Definition: alias is a built-in shell command in Linux / Unix operating systems. It can save you a lot of typing by assigning a name to long commands. For example, if you need to repeatedly copy files from one directory to another using the command
cp /home/jones/data1/* /usr/local/share/latest/.
you can replace this long command line with a short easy to remember name like "moveit" using the alias command as follows:
alias moveit="cp /home/jones/data1/* /usr/local/share/latest/."
Then you can just
type "moveit" at the command prompt and it will do the same copy operation.
If you change your mind and want to assign a different command to the alias, you do it same way-the previous definition will be overwritten.
If you don't want
anything assigned to the alias anymore you can un-set it using "unalias":
If you want to check all the alias definitions currently active, simply type alias without any arguments:
An alias definition
is valid only in the current shell execution environment and the execution environments
of its subshells.
Linux / Unix commands are introducted one by one.