telldir(3) [x11r4 man page]

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 appro-
       priately.

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.

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)

Check Out this Related Man Page

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

NAME

       dirfd - get directory stream file descriptor

SYNOPSIS

       #include <sys/types.h>
       #include <dirent.h>

       int dirfd(DIR *dirp);

   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

       dirfd():
	   /* Since glibc 2.10: */ _POSIX_C_SOURCE >= 200809L
	       || /* Glibc versions <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE

DESCRIPTION

       The function dirfd() returns the file descriptor associated with the directory stream dirp.

       This  file descriptor is the one used internally by the directory stream.  As a result, it is useful only for functions which do not depend
       on or alter the file position, such as fstat(2) and fchdir(2).  It will be automatically closed when closedir(3) is called.

RETURN VALUE

       On success, a nonnegative file descriptor is returned.  On error, -1 is returned, and errno is set to indicate the cause of the error.

ERRORS

       POSIX.1-2008 specifies two errors, neither of which is returned by the current implementation.

       EINVAL dirp does not refer to a valid directory stream.

       ENOTSUP
	      The implementation does not support the association of a file descriptor with a directory.

ATTRIBUTES

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

       +----------+---------------+---------+
       |Interface | Attribute	  | Value   |
       +----------+---------------+---------+
       |dirfd()   | Thread safety | MT-Safe |
       +----------+---------------+---------+
CONFORMING TO

       POSIX.1-2008.  This function was a BSD extension, present in 4.3BSD-Reno, not in 4.2BSD.

SEE ALSO

       open(2), closedir(3), opendir(3), readdir(3), rewinddir(3), scandir(3), seekdir(3), telldir(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/.

Linux								    2016-03-15								  DIRFD(3)

Linux and UNIX Man Pages

telldir(3) [x11r4 man page]

Check Out this Related Man Page