Bash History Substitution

Transcript

1. Bash History Substitution Daniel Brook-Roberge September 3, 2015 Engineering Meeting
2. !! : The Last Command • The last command can be repeated with !! • This can be used on its own or included into a larger command.
3. Relative Indexing with !- • We can look further back in the history using !-n, where n is the number of commands to go back. • This allows us to repeat the last two commands on one line with !-2 && !!
4. History Searching • We can search through the history with characters after the !. • !t is substituted with the most recent command that begins with t, for example.
5. Modifications with :s/ and :gs/ • We can perform string substitution on a history command with :s/old/new/ • This will only replace the first occurrence, to replace all, use :gs/old/new/ • We can use ^old^new as a shorthand for !!:s/old/new/
6. Accessing Arguments: !$ and !* • With !$, we can pick out the final argument of the previous command. • To get all of the arguments, we can use !* instead.
7. Summary Command Replaced by !! Previous command !-2 Command before last !r Last command beginning with r !!:s/in/out/ Last command with the first in replaced by out !!:gs/in/out/ Last command with all in replaced by out !$ The final argument to the last command !* All arguments to the last command