Visual QuickStart Guide [Electronic resources] : Mac OS X 10.4 Tiger نسخه متنی

Making Symbolic Links with ln

Mac OS enables you to make aliases to files. It should come as no surprise that Unix does, too. But in Unix, aliases are called

symbolic links . And rather than use a menu command or shortcut key to create them, you use the ln (make links) command with its -s option.

Tips

• Mac OS aliases and Unix symbolic links make it convenient to access deeply buried files or to organize files differently than the way the operating system organizes them.

• If you omit the -s option, the ln command creates a hard link. Hard links can't cross file systems (or partitions) and can't normally refer to directories.

• Unix does not tell you if the source file to which you want to create a symbolic link does not exist. As a result, it's possible to create an alias that doesn't point to anything.

• You can learn more about other options for the ln command in its man pages. Type man ln and press to display them.

To make a link to a file

Type ln -s

source-file target-file and press (Figure 23 ).

For example, ln -s file1 alias1 creates an alias called

alias1 that points to the file called

file1 . In this example, both files (the source and the target) are in the current directory.

To make a link to a directory

Type ln -s

source-directory target-file and press (