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TELLDIR(3)                 Linux Programmer's Manual                TELLDIR(3)
NAME
       telldir - return current location in directory stream
SYNOPSIS
       #include <dirent.h>
       long telldir(DIR *dirp);
   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
       telldir():
        _XOPEN_SOURCE
           || /* Glibc since 2.19: */ _DEFAULT_SOURCE
           || /* Glibc versions <= 2.19: */ _BSD_SOURCE || _SVID_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 appropri-
       ately.
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  struc-
       tures,  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.
SEE ALSO
       closedir(3),    opendir(3),   readdir(3),   rewinddir(3),   scandir(3),
       seekdir(3)
COLOPHON
       This page is part of release 4.15 of the Linux  man-pages  project.   A
       description  of  the project, information about reporting bugs, and the
       latest    version    of    this    page,    can     be     found     at
       https://www.kernel.org/doc/man-pages/.
                                  2017-09-15                        TELLDIR(3)