telldir(3POSIX)

NAME | SYNOPSIS | API RESTRICTIONS | FEATURES | DESCRIPTION | ATTRIBUTES | SEE ALSO | RESTRICTIONS

NAME

directory, opendir, readdir, telldir, seekdir, rewinddir, closedir- directory operations

SYNOPSIS

$(OS_DIR)/lib/libc.a
#include <sys/types.h>
#include <dirent.h>

DIR * opendir(const char * filename);
struct dirent * readdir(DIR * dirp);
long telldir(const DIR * dirp);
void seekdir(DIR * dirp, long loc);
void rewinddir(DIR * dirp);
int closedir(DIR * dirp);

API RESTRICTIONS

The function or functions documented here may not be used safely in all application contexts with all APIs provided in the ChorusOS 5.0 product.

See API(5FEA) for details.

FEATURES

MSDOSFS, NFS_CLIENT, UFS

DESCRIPTION

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 allocate enough memory to hold the whole directory stream (see the malloc(3STDC) man page.

The readdir() function returns a pointer to the next directory entry. It returns NULL on 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;

ATTRIBUTES

See attributes(5) for descriptions of the following attributes:

ATTRIBUTE TYPE	ATTRIBUTE VALUE
Interface Stability	Evolving

SEE ALSO

open(2POSIX) , close(2POSIX) , read(2POSIX) , lseek(2POSIX)

RESTRICTIONS

These library calls do not support multi-threaded applications.

NAME | SYNOPSIS | API RESTRICTIONS | FEATURES | DESCRIPTION | ATTRIBUTES | SEE ALSO | RESTRICTIONS