I typed a very long command on the command line – only to discover that Bash doesn't like embedded single quotes. It is a bare tty and my only way to save this command for running from within a file is to open vim and start typing this very long command again...
Isn't there a shortcut to fire up vim on the text typed on the command line – directly from the command line?
Sure there is. The following command will edit the current command-line in $VISUAL:
C-x C-e
I found the answer for my case here:
First off a warning from #marlar (I made myself a function to protect myself
from this, see below):
Be very careful with this feature. If you cancel the edit, the original
command line will be immediately executed. So if you are editing rm -rf
<forward slash> and invoke the editor and realize you are into something
dangerous and thus cancel the edit, your root file system will be deleted
without further questions asked.
From the OP #Kartik:
The bash man page says:
edit-and-execute-command (C-xC-e)
Invoke an editor on the current command line, and execute the
result as shell commands. Bash attempts to invoke $VISUAL,
$EDITOR, and emacs as the editor, in that order.
And from #Mark E. Haase
If you use Bash's vi mode, the short cut is Esc, V...
I actually also find that doing just v is sufficient to launch vim with the bash
command sitting there.
From #karlicoss:
if your editor is vim, you can use :cq, it makes it exit with non-zero code,
and prevents the command from execution
Because I'm paranoid about the rm -rf command (I once deleted 2Tb of brain
data with that - 10 days into switching to linux... lucky the sysadmin had a
backup... actual quote: "I've never seen anything that stupid in my 20 years
doing this job"... but I digress) I put the following in my vimrc to
immediately comment out the command if I accidentally bring up vim and
reflexively exit:
function! CheckBashEdit()
" if the file matches this highly specific reg exp, comment the line
"(e.g. a file that looks like: /tmp/bash-fc.xxxxxx)
if match(#%, "\/tmp\/bash-fc\.......") != -1
" comment out the command
silent! execute ":%normal! I# "
write
endif
endfunction
" if we ended up in vim by pressing <ESC-v>, put a # at the beggining of
" the line to prevent accidental execution (since bash will execute no
" matter what! Imagine rm -rf <forward slash> was there...)
autocmd BufReadPost * :call CheckBashEdit()
There seems to be quite a lot of information on how to edit and execute a command using your editor using "edit-and-execute-command (C-x C-e)", but what I would like to achieve is take the current shell command, apply certain filtering (using a script) and then return it to prompt for further approval/manual changes before execution. Is this possible with bash?
Latest update based on my experience
The part 0"+y$dd in the following mapping is really something that you should carefully think about and tailor it to your taste/workflow/experience.
For instance, very frequently I've found myself ending up with multiple lines in the buffer, where I only want to execute the one the cursor is on; in this case I can use 0"+y$dd:%d<CR> instead of 0"+y$dd.
And this is just one of the possible scenarios.
Final answer for those who like vim
Set vim as your EDITOR/VISUAL, so that when editing a command line, you will use vim to edit it.
Put au BufEnter /tmp/bash-fc.* nn <Leader>d 0"+y$dd:wq<CR> in your ~/.vimrc file to map Leaderd (which you will rarely use when editing a command) to the action "delete the current line into the + register without the trailing EOL".
you can use either the + or the * register in the mapping above; the ways to paste into the terminal will likely differ; you need the +clipboard option for these registers to be available.
When finished editing a command in the vim editor, hit EscapeLeaderd.
Paste the clipboard into the terminal (this is terminal-dependent).
Original answer
I often need to do the same, and I do it as follows. (I normally use the set -o vi in bash, so points 1 and 2 in the following are different if you use set -o emacs, the default; based on your question it looks like points 1 and 2 are unified in Ctrl+x followed by Ctrl+e, which is harder to type, imho.)
hit Escape to be in normal mode,
hit v to enter the editor to edit the command,
edit the command as I like,
(This is where you ask the question.)
hit Escape0"+y$dd:wq,
Note: 0"+y$, not simply "+yy, as the latter would copy the newline too, and this would result in executing the command upon pasting it in the command line,
paste the clipboard on the command line
how to do this depends on the terminal you are using, I guess; I hit Ctrl+Alt+v in URxvt.
proceed to approval/manual edit.
Clearly this is just a workaround, consisting in copying the edited command into the clipboard before deleting the whole command, so that nothing gets executed upon exiting the editor; however it's the best I can get for myself.
Update
As my EDITOR (and VISUAL) is equal to vim, when I edit the command, I edit it in vim.
In this respect, I have noticed that the buffer is named /tmp/bash-fc.random, where random is a 6-characters alphanumeric random string.
