Usefull bits and pieces

Abbreviate commands - alias

In the case you use certain (complex) commands frequently, you may enter this
command using another command name to the file .alias in your home directory
(more detailed information: man alias).

tab-completion

Most text consoles (e.g. xterm) provide tab-completion. If you enter the initial
character(s) of a command and hit [tab] (key with the double arrow symbol), then
the command will be completed if unambiguous. You may hit the [tab] key twice
to show all possible commands beginning with the already entered characters.

less, more, grep

If you append the character | (accompanied by a blank space in left and right
position) to your command, you may edit the resulting output of the command.
The commands less and more will return the output piecewise that means page
by page (e.g. ll | less). You may use the arrow keys or [Enter] to scroll,
key [q]) terminates this modus To search the output for a pattern of characters,
you may use grep. E.g. ll | grep foo filters the output of ll for all rows
containing the pattern foo.)