Aliases

alias rm   "rm -i"
alias dir  "ls -al | more"

The syntax for the alias command is:

alias name value

The first argument to the alias command is the name of the alias you are creating, such as dir. The second argument to the alias command is the actual command(s) that will be executed when you type in the name of the new alias.

Using the examples above, when you type dir, the actual command that is executed by your C shell is "ls -al | more". In your home directory it would look something like this:

sys_name% dir

total 12
drwxr-xr-x   2 stu1     class       1024 Mar 25 10:56 .
drwxrwxr-x   7 root     sys           96 Mar 25 10:22 ..
-rw-r--r--   1 stu1     class          0 Mar 22 14:28 .news\_time
-rw-r--r--   1 stu1     class       1956 Mar 25 10:52 .profile
-rw-------   1 stu1     class        222 Mar 25 10:56 .sh\_history
-rw-r--r--   1 stu1     class         64 Feb  3 13:39 .vtlrc
-rw-r--r--   1 stu1     class        531 Feb  3 13:39 .vtlrc.els

sys_name% _

As mentioned, you can assign new names to existing Unix commands with the alias command. Why would you want to rename an existing Unix command? How about the following example?

alias  rm  "rm -i"

In this example, you have "safeguarded" the remove (rm) command. In this way, each time you attempt to remove a file by typing "rm filename", you will be prompted with "are you sure" before the file is removed. This gives an extra layer of protection from accidently deleting valuable files.

Why else would you want to rename a Unix command? How about "grep"?

If you type the command alias by itself, the C shell will list all of the currently defined aliases:

sys_name%  alias

dir   "ls -al | more"
disk    "df -k"
h     history
k9    "kill -9"
md    mkdir
rd    rmdir
vt100   "set term=vt100"
what    "ps -ef"
wy60    "set term=wyse60"

sys_name%  _

• Other alias notes: