-.\" Hey Emacs! This file is -*- nroff -*- source.
-.\"
.\" This manpage is Copyright (C) 1992 Drew Eckhardt;
-.\" 1993 Michael Haardt, Ian Jackson.
+.\" and Copyright (C) 1993 Michael Haardt, Ian Jackson.
+.\" and Copyright (C) 2006, 2014 Michael Kerrisk
.\"
+.\" %%%LICENSE_START(VERBATIM)
.\" Permission is granted to make and distribute verbatim copies of this
.\" manual provided the copyright notice and this permission notice are
.\" preserved on all copies.
.\"
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.\" the source, must acknowledge the copyright and authors of this work.
+.\" %%%LICENSE_END
.\"
.\" Modified 1993-07-24 by Rik Faith
.\" Modified 1996-04-26 by Nick Duffek <nsd@bbc.com>
.\" Modified 1996-11-06 by Eric S. Raymond <esr@thyrsus.com>
.\" Modified 1997-01-31 by Eric S. Raymond <esr@thyrsus.com>
-.\" Modified 2004-06-23 by Michael Kerrisk <mtk-manpages@gmx.net>
+.\" Modified 2004-06-23 by Michael Kerrisk <mtk.manpages@gmail.com>
.\"
-.TH SYMLINK 2 2004-06-23 "Linux" "Linux Programmer's Manual"
+.TH SYMLINK 2 2017-09-15 "Linux" "Linux Programmer's Manual"
.SH NAME
-symlink \- make a new name for a file
+symlink, symlinkat \- make a new name for a file
.SH SYNOPSIS
+.nf
+.B #include <unistd.h>
+.PP
+.BI "int symlink(const char *" target ", const char *" linkpath );
+
+.BR "#include <fcntl.h> " "/* Definition of AT_* constants */"
.B #include <unistd.h>
-.sp
-.BI "int symlink(const char *" oldpath ", const char *" newpath );
+.PP
+.BI "int symlinkat(const char *" target ", int " newdirfd \
+", const char *" linkpath );
+.PP
+.fi
+.in -4n
+Feature Test Macro Requirements for glibc (see
+.BR feature_test_macros (7)):
+.in
+.PP
+.ad l
+.BR symlink ():
+.RS 4
+_XOPEN_SOURCE\ >=\ 500 || _POSIX_C_SOURCE\ >=\ 200112L
+.\" || _XOPEN_SOURCE\ &&\ _XOPEN_SOURCE_EXTENDED
+ || /* Glibc versions <= 2.19: */ _BSD_SOURCE
+.RE
+.PP
+.BR symlinkat ():
+.PD 0
+.ad l
+.RS 4
+.TP 4
+Since glibc 2.10:
+_POSIX_C_SOURCE\ >=\ 200809L
+.TP
+Before glibc 2.10:
+_ATFILE_SOURCE
+.RE
+.ad b
+.PD
.SH DESCRIPTION
.BR symlink ()
creates a symbolic link named
-.I newpath
+.I linkpath
which contains the string
-.IR oldpath .
-
-Symbolic links are interpreted at run-time as if the contents of the
+.IR target .
+.PP
+Symbolic links are interpreted at run time as if the contents of the
link had been substituted into the path being followed to find a file or
directory.
-
+.PP
Symbolic links may contain
.I ..
path components, which (if used at the start of the link) refer to the
parent directories of that in which the link resides.
-
+.PP
A symbolic link (also known as a soft link) may point to an existing
file or to a nonexistent one; the latter case is known as a dangling
link.
-
+.PP
The permissions of a symbolic link are irrelevant; the ownership is
ignored when following the link, but is checked when removal or
renaming of the link is requested and the link is in a directory with
the sticky bit
.RB ( S_ISVTX )
set.
-
+.PP
If
-.I newpath
-exists it will
+.I linkpath
+exists, it will
.I not
be overwritten.
-.SH "RETURN VALUE"
+.SS symlinkat()
+The
+.BR symlinkat ()
+system call operates in exactly the same way as
+.BR symlink (),
+except for the differences described here.
+.PP
+If the pathname given in
+.I linkpath
+is relative, then it is interpreted relative to the directory
+referred to by the file descriptor
+.I newdirfd
+(rather than relative to the current working directory of
+the calling process, as is done by
+.BR symlink ()
+for a relative pathname).
