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'!!:n' selects the nth argument of the last command, and '!$' the last arg A lot of people know about "!$" (which is shorthand for !!:$), but that's just the t

'!!:n' selects the nth argument of the last command, and '!$' the last arg A lot of people know about "!$" (which is shorthand for !!:$), but that's just the tip of Bash's history expansion. I use these things all the time. One of my favorite keystroke savers is adding :h, the head modifier, to !$. For example: $ cp file.txt /some/annoyingly/deep/target/directory/other.txt $ cd !$:h $ pwd # => /some/annoyingly/deep/target/directory Once you understand how each component works it's easier to put them together into new (to you) combinations. For example, once you know that !$ is shorthand for !!:$, it's not a huge leap to reason out that you can use !-2:$ to get the last argument to the 2nd-to-last command. Or !ls:$ for the last arg to the most recent `ls` command. I also prefer to do substitution with the :s modifier rather than ^ as suggested at the link, for consistency's sake: $ echo "foo bar" foo bar $ echo !!:s/bar/baz foo baz $ echo !?bar?:s/foo/qux qux bar Relevant Bash manual pages: http://www.gnu.org/software/bash/manual/html_node/Event-Designators.html http://www.gnu.org/software/bash/manual/html_node/Event-Desi... http://www.gnu.org/software/bash/manual/html_node/Word-Designators.html http://www.gnu.org/software/bash/manual/html_node/Word-Desig... http://www.gnu.org/software/bash/manual/html_node/Modifiers.html http://www.gnu.org/software/bash/manual/html_node/Modifiers....

jschmitz28 14y ago
That first example is great, thanks. I run into that all the time. Up until now I've been doing this: $ cp file.txt /some/annoyingly/deep/target/directory/other.txt $ cd !$ (No such file or directory) (up arrow and then backspace to directory)
cschol 14y ago
Alt + . – use the last word of the previous command. $ cp file.txt /some/annoyingly/deep/target/directory/other.txt $ cd then press Alt + . $ pwd # => /some/annoyingly/deep/target/directory
- ralph 14y ago
  No, that gives the last word, as you say, we want the dirname of the last word. $ echo foo/bar foo/bar $ echo !$ !$:h foo/bar foo
  - cschol 14y ago
    Good point. I usually don't supply the file name of the second argument. Then it would be equivalent.
  - kragen 14y ago
    So you say cd M-. M-backspace M-backspace instead of cd M-.. Four keystrokes is still an improvement over shift-1 shift-4 shift-; h, which is five, plus you get to see where you're going to go before you get there.
    - ralph 14y ago
      You're incorrect. The number of M-backspace you appear to need would seem to depend on how many `little' words comprise the part that needs deleting, e.g. foo/2013-03-13 needed three M-backspace to rid me of the date and a further backspace to remove the trailing slash, which isn't insignificant to all commands, e.g. ls -ld bar/ when bar is a symlink. In comparison. !$:h understands its task at a higher level. And thanks to key rollover, typing different characters, like !$:h, is quicker than tapping away at . until visual feedback, which may lag, tells me I've done enough.
      - kragen 14y ago
        It's true that M-backspace is occasionally less convenient, but it's usually more convenient.
pjungwir 14y ago
Another nice ending is `:p` to print the command instead of executing it. I use this if I'm doing something complicated and I want to make sure it's right. Or if I'm saying `!-n:foo` with n>2. Then just up-arrow and enter to run it for real.
- kejadlen 14y ago
  I use magic-space for that in my inputrc: $if Bash Space: magic-space $endif Basically does the same thing as :p, but after a space instead of enter. Edit: fixed formatting.
- cawel 14y ago
  Here is a detail when using '!!:n' with ':p' when trying to iteratively construct a complex command. I want to emphasize the use of the up-arrow (which will show the interpolated arguments), as opposed to rewriting exactly what you wrote in the previous command, since the usage of ':p' will be interpreted by the shell as a command in itself: $ echo a b c d a b c d $ echo !!:2:p echo b $ echo !!:2 -bash: :2: bad word specifier # there was only 1 argument in last command However: $ echo a b c d a b c d $ echo !!:2:p echo b $ <up-arrow pressed once will give the following prompt> $ echo b
- absqua 14y ago
  shopt -s histverify to show the expanded command before executing it. Then just enter. I never get these right the first time.
  - pyre 14y ago
    In zsh, you can hit <tab> to expand it in place before hitting <enter>.
sciurus 14y ago
A sometimes handy addition to the s modifier is g, which replaces all instances of the pattern instead of just the first. $ echo "foo foo" foo foo $ echo !!:s/foo/bar echo echo "bar foo" echo bar foo $ echo "foo foo" foo foo $ echo !!:gs/foo/bar echo echo "bar bar" echo bar bar
hiroaki 14y ago
$ !! runs the previous command. This is especially useful: $ !! $ sudo !!

