NAME | SYNOPSIS | FEATURES | DESCRIPTION | ATTRIBUTES | SEE ALSO | HISTORY | RESTRICTIONS
#include <sys/types.h> #include <dirent.h>DIR * opendir(const char * filename);
MSDOSFS, NFS_CLIENT, UFS
The opendir function opens the directory named by filename , associates a directory stream with it and returns a pointer to be used to identify the directory stream in subsequent operations. The NULL pointer is returned if filename cannot be accessed, or if it cannot malloc(3STDC) enough memory to hold all of it.
The readdir function returns a pointer to the next directory entry. It returns NULL upon reaching the end of the directory or detecting an invalid seekdir operation.
The telldir function returns the current location associated with the named directory stream.
The seekdir function 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 valid only for the lifetime of the DIR pointer, dirp , from which they are derived. If the directory is closed and then reopened, the telldir value may be invalidated due to undetected directory compaction. It is safe to use a previous telldir value immediately after a call to opendir and before any calls to readdir .
The rewinddir function resets the position of the named directory stream to the beginning of the directory.
The closedir function closes the named directory stream and frees the structure associated with the dirp pointer, returning 0 on success. On failure, -1 is returned and the global variable errno is set to indicate the error.
Sample code which searches a directory for the ``name'' entry is:
len = strlen(name); dirp = opendir("."); if (dirp) { while ((dp = readdir(dirp)) != NULL) if (dp->d_namlen == len && !strcmp(dp->d_name, name)) { (void) closedir(dirp); return FOUND; } (void) closedir(dirp); } return NOT_FOUND;
See attributes(5) for descriptions of the following attributes:
ATTRIBUTE TYPE | ATTRIBUTE VALUE |
---|---|
Interface Stability | Evolving |
The opendir, readdir, telldir, seekdir, rewinddir and closedir functions appeared in 4.2 BSD.
These library calls do not support multi-threaded applications.
NAME | SYNOPSIS | FEATURES | DESCRIPTION | ATTRIBUTES | SEE ALSO | HISTORY | RESTRICTIONS