Shell Session Command History

Ubuntu Tutorials - Herong's Tutorial Examples

∟Shell Session Command History

This section provides a tutorial example on how to use Bash shell command history functionalities.

Another nice feature of Bash is the session command history, which records every command you entered in an interactive session. Using this command history, Bash provides the following functionalities:

"history" command - To view past commands.
Up/Down arrow keys - To scroll back and forth past commands.
!{number} - To re-run the past command at the history line number.
!{pattern} - To re-run the past command that matches the given pattern.
~/.bash_history - To carry past commands from the previous session to the next session. When Bash session starts, it restores history from ~/.bash_history. When Bash session ends, it dumps history to ~/.bash_history.

Here is an example of how to view and re-run past commands.

herong$ history 
 ...
 2002  top
 2003  ps -e 
 2004  ps -e -o pid,euser,%cpu,%mem,rss,drs,trs,sz,vsz,comm
 2005  ps -e --sort rss -o pid,euser,%cpu,%mem,rss,drs,trs,sz,vsz,comm 
 2006  ps -e --sort -rss -o pid,euser,%cpu,%mem,rss,drs,trs,sz,vsz,comm 
 2007  history
 
herong$ !2006 
  PID EUSER  %CPU %MEM    RSS     DRS    TRS      SZ     VSZ COMMAND
 2330 herong  0.7  5.7 212348 4287442     13 1071864 4287456 gnome-shell
 9323 herong  0.2  5.1 189428 4951095 119740 1267709 5070836 atom
 9384 herong  0.2  5.1 189284 4976335 119740 1274019 5096076 atom
26649 herong  0.0  4.8 180500  931929   3790  233930  935720 update-manager
 2666 herong  0.0  4.4 166892 1344245    946  336298 1345192 gnome-software
23305 herong  0.0  3.7 138136  530617   3790  133602  534408 apport-gtk
20386 herong  0.0  2.3  87556 1514653   4398  379763 1519052 gnome-control-c
 9458 herong  0.0  2.1  78364 4620995 119740 1185184 4740736 atom
 2202 herong  0.7  1.6  60468 1046175   2308  262121 1048484 Xorg
 ...