telldir (3)
Leading comments
Copyright 1993 David Metcalfe (david@prism.demon.co.uk) %%%LICENSE_START(VERBATIM) Permission is granted to make and distribute verbatim copies of this manual provided the copyright notice and this permission notice are preserved on all copies. Permission is granted to copy and distribute modified versions of this manual under the conditions for verbatim copying, provided that the entire resulting derived work is distributed under the terms of a permission notice identical to this one. Sin...
NAME
telldir - return current location in directory streamSYNOPSIS
#include <dirent.h> long telldir(DIR *dirp);
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
telldir(): _BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE
DESCRIPTION
The telldir() function returns the current location associated with the directory stream dirp.RETURN VALUE
On success, the telldir() function returns the current location in the directory stream. On error, -1 is returned, and errno is set appropriately.ERRORS
- EBADF
- Invalid directory stream descriptor dirp.
ATTRIBUTES
For an explanation of the terms used in this section, see attributes(7).| Interface | Attribute | Value |
| telldir() | Thread safety | MT-Safe |
CONFORMING TO
POSIX.1-2001, POSIX.1-2008, 4.3BSD.NOTES
In glibc up to version 2.1.1, the return type of telldir() was off_t. POSIX.1-2001 specifies long, and this is the type used since glibc 2.1.2.In early filesystems, the value returned by telldir() was a simple file offset within a directory. Modern filesystems use tree or hash structures, rather than flat tables, to represent directories. On such filesystems, the value returned by telldir() (and used internally by readdir(3)) is a "cookie" that is used by the implementation to derive a position within a directory. Application programs should treat this strictly as an opaque value, making no assumptions about its contents.