a dirent or dirent64 structure with the d_name member an array of char containing at least NAME_MAX plus one element. The struct dirent and struct dirent64 structures don't include space for the pathname; you must provide it. For example:
struct dirent *entry; entry = malloc( offsetof(struct dirent, d_name) + NAME_MAX + 1 );
Some filesystems support names that are longer than the value of NAME_MAX. You can use pathconf() with _PC_NAME_MAX to determine the maximum number of bytes (not including the terminating null) allowed in a file name for a particular filesystem.
The buffer can also include space for the additional information; the function copies as much stat() information as will fit in the buffer. The dirent_extra_stat information follows the path, at an 8-byte aligned offset from the start of the dirent structure. The size of the buffer should then be:
len = ((offsetof(struct dirent64, d_name) + pathconf(dirname, _PC_NAME_MAX) + 1 + 7) & ~7U)
+ sizeof(struct dirent_extra_stat);
For information about the dirent_extra_stat structure, see the entry for readdir()
| Safety: | |
|---|---|
| Cancellation point | Yes |
| Interrupt handler | No |
| Signal handler | Yes |
| Thread | Yes |