1LINKAT(2) Linux Programmer's Manual LINKAT(2)
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6 linkat - create a file link relative to directory file descriptors
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9 #include <fcntl.h> /* Definition of AT_* constants */
10 #include <unistd.h>
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12 int linkat(int olddirfd, const char *oldpath,
13 int newdirfd, const char *newpath, int flags);
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15 Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
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17 linkat():
18 Since glibc 2.10: _XOPEN_SOURCE >= 700 || _POSIX_C_SOURCE >= 200809L
19 Before glibc 2.10: _ATFILE_SOURCE
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22 The linkat() system call operates in exactly the same way as link(2),
23 except for the differences described in this manual page.
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25 If the pathname given in oldpath is relative, then it is interpreted
26 relative to the directory referred to by the file descriptor olddirfd
27 (rather than relative to the current working directory of the calling
28 process, as is done by link(2) for a relative pathname).
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30 If oldpath is relative and olddirfd is the special value AT_FDCWD, then
31 oldpath is interpreted relative to the current working directory of the
32 calling process (like link(2)).
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34 If oldpath is absolute, then olddirfd is ignored.
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36 The interpretation of newpath is as for oldpath, except that a relative
37 pathname is interpreted relative to the directory referred to by the
38 file descriptor newdirfd.
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40 By default, linkat(), does not dereference oldpath if it is a symbolic
41 link (like link(2)). Since Linux 2.6.18, the flag AT_SYMLINK_FOLLOW
42 can be specified in flags to cause oldpath to be dereferenced if it is
43 a symbolic link. Before kernel 2.6.18, the flags argument was unused,
44 and had to be specified as 0.
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47 On success, linkat() returns 0. On error, -1 is returned and errno is
48 set to indicate the error.
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51 The same errors that occur for link(2) can also occur for linkat().
52 The following additional errors can occur for linkat():
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54 EBADF olddirfd or newdirfd is not a valid file descriptor.
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56 ENOTDIR
57 oldpath is relative and olddirfd is a file descriptor referring
58 to a file other than a directory; or similar for newpath and
59 newdirfd
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62 linkat() was added to Linux in kernel 2.6.16.
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65 POSIX.1-2008.
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68 See openat(2) for an explanation of the need for linkat().
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71 link(2), openat(2), path_resolution(7), symlink(7)
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74 This page is part of release 3.25 of the Linux man-pages project. A
75 description of the project, and information about reporting bugs, can
76 be found at http://www.kernel.org/doc/man-pages/.
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80Linux 2009-12-13 LINKAT(2)