symlink.2

早期freebsd实现

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.\"     @(#)symlink.2	8.1 (Berkeley) 6/4/93
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.Dd June 4, 1993
.Dt SYMLINK 2
.Os BSD 4.2
.Sh NAME
.Nm symlink
.Nd make symbolic link to a file
.Sh SYNOPSIS
.Fd #include <unistd.h>
.Ft int
.Fn symlink "const char *name1" "const char *name2"
.Sh DESCRIPTION
A symbolic link
.Fa name2
is created to
.Fa name1
.Pf ( Fa name2
is the name of the
file created,
.Fa name1
is the string
used in creating the symbolic link).
Either name may be an arbitrary path name; the files need not
be on the same file system.
.Sh RETURN VALUES
Upon successful completion, a zero value is returned.
If an error occurs, the error code is stored in
.Va errno
and a -1 value is returned.
.Sh ERRORS
The symbolic link succeeds unless:
.Bl -tag -width ENAMETOO
.It Bq Er ENOTDIR
A component of the
.Fa name2
prefix is not a directory.
.It Bq Er EINVAL
Either
.Fa name1
or
.Fa name2
contains a character with the high-order bit set.
.It Bq Er ENAMETOOLONG
A component of either pathname exceeded 255 characters,
or the entire length of either path name exceeded 1023 characters.
.It Bq Er ENOENT
The named file does not exist.
.It Bq Er EACCES
A component of the
.Fa name2
path prefix denies search permission.
.It Bq Er ELOOP
Too many symbolic links were encountered in translating the pathname.
.It Bq Er EEXIST
.Fa Name2
already exists.
.It Bq Er EIO
An I/O error occurred while making the directory entry for
.Fa name2 ,
or allocating the inode for
.Fa name2 ,
or writing out the link contents of
.Fa name2 .
.It Bq Er EROFS
The file
.Fa name2
would reside on a read-only file system.
.It Bq Er ENOSPC
The directory in which the entry for the new symbolic link is being placed
cannot be extended because there is no space left on the file
system containing the directory.
.It Bq Er ENOSPC
The new symbolic link cannot be created because there
there is no space left on the file
system that will contain the symbolic link.
.It Bq Er ENOSPC
There are no free inodes on the file system on which the
symbolic link is being created.
.It Bq Er EDQUOT
The directory in which the entry for the new symbolic link
is being placed cannot be extended because the
user's quota of disk blocks on the file system
containing the directory has been exhausted.
.It Bq Er EDQUOT
The new symbolic link cannot be created because the user's
quota of disk blocks on the file system that will
contain the symbolic link has been exhausted.
.It Bq Er EDQUOT
The user's quota of inodes on the file system on
which the symbolic link is being created has been exhausted.
.It Bq Er EIO
An I/O error occurred while making the directory entry or allocating the inode.
.It Bq Er EFAULT
.Fa Name1
or
.Fa name2
points outside the process's allocated address space.
.El
.Sh SEE ALSO
.Xr link 2 ,
.Xr ln 1 ,
.Xr unlink 2
.Sh HISTORY
The
.Nm
function call appeared in
.Bx 4.2 .