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fea681da | 1 | .\" This manpage is Copyright (C) 1992 Drew Eckhardt; |
ac56b6a8 | 2 | .\" and Copyright (C) 1993 Michael Haardt, Ian Jackson. |
e7bb1f63 | 3 | .\" and Copyright (C) 2006, 2014 Michael Kerrisk |
fea681da | 4 | .\" |
93015253 | 5 | .\" %%%LICENSE_START(VERBATIM) |
fea681da MK |
6 | .\" Permission is granted to make and distribute verbatim copies of this |
7 | .\" manual provided the copyright notice and this permission notice are | |
8 | .\" preserved on all copies. | |
9 | .\" | |
10 | .\" Permission is granted to copy and distribute modified versions of this | |
11 | .\" manual under the conditions for verbatim copying, provided that the | |
12 | .\" entire resulting derived work is distributed under the terms of a | |
13 | .\" permission notice identical to this one. | |
c13182ef | 14 | .\" |
fea681da MK |
15 | .\" Since the Linux kernel and libraries are constantly changing, this |
16 | .\" manual page may be incorrect or out-of-date. The author(s) assume no | |
17 | .\" responsibility for errors or omissions, or for damages resulting from | |
18 | .\" the use of the information contained herein. The author(s) may not | |
19 | .\" have taken the same level of care in the production of this manual, | |
20 | .\" which is licensed free of charge, as they might when working | |
21 | .\" professionally. | |
c13182ef | 22 | .\" |
fea681da MK |
23 | .\" Formatted or processed versions of this manual, if unaccompanied by |
24 | .\" the source, must acknowledge the copyright and authors of this work. | |
4b72fb64 | 25 | .\" %%%LICENSE_END |
fea681da MK |
26 | .\" |
27 | .\" Modified 1993-07-24 by Rik Faith | |
28 | .\" Modified 1996-04-26 by Nick Duffek <nsd@bbc.com> | |
29 | .\" Modified 1996-11-06 by Eric S. Raymond <esr@thyrsus.com> | |
30 | .\" Modified 1997-01-31 by Eric S. Raymond <esr@thyrsus.com> | |
c11b1abf | 31 | .\" Modified 2004-06-23 by Michael Kerrisk <mtk.manpages@gmail.com> |
fea681da | 32 | .\" |
e7bb1f63 | 33 | .TH SYMLINK 2 2014-02-21 "Linux" "Linux Programmer's Manual" |
fea681da | 34 | .SH NAME |
e7bb1f63 | 35 | symlink, symlinkat \- make a new name for a file |
fea681da | 36 | .SH SYNOPSIS |
e7bb1f63 | 37 | .nf |
fea681da MK |
38 | .B #include <unistd.h> |
39 | .sp | |
bcd49f31 | 40 | .BI "int symlink(const char *" target ", const char *" linkpath ); |
cc4615cc | 41 | .sp |
e7bb1f63 MK |
42 | .BR "#include <fcntl.h> " "/* Definition of AT_* constants */" |
43 | .B #include <unistd.h> | |
44 | .sp | |
45 | .BI "int symlinkat(const char *" target ", int " newdirfd \ | |
46 | ", const char *" linkpath ); | |
47 | .sp | |
48 | .fi | |
cc4615cc MK |
49 | .in -4n |
50 | Feature Test Macro Requirements for glibc (see | |
51 | .BR feature_test_macros (7)): | |
52 | .in | |
53 | .sp | |
54 | .ad l | |
55 | .BR symlink (): | |
cde2506f MK |
56 | .RS 4 |
57 | _BSD_SOURCE || _XOPEN_SOURCE\ >=\ 500 || | |
58 | _XOPEN_SOURCE\ &&\ _XOPEN_SOURCE_EXTENDED || _POSIX_C_SOURCE\ >=\ 200112L | |
59 | .RE | |
e7bb1f63 MK |
60 | .sp |
61 | .BR symlinkat (): | |
62 | .PD 0 | |
63 | .ad l | |
64 | .RS 4 | |
65 | .TP 4 | |
66 | Since glibc 2.10: | |
67 | _XOPEN_SOURCE\ >=\ 700 || _POSIX_C_SOURCE\ >=\ 200809L | |
68 | .TP | |