This gives space to a lot of possiblities, if you use vim as your editor, as you can define some mapping in your .vimrc to execute the whole sequence Escape0"+y$dd:wq. For instance, one command that you'd rarely use when editing a command line is Leaderd; therefore you can put the following mapping in your .vimrc file
au BufEnter /tmp/bash-fc.* nn <Leader>d 0"+y$dd:wq<CR>
so that step 4 in the above recipe becomes
hit EscapeLeaderd
It's not possible to do that in Bash/readline but it's possible in zsh
using edit-command-line command:
darkstar% autoload edit-command-line; zle -N edit-command-line
darkstar% bindkey "^X^E" edit-command-line
Now press Control-x Control-e to open your editor, edit line, leave the editor - you will see the updated command line but it will not be executed automatically.
Now that I think about it, maybe a variation of what #kenorb suggested in a comment is the best workaround (as it seems no solution exists), if we want to stick to bash.
What you can do is prepend a # (the comment character in bash) to the command, rather than echo. Then when you exit the editor, the command will be ineffective, and you will only have to press arrow up (or k, if you use set -o vi), remove the # and confirming.
Note that this strategy adds just a few keystrokes, so it can be fairly efficient, depending on your typing level.
These pieces might get you closer:
a) replace the the normal binding for newline newline (ctrl-M)
bind -x '"\C-M":date"
b) grab the current line from the history using !#
replace date with whatever script you want.
c) edit manually
d) if necessary, somehow tie in !!:p which prints the new command to the command line but does not execute it, thus letting you manually edit it.
e) using ctrl-J submit edited command rather than a newline
or they might not ....
There is an option in bash to modify command from history without executing it. I'm not sure it it's possible to use script for this, doesn't seem to be likely. Although, you can make modifications using history modifiers.
Enable option histverify to prevent execution of modified command
Use chain of modifiers to change last command
Use "!!" to put your result to command line for final edit
Here is how it looks:
$ shopt -s histverify
$ ls *.sh
script1.sh script2.sh script3.sh script-return.sh
$ !!:s/*/script1/:p
ls script1.sh
$ !!:s/1/2/:p
ls script2.sh
$ !!
$ ls script2.sh
script2.sh
I'd like to point you to the Composure framework for Bash (I'm not affiliated with it): https://github.com/erichs/composure
It provides draft and revise functions that sound like they could help with what you're trying to do. Here's a (long) quote from the project's readme file:
Composure helps by letting you quickly draft simple shell functions,
breaking down your long pipe filters and complex commands into
readable and reusable chunks.
Draft first, ask questions later
Once you've crafted your gem of a command, don't throw it away! Use
draft () and give it a good name. This stores your last command as a
function you can reuse later. Think of it like a rough draft.
$ cat servers.txt
bashful: up
doc: down
up-arrow
$ cat servers.txt | grep down
doc: down
$ draft finddown
$ finddown | mail -s "down server(s)" admin#here.com
Revise, revise, revise!
Now that you've got a minimal shell function, you may want to make it
better through refactoring and revision. Use the revise () command
to revise your shell function in your favorite editor.
generalize functions with input parameters
add or remove functionality
add supporting metadata for documentation
$ revise finddown
finddown ()
{
about finds servers marked 'down' in text file
group admin
cat $1 | grep down
}
$ finddown servers.txt
doc: down
It does not seem possible with a keyboard shortcut, at least:
$ bind -P | grep -e command -e edit
complete-command can be found on "\e!".
edit-and-execute-command can be found on "\C-x\C-e".
emacs-editing-mode is not bound to any keys
possible-command-completions can be found on "\C-x!".
vi-editing-mode is not bound to any keys
This can be done in native bash using readline specifically READLINE_LINE and READLINE_POINT variables. I use this functionality all the time though not through vim, you would need to get the value of $selected from your vim command and if not empty it takes your original line + your input and replaces your original line with the combination without executing. output as a variable
_main() {
selected="$(__coms_select__ "$#")"
origonal_text=$READLINE_LINE READLINE_LINE="${READLINE_LINE:0:$READLINE_POINT}$selected${READLINE_LINE:$READLINE_POINT}"
READLINE_POINT=$(( READLINE_POINT + ${#selected} ))
}
bind -m emacs-standard -x '"\C-e": _main '
bind -m vi-command -x '"\C-e": _main '
bind -m vi-insert -x '"\C-e": _main '
Edit
Just remembered these two utilities that will let you do this as well.
Vipe allows you to run your editor in the middle of a unix pipeline and edit the data that is being piped between programs.
vp, up, vipe, Neomux (upgrade of nvim terminal) you can do some pretty neat throwing buffers between the terminal and split window.
and Athame (full vim on the command line)
https://github.com/ardagnir/athame
careful with that one though plugins work on the cli and it can get funky if you got tons of plugins
Some times that I have a command ready to press enter but that command I have changed it in some way and it's a long command, then I remember that I have to open a text file (e.g. to get some information that I will use in the command). So what most of the times I do, is to cancel that command (Ctrl+C) and then open the text file get the information I need and then retype the command again with the pasted value from the text file. This is not very efficient for me specially if the server doesn't have any kind of GUI and I can't copy the previous command so I don't lose it.
