Command history, editing, and substitution
Shell sessions can be viewed as a conversation. History, expansion, and editing make that dialog more productive.
Commands can be reissued, modified, and edited. Examples are shown in Table 10-3.
Command substitution allows the result of a command to be placed into a shell variable.
Ctrl-P, previous line
Ctrl-K, kill to end of line
Ctrl-Y, paste (yank) text