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28 .\" @(#)link.2 8.3 (Berkeley) 1/12/94
37 .Nd make a hard file link
43 .Fn link "const char *name1" "const char *name2"
46 .Fa "int fd1" "const char *name1" "int fd2" "const char *name2" "int flag"
52 atomically creates the specified directory entry (hard link)
54 with the attributes of the underlying object pointed at by
56 If the link is successful: the link count of the underlying object
61 share equal access and rights
69 is not deleted and the link count of the
73 The object pointed at by the
76 must exist for the hard link to
82 must be in the same file system.
86 may not be a directory.
90 system call is equivalent to
92 except in the case where either
96 or both are relative paths.
97 In this case a relative path
99 is interpreted relative to
100 the directory associated with the file descriptor
102 instead of the current working directory and similarly for
104 and the file descriptor
109 are constructed by a bitwise-inclusive OR of flags from the following
112 .Bl -tag -width indent
113 .It Dv AT_SYMLINK_FOLLOW
116 names a symbolic link, a new link for the target of the symbolic link is
119 Only allow to link to a file which is beneath of the topping directory.
120 See the description of the
129 is passed the special value
135 parameter, the current working directory is used for the respective
144 the behavior is identical to a call to
149 .Dv AT_SYMLINK_FOLLOW
152 names a symbolic link, a new link is created for the symbolic link
161 will fail and no link will be created if:
164 A component of either path prefix is not a directory.
165 .It Bq Er ENAMETOOLONG
166 A component of either pathname exceeded 255 characters,
167 or entire length of either path name exceeded 1023 characters.
169 A component of either path prefix does not exist.
171 The file system containing the file named by
173 does not support links.
175 The link count of the file named by
179 A component of either path prefix denies search permission.
181 The requested link requires writing in a directory with a mode
182 that denies write permission.
184 Too many symbolic links were encountered in translating one of the pathnames.
200 has its immutable or append-only flag set, see the
202 manual page for more information.
204 The parent directory of the file named by
206 has its immutable flag set.
210 and the file named by
212 are on different file systems.
214 The directory in which the entry for the new link is being placed
215 cannot be extended because there is no space left on the file
216 system containing the directory.
218 The directory in which the entry for the new link
219 is being placed cannot be extended because the
220 user's quota of disk blocks on the file system
221 containing the directory has been exhausted.
223 An I/O error occurred while reading from or writing to
224 the file system to make the directory entry.
226 The requested link requires writing in a directory on a read-only file
229 One of the pathnames specified
230 is outside the process's allocated address space.
233 In addition to the errors returned by the
237 system call may fail if:
244 argument does not specify an absolute path and the
248 argument, respectively, is neither
250 nor a valid file descriptor open for searching.
254 argument is not valid.
260 argument is not an absolute path and
264 respectively, is neither
266 nor a file descriptor associated with a directory.
267 .It Bq Er ENOTCAPABLE
269 is not strictly relative to the starting directory.
272 is absolute or includes a ".." component that escapes
273 the directory hierarchy specified by
275 and the process is in capability mode.
276 .It Bq Er ENOTCAPABLE
281 and the absolute path
283 does not have its tail fully contained under the topping directory,
296 system call is expected to conform to
300 system call follows The Open Group Extended API Set 2 specification.
308 system call appeared in
313 system call traditionally allows the super-user to link directories which
314 corrupts the file system coherency.
315 This implementation no longer permits it.