diff options
| -rw-r--r-- | bin/ln/ln.1 | 66 |
1 files changed, 49 insertions, 17 deletions
diff --git a/bin/ln/ln.1 b/bin/ln/ln.1 index 6cfa21a2332..e519288e61b 100644 --- a/bin/ln/ln.1 +++ b/bin/ln/ln.1 @@ -1,4 +1,4 @@ -.\" $OpenBSD: ln.1,v 1.7 1999/08/16 18:40:03 aaron Exp $ +.\" $OpenBSD: ln.1,v 1.8 1999/09/23 19:15:49 aaron Exp $ .\" $NetBSD: ln.1,v 1.10 1995/07/25 19:37:04 jtc Exp $ .\" .\" Copyright (c) 1980, 1990, 1993 @@ -42,7 +42,7 @@ .Os .Sh NAME .Nm ln -.Nd make links +.Nd make hard and symbolic links to files .Sh SYNOPSIS .Nm ln .Op Fl fs @@ -58,14 +58,12 @@ The utility creates a new directory entry (linked file) which has the same modes as the original file. It is useful for maintaining multiple copies of a file in many places -at once without using up storage for the -.Dq copies ; +at once without using up storage for the copies; instead, a link .Dq points to the original copy. There are two types of links; hard links and symbolic links. -How a link -.Dq points +How a link points to a file is one of the differences between a hard and symbolic link. .Pp The options are as follows: @@ -79,7 +77,7 @@ Create a symbolic link. By default, .Nm makes -.Em hard +.Dq hard links. A hard link to a file is indistinguishable from the original directory entry; any changes to a file are effectively independent of the name used to reference @@ -87,32 +85,34 @@ the file. Hard links may not normally refer to directories and may not span file systems. .Pp A symbolic link contains the name of the file to -which it is linked. The referenced file is used when an -.Xr open 2 +which it is linked. +The referenced file is used when an +.Xr open 2 operation is performed on the link. A -.Xr stat 2 +.Xr stat 2 on a symbolic link will return the linked-to file; an -.Xr lstat 2 +.Xr lstat 2 must be done to obtain information about the link. The -.Xr readlink 2 +.Xr readlink 2 call may be used to read the contents of a symbolic link. -Symbolic links may span file systems and may refer to directories. +Symbolic links may span file systems, refer to directories, and refer to +non-existent files. .Pp Given one or two arguments, .Nm creates a link to an existing file -.Ar source_file . +.Ar source_file . If .Ar target_file is given, the link has that name; .Ar target_file -may also be a directory in which to place the link; -otherwise it is placed in the current directory. +may also be a directory in which to place the link. +Otherwise, it is placed in the current directory. If only the directory is specified, the link will be made to the last component of -.Ar source_file . +.Ar source_file . .Pp Given more than two arguments, .Nm @@ -120,6 +120,38 @@ makes links in .Ar target_dir to all the named source files. The links made will have the same name as the files being linked to. +.Sh EXAMPLES +Create a symbolic link named +.Pa /home/www +and point it to +.Pa /var/www : +.Pp +.D1 Ic ln -s /var/www /home/www +.Pp +Hard link +.Pa /usr/local/bin/fooprog +to file +.Pa /usr/local/bin/fooprog-1.0 : +.Pp +.D1 Ic ln /usr/local/bin/fooprog-1.0 /usr/local/bin/fooprog +.Pp +As an exercise, try the following commands: +.Pp +.D1 Ic $ ls -i /bin/[ +.D1 Li 11553 /bin/[ +.D1 Ic $ ls -i /bin/test +.D1 Li 11553 /bin/test +.Pp +Note that both files have the same inode; that is, +.Pa /bin/[ +is essentially an alias for the +.Xr test 1 +command. +This hard link exists so +.Xr test 1 +may be invoked from shell scripts, for example, using the +.Cm "if [ ]" +construct. .Sh SEE ALSO .Xr link 2 , .Xr lstat 2 , |