1READLINKAT(2)              Linux Programmer's Manual             READLINKAT(2)
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NAME

6       readlinkat - read value of a symbolic link relative to a directory file
7       descriptor
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SYNOPSIS

10       #include <fcntl.h> /* Definition of AT_* constants */
11       #include <unistd.h>
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13       int readlinkat(int dirfd, const char *pathname,
14                      char *buf, size_t bufsiz);
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16   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
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18       readlinkat():
19       Since glibc 2.10: _XOPEN_SOURCE >= 700 || _POSIX_C_SOURCE >= 200809L
20       Before glibc 2.10: _ATFILE_SOURCE
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DESCRIPTION

23       The readlinkat() system call operates in exactly the same way as  read‐
24       link(2), except for the differences described in this manual page.
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26       If  the  pathname given in pathname is relative, then it is interpreted
27       relative to the directory referred to  by  the  file  descriptor  dirfd
28       (rather  than  relative to the current working directory of the calling
29       process, as is done by readlink(2) for a relative pathname).
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31       If pathname is relative and dirfd is the special value  AT_FDCWD,  then
32       pathname  is  interpreted  relative to the current working directory of
33       the calling process (like readlink(2)).
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35       If pathname is absolute, then dirfd is ignored.
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RETURN VALUE

38       On success, readlinkat() returns the number of bytes placed in buf.  On
39       error, -1 is returned and errno is set to indicate the error.
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ERRORS

42       The  same  errors  that  occur for readlink(2) can also occur for read‐
43       linkat().  The following additional errors can occur for readlinkat():
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45       EBADF  dirfd is not a valid file descriptor.
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47       ENOTDIR
48              pathname is relative and dirfd is a file descriptor referring to
49              a file other than a directory.
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VERSIONS

52       readlinkat() was added to Linux in kernel 2.6.16.
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CONFORMING TO

55       POSIX.1-2008.
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NOTES

58       See openat(2) for an explanation of the need for readlinkat().
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SEE ALSO

61       openat(2), readlink(2), path_resolution(7)
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COLOPHON

64       This  page  is  part of release 3.25 of the Linux man-pages project.  A
65       description of the project, and information about reporting  bugs,  can
66       be found at http://www.kernel.org/doc/man-pages/.
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70Linux                             2009-12-13                     READLINKAT(2)
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