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When we type ls -l, we get meta data regarding all the objects in the current directory.
The meta data has 10 dashes and the 1st dash indicates if the object is a directory or file or a link
d indicates that the object is a directory like a folder
- indicates that the object is a file etc : .cpp, .png, .jpeg
l indicates that the object is a link
What exactly does it mean when a object is a link, how do you create a object that is a link?
The l you're referencing means the file is a link (symbolic) to another file (or directory).
lrwxrwxrwx. 1 root root 22 Feb 24 17:36 jcmd -> /etc/alternatives/jcmd
lrwxrwxrwx. 1 root root 23 Feb 24 17:36 javap -> /etc/alternatives/javap
lrwxrwxrwx. 1 root root 23 Feb 24 17:36 javah -> /etc/alternatives/javah
These were created with a command, ln -s source link. The source is the file/directory we want to link to, the "link" is the name we want to give the link.
making a link
$ ln -s ~/winfile.txt a_link.txt
confirming
$ ls -l | grep winfile
lrwxrwxrwx. 1 saml saml 22 Mar 5 11:15 a_link.txt -> /home/saml/winfile.txt
-rw-rw-r--. 1 saml saml 41 Mar 5 07:44 winfile.txt
If you consult the info ls info page you'll find descriptions of all the symbols used in the output of ls.
excerpt
The file type is one of the following characters:
'-' regular file
'b' block special file
'c' character special file
'C' high performance ("contiguous data") file
'd' directory
'D' door (Solaris 2.5 and up)
'l' symbolic link
'M' off-line ("migrated") file (Cray DMF)
'n' network special file (HP-UX)
'p' FIFO (named pipe)
'P' port (Solaris 10 and up)
's' socket
'?' some other file type
10.1.2 What information is listed - coreutils documentation on ls
a symbolic link is a reference to another file.
you create it with the ln command:
ln -s /some/file mylink
l indicates that the object is a symbolic link. This is simply a pointer to some other object, which may or may not exist. Attempts to access the link will result in the object being pointed to being accessed instead. The object could be anything: a file, directory or special file will all work.
For example, in your root directory you may well have this:
lrwxrwxrwx 1 root root 27 Sep 12 2012 /vmlinuz -> boot/vmlinuz-2.6.32-5-amd64
This means that, when /vmlinuz is accessed, the file being pointed to is read instead. If that file doesn't exist, the operation will fail.
To create a symbolic link, use the command
ln -s source-file link-file
This will create a link that looks like
link-file -> source-file
Note that this is distinct from a hard link, created by omitting the -s option. A hard link creates a filesystem pointer to the same inode as that used by the source object, and can't point to an object on a different filesystem.
