xref: /netbsd-src/lib/libc/sys/link.2 (revision 76dfffe33547c37f8bdd446e3e4ab0f3c16cea4b)
1.\"	$NetBSD: link.2,v 1.7 1995/02/27 12:34:01 cgd Exp $
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34.\"     @(#)link.2	8.3 (Berkeley) 1/12/94
35.\"
36.Dd January 12, 1994
37.Dt LINK 2
38.Os BSD 4
39.Sh NAME
40.Nm link
41.Nd make a hard file link
42.Sh SYNOPSIS
43.Fd #include <unistd.h>
44.Ft int
45.Fn link "const char *name1" "const char *name2"
46.Sh DESCRIPTION
47The
48.Fn link
49function call
50atomically creates the specified directory entry (hard link)
51.Fa name2
52with the attributes of the underlying object pointed at by
53.Fa name1
54If the link is successful: the link count of the underlying object
55is incremented;
56.Fa name1
57and
58.Fa name2
59share equal access and rights
60to the
61underlying object.
62.Pp
63If
64.Fa name1
65is removed, the file
66.Fa name2
67is not deleted and the link count of the
68underlying object is
69decremented.
70.Pp
71.Fa Name1
72must exist for the hard link to
73succeed and
74both
75.Fa name1
76and
77.Fa name2
78must be in the same file system.
79Unless the caller is the super-user,
80.Fa name1
81may not be a directory.
82.Sh RETURN VALUES
83Upon successful completion, a value of 0 is returned.  Otherwise,
84a value of -1 is returned and
85.Va errno
86is set to indicate the error.
87.Sh ERRORS
88.Fn Link
89will fail and no link will be created if:
90.Bl -tag -width Er
91.It Bq Er ENOTDIR
92A component of either path prefix is not a directory.
93.It Bq Er ENAMETOOLONG
94A component of a pathname exceeded
95.Dv {NAME_MAX}
96characters, or an entire path name exceeded
97.Dv {PATH_MAX}
98characters.
99.It Bq Er ENOENT
100A component of either path prefix does not exist.
101.It Bq Er EACCES
102A component of either path prefix denies search permission.
103.It Bq Er EACCES
104The requested link requires writing in a directory with a mode
105that denies write permission.
106.It Bq Er ELOOP
107Too many symbolic links were encountered in translating one of the pathnames.
108.It Bq Er ENOENT
109The file named by
110.Fa name1
111does not exist.
112.It Bq Er EEXIST
113The link named by
114.Fa name2
115does exist.
116.It Bq Er EPERM
117The file named by
118.Fa name1
119is a directory and the effective
120user ID is not super-user.
121.It Bq Er EXDEV
122The link named by
123.Fa name2
124and the file named by
125.Fa name1
126are on different file systems.
127.It Bq Er ENOSPC
128The directory in which the entry for the new link is being placed
129cannot be extended because there is no space left on the file
130system containing the directory.
131.ne 3v
132.It Bq Er EDQUOT
133The directory in which the entry for the new link
134is being placed cannot be extended because the
135user's quota of disk blocks on the file system
136containing the directory has been exhausted.
137.It Bq Er EIO
138An I/O error occurred while reading from or writing to
139the file system to make the directory entry.
140.It Bq Er EROFS
141The requested link requires writing in a directory on a read-only file
142system.
143.It Bq Er EFAULT
144One of the pathnames specified
145is outside the process's allocated address space.
146.El
147.Sh SEE ALSO
148.Xr symlink 2 ,
149.Xr unlink 2
150.Sh STANDARDS
151The
152.Fn link
153function is expected to conform to
154.St -p1003.1-88 .
155