+.PP
+If
+.I linkpath
+is relative and
+.I newdirfd
+is the special value
+.BR AT_FDCWD ,
+then
+.I linkpath
+is interpreted relative to the current working
+directory of the calling process (like
+.BR symlink ()).
+.PP
+If
+.I linkpath
+is absolute, then
+.I newdirfd
+is ignored.
+.SH RETURN VALUE
On success, zero is returned.
On error, \-1 is returned, and
.I errno
.TP
.B EACCES
Write access to the directory containing
-.I newpath
+.I linkpath
is denied, or one of the directories in the path prefix of
-.IR newpath
+.I linkpath
did not allow search permission.
(See also
.BR path_resolution (7).)
.TP
+.B EDQUOT
+The user's quota of resources on the filesystem has been exhausted.
+The resources could be inodes or disk blocks, depending on the filesystem
+implementation.
+.TP
.B EEXIST
-.I newpath
+.I linkpath
already exists.
.TP
.B EFAULT
-.IR oldpath " or " newpath " points outside your accessible address space."
+.IR target " or " linkpath " points outside your accessible address space."
.TP
.B EIO
An I/O error occurred.
.TP
.B ELOOP
Too many symbolic links were encountered in resolving
-.IR newpath .
+.IR linkpath .
.TP
.B ENAMETOOLONG
-.IR oldpath " or " newpath " was too long."
+.IR target " or " linkpath " was too long."
.TP
.B ENOENT
A directory component in
-.I newpath
+.I linkpath
does not exist or is a dangling symbolic link, or
-.I oldpath
-is the empty string.
+.I target
+or
+.I linkpath
+is an empty string.
.TP
.B ENOMEM
Insufficient kernel memory was available.
.TP
.B ENOTDIR
A component used as a directory in
-.IR newpath
+.I linkpath
is not, in fact, a directory.
.TP
.B EPERM
The filesystem containing
-.IR newpath
+.I linkpath
does not support the creation of symbolic links.
.TP
.B EROFS
-.I newpath
+.I linkpath
is on a read-only filesystem.
-.SH "CONFORMING TO"
-SVr4, 4.3BSD, POSIX.1-2001.
+.PP
+The following additional errors can occur for
+.BR symlinkat ():
+.TP
+.B EBADF
+.I newdirfd
+is not a valid file descriptor.
+.TP
+.B ENOENT
+.I linkpath
+is a relative pathname and
+.IR newdirfd
+refers to a directory that has been deleted.
+.TP
+.B ENOTDIR
+.I linkpath
+is relative and
+.I newdirfd
+is a file descriptor referring to a file other than a directory.
+.SH VERSIONS
+.BR symlinkat ()
+was added to Linux in kernel 2.6.16;
+library support was added to glibc in version 2.4.
+.SH CONFORMING TO
+.BR symlink ():
+SVr4, 4.3BSD, POSIX.1-2001, POSIX.1-2008.
.\" SVr4 documents additional error codes EDQUOT and ENOSYS.
.\" See
.\" .BR open (2)
.\" re multiple files with the same name, and NFS.
+.PP
+.BR symlinkat ():
+POSIX.1-2008.
.SH NOTES
No checking of
-.I oldpath
+.I target
is done.
-
-Deleting the name referred to by a symlink will actually delete the
+.PP
+Deleting the name referred to by a symbolic link will actually delete the
file (unless it also has other hard links).
-If this behaviour is not desired, use
+If this behavior is not desired, use
.BR link (2).
-.SH "SEE ALSO"
+.SS Glibc notes
+On older kernels where
+.BR symlinkat ()
+is unavailable, the glibc wrapper function falls back to the use of
+.BR symlink ().
+When
+.I linkpath
+is a relative pathname,
+glibc constructs a pathname based on the symbolic link in
+.IR /proc/self/fd
+that corresponds to the
+.IR newdirfd
+argument.
+.SH SEE ALSO
.BR ln (1),
+.BR namei (1),
+.BR lchown (2),
.BR link (2),
.BR lstat (2),
.BR open (2),
.BR readlink (2),
.BR rename (2),
-.BR symlinkat (2),
-.BR unlink (2)
-.BR path_resolution (7)
+.BR unlink (2),
+.BR path_resolution (7),
+.BR symlink (7)
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