1TELLDIR(3) Linux Programmer's Manual TELLDIR(3)
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6 telldir - return current location in directory stream
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9 #include <dirent.h>
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11 long telldir(DIR *dirp);
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13 Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
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15 telldir():
16 _XOPEN_SOURCE
17 || /* Glibc since 2.19: */ _DEFAULT_SOURCE
18 || /* Glibc versions <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE
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21 The telldir() function returns the current location associated with the
22 directory stream dirp.
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25 On success, the telldir() function returns the current location in the
26 directory stream. On error, -1 is returned, and errno is set appropri‐
27 ately.
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30 EBADF Invalid directory stream descriptor dirp.
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33 For an explanation of the terms used in this section, see
34 attributes(7).
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36 ┌──────────┬───────────────┬─────────┐
37 │Interface │ Attribute │ Value │
38 ├──────────┼───────────────┼─────────┤
39 │telldir() │ Thread safety │ MT-Safe │
40 └──────────┴───────────────┴─────────┘
42 POSIX.1-2001, POSIX.1-2008, 4.3BSD.
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45 In glibc up to version 2.1.1, the return type of telldir() was off_t.
46 POSIX.1-2001 specifies long, and this is the type used since glibc
47 2.1.2.
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49 In early filesystems, the value returned by telldir() was a simple file
50 offset within a directory. Modern filesystems use tree or hash struc‐
51 tures, rather than flat tables, to represent directories. On such
52 filesystems, the value returned by telldir() (and used internally by
53 readdir(3)) is a "cookie" that is used by the implementation to derive
54 a position within a directory. Application programs should treat this
55 strictly as an opaque value, making no assumptions about its contents.
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58 closedir(3), opendir(3), readdir(3), rewinddir(3), scandir(3),
59 seekdir(3)
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62 This page is part of release 5.04 of the Linux man-pages project. A
63 description of the project, information about reporting bugs, and the
64 latest version of this page, can be found at
65 https://www.kernel.org/doc/man-pages/.
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69 2017-09-15 TELLDIR(3)