bash magic

Some handy bash magic.

sudo last command

sudo !!

If you forgot sudo after executing your 3-lines-command, sudo bang! bang! will repeat the last entered command with sudo prefixed.

bang	Expands to
`!$`	last argument of previous command
`!$:p`	just show last argument of previous command, don't add to commandline
`!*`	all arguments of previous command
`!!:1`	first argument of previous command
`!vi`	last command that started with "vi"
`!vi:p`	just show last "vi"-call, don't run it again
`^err^corr`	replace all occurrences of `err` by `corr` in the last command

keypress	Description
`Ctrl`+`w`	Erase word
`Ctrl`+`u`	Erase from cursor to beginning of line
`Ctrl`+`a`	Move cursor to beginning of line
`Ctrl`+`e`	Move cursor to end of line
`Ctrl`+`r`	Search command history (type letters after this)

cd -

Changes to previous directory.

Sometimes it's handy to use the output of a previous command, e.g. a which. To do that, simply use the bang-bang with the backtick operator:

$ which php
/usr/bin/php
$ ls -l `!!`
ls -l `which php`
lrwxrwxrwx 1 root root 21 2008-06-12 02:47 /usr/bin/php -> /etc/alternatives/php
$ _