Question

3

Shell gives no prompt if auto completion is enabled (blinking cursor instead)

rated 0 times [ 3] [ 0] / answers: 1 / hits: 1087 / 3 Years ago, thu, july 29, 2021, 6:25:24

I tryed to enable shell autocompletion uncommenting the following lines in my .bashrc:

# enable programmable completion features (you don't need to enable

# this, if it's already enabled in /etc/bash.bashrc and /etc/profile

# sources /etc/bash.bashrc).

 if ! shopt -oq posix; then

   if [ -f /usr/share/bash-completion/bash_completion ]; then

     . /usr/share/bash-completion/bash_completion

   elif [ -f /etc/bash_completion ]; then

     . /etc/bash_completion

   fi

 fi

However, this have a side effect. Even though autocomplete seems to work, when I open a new terminal, only a blinking cursor is presented:

enter image description here

I am returned to the usual user@machine:~$ prompt only after pressing Ctrl+C.

The normal behavior is restored if I comment the above lines (but no autocompletion any more).

I can't figure out what the problem is.

--Update 1--

Here's what the code does:

enter image description here

--Update 2--

Here's the output of the suggested commands. Somethings keeps looping and the terminal is flooded by the ouptut.

++++++ : /etc/bash_completion.d

++++++ readonly BASH_COMPLETION_COMPAT_DIR

++++++ _blacklist_glob='@(acroread.sh)'

++++++ shopt -s extglob progcomp

++++++ complete -d pushd

++++++ complete -u write chfn groups slay w sux runuser

++++++ complete -A stopped -P '"%' -S '"' bg

++++++ complete -j -P '"%' -S '"' fg jobs disown

++++++ complete -v readonly unset

++++++ complete -A setopt set

++++++ complete -A shopt shopt

++++++ complete -A helptopic help

++++++ complete -a unalias

++++++ complete -A binding bind

++++++ complete -c command type which

++++++ complete -b builtin

++++++ [[ linux-gnu == *@(solaris|aix)* ]]

++++++ [[ linux-gnu == *@(solaris|aix)* ]]

++++++ [[ linux-gnu == *@(solaris|aix)* ]]

++++++ _backup_glob='@(#*#|*@(~|.@(bak|orig|rej|swp|dpkg*|rpm@(orig|new|save))))'

++++++ complete -F _service service

++++++ _sysvdirs

++++++ sysvdirs=()

++++++ [[ -d /etc/rc.d/init.d ]]

++++++ [[ -d /etc/init.d ]]

++++++ sysvdirs+=(/etc/init.d)

++++++ [[ -f /etc/slackware-version ]]

++++++ for svcdir in '${sysvdirs[@]}'

++++++ for svc in '$svcdir/!($_backup_glob)'

++++++ [[ -x /etc/init.d/acpid ]]

++++++ complete -F _service /etc/init.d/acpid

++++++ for svc in '$svcdir/!($_backup_glob)'

++++++ [[ -x /etc/init.d/anacron ]]

++++++ complete -F _service /etc/init.d/anacron

++++++ for svc in '$svcdir/!($_backup_glob)'

++++++ [[ -x /etc/init.d/apparmor ]]

--Update 3--

Here's the requested output:

ac@ac:~$ grep -r bash_completion /etc/bash_completion.d

/etc/bash_completion.d/bash.bashrc:#  if [ -f /usr/share/bash-completion/bash_completion ]; then

/etc/bash_completion.d/bash.bashrc:#    . /usr/share/bash-completion/bash_completion

/etc/bash_completion.d/bash.bashrc:#  elif [ -f /etc/bash_completion ]; then

/etc/bash_completion.d/bash.bashrc:#    . /etc/bash_completion

/etc/bash_completion.d/bash.bashrc.bak:#  if [ -f /usr/share/bash-completion/bash_completion ]; then

/etc/bash_completion.d/bash.bashrc.bak:#    . /usr/share/bash-completion/bash_completion

/etc/bash_completion.d/bash.bashrc.bak:#  elif [ -f /etc/bash_completion ]; then

/etc/bash_completion.d/bash.bashrc.bak:#    . /etc/bash_completion

/etc/bash_completion.d/inkscape:# put this file in /etc/bash_completion.d/ 

/etc/bash_completion.d/desktop-file-validate:# put this file in /etc/bash_completion.d/

/etc/bash_completion.d/bash_completion~:. /usr/share/bash-completion/bash_completion

/etc/bash_completion.d/git-completion.bash:#   bash_completion - programmable completion functions for bash 3.2+

/etc/bash_completion.d/libreoffice.sh:# Programmable bash_completion file for the main office applications

/etc/bash_completion.d/bash_completion:# . /usr/share/bash-completion/bash_completion

Indeed the last line shows what you predicted.
But I don't know what to do with that file: should I delete it, or I mistakenly overwrote it?
If so, what was the original content?

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deringach

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answered 3 Years ago inciplyies · Accepted Answer

The fact that the output you get with set -x contains so many plus signs (++++++) means that /usr/share/bash-completion/bash_completion is being re-sourced recursively.

In other words, /usr/share/bash-completion/bash_completion is "calling" himself, resulting in a sort of infinite loop, as you noted.

If I were you, I would check /etc/bash_completion.d looking for references to /usr/share/bash-completion/bash_completion. Specifically, here is what I would do:

ls -l /etc/bash_completion.d (there must be no symlinks to /usr/share/bash-completion/bash_completion);

grep -r bash_completion /etc/bash_completion.d (none of the files in /etc/bash_completion.d should source /usr/share/bash-completion/bash_completion).

Alternatively, you can run these two commands in your shell (without bash completion enabled, of course):

set -x

. /usr/share/bash-completion/bash_completion |& grep -E "^++ (.|source)"

This will print all "imports" and will help us identify the nasty piece of code that is causing the problem.

From the output of grep -r bash_completion /etc/bash_completion.d you can see many matches. Most of them are comments (because they start with #), but there's an interesting line:

/etc/bash_completion.d/bash_completion~:. /usr/share/bash-completion/bash_completion

/etc/bash_completion.d/bash_completion~ is the culprit. This is the file that is causing the recoursive re-source.

/usr/share/bash-completion/bash_completion in fact automatically sources every file in the /etc/bash_completion.d directory. But this directory, in your case, contains the bash_completion~ file, which is sourcing /usr/share/bash-completion/bash_completion again. This results in the sort of loop that you are experiencing.

So go ahead and delete it!

sudo rm /etc/bash_completion.d/bash_completion~

(Or maybe read it if you believe it contains something useful.)

I cannot tell you why that file was in that directory. What I can tell you is that the suffix ~ means that this is a backup file. Many text editors (including Gedit) create backup copies upon saving. Probably it was left there by mistake while you were making changes.