69 | Before glibc 2.10: | |
70 | _ATFILE_SOURCE | |
71 | .RE | |
cc4615cc | 72 | .ad b |
e7bb1f63 | 73 | .PD |
fea681da | 74 | .SH DESCRIPTION |
e511ffb6 | 75 | .BR symlink () |
fea681da | 76 | creates a symbolic link named |
f2ae6dde | 77 | .I linkpath |
fea681da | 78 | which contains the string |
bcd49f31 | 79 | .IR target . |
fea681da | 80 | |
cf50118f | 81 | Symbolic links are interpreted at run time as if the contents of the |
fea681da MK |
82 | link had been substituted into the path being followed to find a file or |
83 | directory. | |
84 | ||
85 | Symbolic links may contain | |
836f07c1 | 86 | .I .. |
fea681da MK |
87 | path components, which (if used at the start of the link) refer to the |
88 | parent directories of that in which the link resides. | |
89 | ||
90 | A symbolic link (also known as a soft link) may point to an existing | |
91 | file or to a nonexistent one; the latter case is known as a dangling | |
92 | link. | |
93 | ||
94 | The permissions of a symbolic link are irrelevant; the ownership is | |
95 | ignored when following the link, but is checked when removal or | |
96 | renaming of the link is requested and the link is in a directory with | |
97 | the sticky bit | |
98 | .RB ( S_ISVTX ) | |
99 | set. | |
100 | ||
101 | If | |
f2ae6dde | 102 | .I linkpath |
fea681da MK |
103 | exists it will |
104 | .I not | |
105 | be overwritten. | |
e7bb1f63 MK |
106 | .SS symlinkat() |
107 | The | |
108 | .BR symlinkat () | |
109 | system call operates in exactly the same way as | |
cadd38ba | 110 | .BR symlink (), |
e7bb1f63 MK |
111 | except for the differences described here. |
112 | ||
113 | If the pathname given in | |
114 | .I linkpath | |
115 | is relative, then it is interpreted relative to the directory | |
116 | referred to by the file descriptor | |
117 | .I newdirfd | |
118 | (rather than relative to the current working directory of | |
119 | the calling process, as is done by | |
cadd38ba | 120 | .BR symlink () |
e7bb1f63 MK |
121 | for a relative pathname). |
122 | ||
123 | If | |
124 | .I linkpath | |
125 | is relative and | |
126 | .I newdirfd | |
127 | is the special value | |
128 | .BR AT_FDCWD , | |
129 | then | |
130 | .I linkpath | |
131 | is interpreted relative to the current working | |
132 | directory of the calling process (like | |
cadd38ba | 133 | .BR symlink ()). |
e7bb1f63 MK |
134 | |
135 | If | |
136 | .I linkpath | |
137 | is absolute, then | |
138 | .I newdirfd | |
139 | is ignored. | |
47297adb | 140 | .SH RETURN VALUE |
c13182ef MK |
141 | On success, zero is returned. |
142 | On error, \-1 is returned, and | |
fea681da MK |
143 | .I errno |
144 | is set appropriately. | |
145 | .SH ERRORS | |
146 | .TP | |
147 | .B EACCES | |
148 | Write access to the directory containing | |
f2ae6dde | 149 | .I linkpath |
fea681da | 150 | is denied, or one of the directories in the path prefix of |
f2ae6dde | 151 | .I linkpath |
fea681da MK |
152 | did not allow search permission. |
153 | (See also | |
ad7cc990 | 154 | .BR path_resolution (7).) |
fea681da | 155 | .TP |
a1f01685 | 156 | .B EDQUOT |
9ee4a2b6 | 157 | The user's quota of resources on the filesystem has been exhausted. |
28955f15 SP |
