Take the 2-minute tour ×
Super User is a question and answer site for computer enthusiasts and power users. It's 100% free, no registration required.

I am running OS X. On vim, if you do the :sh command, you can drop to a shell to execute commands. I constantly forget whether I am in this shell or not.

Is there any way to check if I am in the shell coming from vim?

share|improve this question

4 Answers 4

up vote 12 down vote accepted

env | grep vim lists environment variables that vim passes to your shell. I doubt VIMRUNTIME is defined if you haven't started your shell from vim.

share|improve this answer
2  
Awesome, this worked. I simply set it up to display {vim} in my PS1 if VIMRUNTIME is defined. Thanks! –  Wuffers Oct 17 '10 at 17:39
    
Thanks! This is exactly what I was looking for :) –  nornagon May 10 '12 at 2:20

I type ps (without any options) and see if vim is listed.

share|improve this answer
    
at least use pstree, if there is more than one instance of vim. –  Benoit Oct 17 '10 at 17:16
    
@Benoit: ps alone should be sufficient because by default it shows only those processes associated with the current terminal. At least that's the case on the Unix systems I use. –  garyjohn Oct 17 '10 at 17:29

You can look at the command name of the shell's parent process: ps -o comm= -p $PPID. You could for example change your prompt to include the parent process id.

Furthermore, if you only want to change your prompt in shells that are not running directly inside a terminal emulator, you can test this by checking whether the shell's controlling terminal is the same as its parent process's. If the parent is a terminal emulator, it won't have its own terminal as a controlling terminal.

For example, if you put the following lines in your ~/.kshrc or ~/.bashrc or ~/.zshrc (pick the one appropriate for your shell), your prompt will begin with {vim} if the shell is running under vim:

parent_command=$(ps -o comm= -p $PPID)
parent_command=${parent_command##*/}
if [ "$(ps -o tty= -p $$)" = "$(ps -o tty= -p $PPID)" ]; then
  # Not running directly under a terminal emulator
  PS1="{$parent_command}$PS1"
fi

You may also be interested in some of the discussion on How to know the “level” of shells I am in?.

share|improve this answer
    
Whenever I do this, and I am in the vim shell, I get {%cpu} instead of {vim}. And If I'm not in vim, I get errors at login. –  Wuffers Oct 17 '10 at 17:35
    
@Mr. Man: What I wrote should work under any POSIX-compliant OS (-o cmd= means not to display a header line, but getting %cpu means that ps did show a header line). However ps differs a lot between platforms, maybe yours isn't 100% compliant. What OS is it? –  Gilles Oct 17 '10 at 17:41
    
I am running Mac OS X. And, if it matters, I am using the provided Terminal.app. –  Wuffers Oct 17 '10 at 18:02
    
@Mr. Man: My mistake, the comm column is standard (and documented on OSX) but cmd isn't. You might still need $(ps -o comm= -p $PPID | tail -n 1) on OSX ≤10.4. –  Gilles Oct 17 '10 at 18:27
    
Thanks, that fixed the errors, but now when I am in the vim shell, it only shows {} instead of {vim}. –  Wuffers Oct 17 '10 at 18:32

You could use MacVim (http://code.google.com/p/macvim/). Whether or not your shell came from a vim instance becomes pretty obviously since your shell is in a MacVim window and not a Terminal window.

share|improve this answer

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.