TIP: Bash has “global search and replace”!

TIP: Bash has “global search and replace”! It works with the history mechanism. Example, the bangbang (!!) command repeats the previous command:

$ !! # repeat previous command

Adding a colon (:) and then a letter or two will modify the command before running it.  A useful modifier is “p” for printing.  That is:

$ !!:p # repeat previous command, but just :p-print it

This is useful because you can use up-arrow to now go to the previous command and edit it interactively.

For non-interactive editing, you can do global search and replace!  Example: use the “repeat previous command” command, bangbang (!!). Then modify it (:), then say “global search” (gs).  To do this to find “one” and replace it with “two”, use this command:

$ !!:gs/one/two

In my real-world case, I’d already run a command to deploy my Development server with Terraform. The specific command is:

AWS_PROFILE=development terraform plan -var-file=../config/development.tfvars

This command was in my shell history.  I want to recall this command (bangbang, aka !!), then search and replace “development” with “staging” to use Terraform to deploy to my staging environment.

Command:

$ !!:gs/development/staging

Got me:

AWS_PROFILE=staging terraform plan -var-file=../config/staging.tfvars

Resources:


– Bash scripting cheatsheet