158 | The resources could be inodes or disk blocks, depending on the filesystem |
159 | implementation. | |
a1f01685 | 160 | .TP |
fea681da | 161 | .B EEXIST |
f2ae6dde | 162 | .I linkpath |
fea681da MK |
163 | already exists. |
164 | .TP | |
165 | .B EFAULT | |
bcd49f31 | 166 | .IR target " or " linkpath " points outside your accessible address space." |
fea681da MK |
167 | .TP |
168 | .B EIO | |
169 | An I/O error occurred. | |
170 | .TP | |
171 | .B ELOOP | |
172 | Too many symbolic links were encountered in resolving | |
f2ae6dde | 173 | .IR linkpath . |
fea681da MK |
174 | .TP |
175 | .B ENAMETOOLONG | |
bcd49f31 | 176 | .IR target " or " linkpath " was too long." |
fea681da MK |
177 | .TP |
178 | .B ENOENT | |
179 | A directory component in | |
f2ae6dde | 180 | .I linkpath |
fea681da | 181 | does not exist or is a dangling symbolic link, or |
bcd49f31 | 182 | .I target |
fea681da MK |
183 | is the empty string. |
184 | .TP | |
185 | .B ENOMEM | |
186 | Insufficient kernel memory was available. | |
187 | .TP | |
188 | .B ENOSPC | |
189 | The device containing the file has no room for the new directory | |
190 | entry. | |
191 | .TP | |
192 | .B ENOTDIR | |
193 | A component used as a directory in | |
f2ae6dde | 194 | .I linkpath |
fea681da MK |
195 | is not, in fact, a directory. |
196 | .TP | |
197 | .B EPERM | |
9ee4a2b6 | 198 | The filesystem containing |
f2ae6dde | 199 | .I linkpath |
fea681da MK |
200 | does not support the creation of symbolic links. |
201 | .TP | |
202 | .B EROFS | |
f2ae6dde | 203 | .I linkpath |
9ee4a2b6 | 204 | is on a read-only filesystem. |
e7bb1f63 MK |
205 | .PP |
206 | The following additional errors can occur for | |
207 | .BR symlinkat (): | |
208 | .TP | |
209 | .B EBADF | |
210 | .I newdirfd | |
211 | is not a valid file descriptor. | |
212 | .TP | |
213 | .B ENOTDIR | |
214 | .I linkpath | |
215 | is relative and | |
216 | .I newdirfd | |
217 | is a file descriptor referring to a file other than a directory. | |
218 | .SH VERSIONS | |
219 | .BR symlinkat () | |
220 | was added to Linux in kernel 2.6.16; | |
221 | library support was added to glibc in version 2.4. | |
47297adb | 222 | .SH CONFORMING TO |
e7bb1f63 | 223 | .BR symlink (): |
dc3884b8 | 224 | SVr4, 4.3BSD, POSIX.1-2001, POSIX.1-2008. |
2dd578fd MK |
225 | .\" SVr4 documents additional error codes EDQUOT and ENOSYS. |
226 | .\" See | |
227 | .\" .BR open (2) | |
228 | .\" re multiple files with the same name, and NFS. | |
e7bb1f63 MK |
229 | |
230 | .BR symlinkat (): | |
231 | POSIX.1-2008. | |
fea681da MK |
232 | .SH NOTES |
233 | No checking of | |
bcd49f31 | 234 | .I target |
fea681da MK |
235 | is done. |
236 | ||
d44ab9f9 | 237 | Deleting the name referred to by a symbolic link will actually delete the |
7c93fec0 | 238 | file (unless it also has other hard links). |
d9bfdb9c | 239 | If this behavior is not desired, use |
0bfa087b | 240 | .BR link (2). |
47297adb | 241 | .SH SEE ALSO |
fea681da | 242 | .BR ln (1), |
a3bf8022 | 243 | .BR lchown (2), |
fea681da MK |
244 | .BR link (2), |
245 | .BR lstat (2), | |
246 | .BR open (2), | |
fea681da MK |
247 | .BR readlink (2), |
248 | .BR rename (2), | |
0c2b92ba | 249 | .BR unlink (2), |
a9cfde1d | 250 | .BR path_resolution (7), |
ad22ad55 | 251 | .BR symlink (7) |