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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)

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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)
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