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.

Table 10-3. Shell expansion, editing, and substitution examples

History type

Examples

Expansion

!!
 
!n
 
^string1^string2

Editing

Ctrl-P, previous line

 

Ctrl-K, kill to end of line

 

Ctrl-Y, paste (yank) text

Substitution

VAR=$(command) or VAR='command'

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