Comments in command-line Zsh

137

votes

I switched quite recently from Bash to Zsh on Ubuntu and I'm quite happy about it. However, there is something I really miss and I did not find how to achieve the same thing.

In Bash, whenever I was typing a long command and noticed I had to run something else before, I just had to comment it out like in the following:

me@home> #mysuperlongcommand with some arguments
me@home> thecommandIhavetorunfirst #and then: then up up
me@home> #mysuperlongcommand with some arguments #I just need to uncomment it!

However, this quite recurrent situation is not as easy to address as with zsh, given #mysuperlongcommand will be run as such (and resulting in: zsh: command not found: #mysuperlongcommand.

command-linezsh

198

votes

Having just started trying out zsh, I ran into this problem too. You can do setopt interactivecomments to activate the bash-style comments.

43

votes

I use

bindkey "^Q" push-input

From the zsh manual:

Push the entire current multiline construct onto the buffer stack and return to the top-level (PS1) prompt. If the current parser construct is only a single line, this is exactly like push-line. Next time the editor starts up or is popped with get-line, the construct will be popped off the top of the buffer stack and loaded into the editing buffer.

So it looks like this:

> long command
Ctrl+Q => long command disappears to the stack
> forgotten command
long command reappears from stack
> long command

Also, if you set the INTERACTIVE_COMMENTS option (setopt INTERACTIVE_COMMENTS), you will be able to use comments in interactive shells like you are used to.

20

votes

I find myself doing this often as well. What I do is cut the long command, execute the command that needs to go first and then paste the long command back in. This is easy: CTRL+U cuts the current command into a buffer, CTRL+Y pastes it. Works in zsh and bash.

0

votes

In addition to setopt interactivecomments, suggested by @Lajnold, you might also want to add something like the following to prevent certain comments from being written to history (from https://superuser.com/questions/352788/how-to-prevent-a-command-in-the-zshell-from-being-saved-into-history):

This overrides the ZSH built-in function zshaddhistory():

Will log comments that start in column 1 not followed by one or more spaces (i.e. #somecommand that I want to come back to)
Won't log comments that start in column 1 followed by one or more spaces
Won't log indented comments, padded by spaces from column 1
Won't log commands with a space in column 1 (handy shortcut for running commands that you don't want logged

setopt interactivecomments

function zshaddhistory() {
  emulate -L zsh
  if ! [[ "$1" =~ "(^#\s+|^\s+#|^ )" ]] ; then
      print -sr -- "${1%%$'\n'}"
      fc -p
  else
      return 1
  fi
}

For reference, this is the default zshaddhistory() http://zsh.sourceforge.net/Doc/Release/Functions.html

zshaddhistory() {
  print -sr -- ${1%%$'\n'}
  fc -p .zsh_local_history
}

0

votes

: sh generate_sample.sh arg1

The addition of ":" doesn't execute the command in zsh.

sh generate_sample.sh : arg1

Now the arg1 is commented.

I am on Mac OS Big Sur and used it multiple times.

Edit: ":" procedure works with giving no spaces. ": command" is correct but ":command" isn't

Comments in command-line Zsh

5 Answers