So my question is, Is there any kind of combination keys that I could use to save a command ready to enter so I don't lose it and I don't have to type it all over again?
Thanks!
This is currently not possible out of the box.
The easiest way to do it is probably to
Change the cancel binding to stash the commandline
Add a binding to recall the stashed commandline
It would work something like this:
The function to recall:
function recall_commandline
if set -q stashed_commandline
commandline -r -- $stashed_commandline
end
end
Add to __fish_cancel_commandline (use funced __fish_cancel_commandline. Once you are happy do funcsave __fish_cancel_commandline):
set -g stashed_commandline $cmd
# right before:
commandline ""
Add to fish_user_key_bindings
bind \cr recall_commandline
This will allow you to press Ctrl+r to recall the last cancelled commandline. Expanding it to multiple is non-trivial (since "commandlines" can have multiple lines), as is adding the commandlines to history so that they can be recalled with the normal bindings.
I have the following function to turn comment/uncomment the current statement:
function toggle-comment-cmd-buffer --description 'Comment/Uncomment the current or every line'
set -l cmdlines (commandline -b)
if test "$cmdlines" = ""
return
end
set -l cmdlines (printf '%s\n' '#'$cmdlines | string replace -r '^##' '')
commandline -r $cmdlines
string match -q '#*' $cmdlines[1]; and commandline -f execute
end
I bind it thusly: bind \e\# toggle-comment-cmd-buffer. This way I can quickly comment and put the current statement in my command history in order to do something else. Then I can recall the comment and press [alt-#] again to remove the comment characters and continue modifying the command.
I set this up in my personal fish config because I had gotten used to doing something similar in ksh93.
I am using fish shell. When I type Ctrl-D, it sends a EOF to my terminal and then terminal closes.
I want to make it such that ctrl-D does not close my iterm2.
I saw that people have set up IGNOREEOF in bash shell like this: https://unix.stackexchange.com/questions/27588/how-can-i-keep-controld-from-disconnecting-my-session
However, I don't think this variable exists in fish. Does anybody know how I can force iterm2(with default fish shell) to not close on ctrl-D?
This is the default key binding for control-D:
bind \cd delete-or-exit
you can find this by just running bind.
(delete-or-exit is just a function, which you can read with functions delete-or-exit.)
So it's exiting because that's what the default behavior is. You can make control-D do something else. For example, maybe it should delete the character under the cursor:
bind \cd delete-char
If you want to make this permanent, add it to your fish_user_key_bindings function:
Run funced fish_user_key_bindings which starts editing
Put bind \cd delete-char within the function
Hit return to create the function
Run funcsave fish_user_key_bindings to save it
Shell approach
After reading this question and answer I updated my delete-or-exit function to ask for confirmation rather than completely deactivate it:
cd ~/.config/fish/functions/
cp /usr/share/fish/functions/delete-or-exit.fish .
Then edit/replace:
function delete-or-exit
set -l cmd (commandline)
switch "$cmd"
case ''
read --nchars 1 --local -P 'Do you want to exit? [y/N] ' confirm
switch $confirm
case Y y
exit 0
case '' N n
echo -n (fish_prompt)
end
case '*'
commandline -f delete-char
end
end
It has a minor issue in that it displays the prompt twice when you finish, but it seems better than no times if you don't print it (see N case above). Perhaps someone has a solution to that.
Terminal approach
iTerm and many other terminals have a setting says something like, "keep terminal open when program exits."
Instead of assigning a different action to Ctrl+d you could also unbind it through bind --erase --preset \cd. With all steps:
Run funced fish_user_key_bindings which starts editing
Put bind --erase --preset \cd within the function
Hit return to create the function
Run funcsave fish_user_key_bindings to save it
I am creating a journal application for personal notes and have the following in my Rakefile:
task :new do
entry_name = "Entries/#{Time.now.to_s.gsub(/[-\ :]+/, '.').gsub(/.0500+/,'')}.md"
`touch #{entry_name}`
`echo "# $(date)" >> #{entry_name}`
end
The last part I would like to include is the opening of the Vim text editor but I am unable to figure out how to open it as if I called it directly from the bash terminal.
I have tried:
vim #{entry_name}
but unfortunately I think both of those open it as a background process.
I have been referencing "6 Ways to Run Shell Commands in Ruby".
As in the article you referenced, `s run the command in a subshell within the current process, but the real problem is that it's trying to take the output from the command run as well, which doesn't play nice with Vim.
You can either:
Use exec to replace the current process with the new one (note that the Ruby/Rake process will end once you've called exec, and nothing after it will run).
Use system to create a subshell like `s, but avoids the problem of trying to grab Vim's stdout. Unlike exec, after Vim terminates, Ruby will continue.
you need to pass the tty as standard input for backspaces etc. to work well in vim:
exec("</dev/tty vim a b")
obviously the backtick (`) didn't work but I was having issues with system/exec from a script.
first I get Vim: Warning: Input is not from a terminal, and then I see ^? when I use backspace.