telldir(3) — Linux manual page

NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | ATTRIBUTES | CONFORMING TO | NOTES | SEE ALSO | COLOPHON

TELLDIR(3)              Linux Programmer's Manual             TELLDIR(3)

NAME         top

       telldir - return current location in directory stream

SYNOPSIS         top

       #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         top

       The telldir() function returns the current location associated
       with the directory stream dirp.

RETURN VALUE         top

       On success, the telldir() function returns the current location
       in the directory stream.  On error, -1 is returned, and errno is
       set appropriately.

ERRORS         top

       EBADF  Invalid directory stream descriptor dirp.

ATTRIBUTES         top

       For an explanation of the terms used in this section, see
       attributes(7).

       ┌──────────┬───────────────┬─────────┐
       │Interface Attribute     Value   │
       ├──────────┼───────────────┼─────────┤
       │telldir() │ Thread safety │ MT-Safe │
       └──────────┴───────────────┴─────────┘

CONFORMING TO         top

       POSIX.1-2001, POSIX.1-2008, 4.3BSD.

NOTES         top

       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.

SEE ALSO         top

       closedir(3), opendir(3), readdir(3), rewinddir(3), scandir(3),
       seekdir(3)

COLOPHON         top

       This page is part of release 5.10 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)

Pages that refer to this page: closedir(3)dirfd(3)opendir(3)readdir(3)rewinddir(3)scandir(3)seekdir(3)