jschmitz28 14y ago

That first example is great, thanks. I run into that all the time. Up until now I've been doing this: $ cp file.txt /some/annoyingly/deep/target/directory/other.txt $ cd !$ (No such file or directory) (up arrow and then backspace to directory)

cschol 14y ago

Alt + . – use the last word of the previous command. $ cp file.txt /some/annoyingly/deep/target/directory/other.txt $ cd then press Alt + . $ pwd # => /some/annoyingly/deep/target/directory

ralph 14y ago
No, that gives the last word, as you say, we want the dirname of the last word. $ echo foo/bar foo/bar $ echo !$ !$:h foo/bar foo
- cschol 14y ago
  Good point. I usually don't supply the file name of the second argument. Then it would be equivalent.
- kragen 14y ago
  So you say cd M-. M-backspace M-backspace instead of cd M-.. Four keystrokes is still an improvement over shift-1 shift-4 shift-; h, which is five, plus you get to see where you're going to go before you get there.
  - ralph 14y ago
    You're incorrect. The number of M-backspace you appear to need would seem to depend on how many `little' words comprise the part that needs deleting, e.g. foo/2013-03-13 needed three M-backspace to rid me of the date and a further backspace to remove the trailing slash, which isn't insignificant to all commands, e.g. ls -ld bar/ when bar is a symlink. In comparison. !$:h understands its task at a higher level. And thanks to key rollover, typing different characters, like !$:h, is quicker than tapping away at . until visual feedback, which may lag, tells me I've done enough.
    - kragen 14y ago
      It's true that M-backspace is occasionally less convenient, but it's usually more convenient.

pjungwir 14y ago

Another nice ending is `:p` to print the command instead of executing it. I use this if I'm doing something complicated and I want to make sure it's right. Or if I'm saying `!-n:foo` with n>2. Then just up-arrow and enter to run it for real.

kejadlen 14y ago
I use magic-space for that in my inputrc: $if Bash Space: magic-space $endif Basically does the same thing as :p, but after a space instead of enter. Edit: fixed formatting.
cawel 14y ago
Here is a detail when using '!!:n' with ':p' when trying to iteratively construct a complex command. I want to emphasize the use of the up-arrow (which will show the interpolated arguments), as opposed to rewriting exactly what you wrote in the previous command, since the usage of ':p' will be interpreted by the shell as a command in itself: $ echo a b c d a b c d $ echo !!:2:p echo b $ echo !!:2 -bash: :2: bad word specifier # there was only 1 argument in last command However: $ echo a b c d a b c d $ echo !!:2:p echo b $ <up-arrow pressed once will give the following prompt> $ echo b
absqua 14y ago
shopt -s histverify to show the expanded command before executing it. Then just enter. I never get these right the first time.
- pyre 14y ago
  In zsh, you can hit <tab> to expand it in place before hitting <enter>.

sciurus 14y ago

A sometimes handy addition to the s modifier is g, which replaces all instances of the pattern instead of just the first. $ echo "foo foo" foo foo $ echo !!:s/foo/bar echo echo "bar foo" echo bar foo $ echo "foo foo" foo foo $ echo !!:gs/foo/bar echo echo "bar bar" echo bar bar

hiroaki 14y ago

$ !! runs the previous command. This is especially useful: $ !! $ sudo !!