This command: ". .bashrc" has resulted in: “-bash: /usr/bin/whoami: Argument list too long” whenever I try to execute any command

Question

While following instructions at a forum post to install something over ssh at an external machine, I executed the following command without thinking:

. .bashrc

I have never seen the command before but am guessing (from having had a similar problem previously) that it recursively sources ~/.bashrc because now I can't execute any commands. When I login, I can't do anything. I immediately get:

-bash: /usr/bin/whoami: Argument list too long
-bash: /usr/bin/cut: Argument list too long
-bash: /usr/bin/logger: Argument list too long 

Unfortunately, I can't do what solved the problem when I had a similar problem in the past (login without using the bash shell by doing ssh -t user@host /bin/sh and then modify ~/.bashrc) because there does not seem to be any problem with ~/.bashrc. It looks exactly the same as it did before I messed up.

Whatever I did, modifying ~/.bashrc does not appear to be a fix. Can anyone please suggest an alternative solution?

---

Here is ~/.bashrc:

# .bashrc
# Source global definitions
if [ -f /etc/bashrc ]; then
       . /etc/bashrc
fi

export PATH=$PATH:$HOME/.local/bin:$HOME/bin
export PATH=$PATH:$HOME/.local/bin:$HOME/bin/prog1:$PATH
export PATH=$PATH:$HOME/.local/bin:$HOME/bin/prog2:$PATH
export PATH=$PATH:$HOME/.local/bin:$HOME/prog2:$PATH
export PATH=$PATH:$HOME/.local/bin:$HOME/prog2/bin:$PATH
export PATH=$PATH:$HOME/.local/bin:$HOME/bin/prog3/tools/newtool:$PATH

export PYTHONPATH=$PATH:$HOME/.local/bin:$HOME/prog2:$PYTHONPATH

Answer 1

. .bashrc would run the contents of .bashrc in the current shell. Usually, you don't need to do that, since .bashrc is read by the shell when it starts, but if you make modifications to it and want to reload them, you might do that.

But doing that in one interactive shell shouldn't affect other shells you start on later logins.

---

What you have there in .bashrc, is somewhat odd, though:

export PATH=$PATH:$HOME/.local/bin:$HOME/bin/prog1:$PATH
            ^^^^^                                  ^^^^^

Note how you're putting the old $PATH to the start and end of the new PATH, five different times. By my count, that would put the original $PATH there 32 times. That's not too bad, but if that has been done when the shell starts, your $PATH would now be some thousands of characters, and if you then do the same thing again, it might end up being far longer than 100 kB. Starting with my $PATH of 74 chars, running those assignments twice gives a string of 172 kB.

And that might be a problem: Linux has limit of 128 kB for the length of a single command line argument (in addition to a limit for the whole lot). Environment variables and command line arguments are passed similarly on execve(), so presumably the same limit applies to both, and hence PATH.

Answer 2

Replace the first set of export lines with this

export PATH="$PATH:$HOME/.local/bin:$HOME/bin"
[[ -d "$HOME/bin/prog1" ]] && PATH="$PATH:$HOME/bin/prog1"
[[ -d "$HOME/bin/prog2" ]] && PATH="$PATH:$HOME/bin/prog2"
[[ -d "$HOME/prog2" ]] && PATH="$PATH:$HOME/prog2"
[[ -d "$HOME/prog2/bin" ]] && PATH="$PATH:$HOME/prog2/bin"
[[ -d "$HOME/bin/prog3/tools/newtool" ]] && PATH="$PATH:$HOME/bin/prog3/tools/newtool"

What was happening was that you were doubling up $PATH on every line ($PATH + new item + $PATH). Very strange.

In this replacement code each [[ ... ]] section ensures the corresponding directory exists before adding it to your $PATH. Not essential but certainly cleaner