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how to re-use existing completion with recent bash-completion? [Resolved]

i use alias which adds some parameters to some program.

for example:

alias git.home='git --git-dir=$HOME/.git.home/'

complete -o bashdefault -o default -o nospace -F _git git.home \
  2>/dev/null || complete -o default -o nospace -F _git git.home

it works with bash-completion v.1:2.0-1 ("debian 7 wheezy"):
tab completes parameters and options for alias git.home as well as for "original" git.

but with bash-completion v.1:2.1-4 ("debian 8 jessie") after typing git.home and pressing tab i get this error:

bash: completion: function `_git' not found

how to re-use existing completion (for example for git) with recent versions of package bash-completion?


update

found partial solution: do source /usr/share/bash-completion/completions/git before complete ...

but i get another error - git.home log + space + tab results in:

fatal: Not a git repository (or any of the parent directories): .git HEAD


Question Credit: alexander barakin
Question Reference
Asked January 11, 2019
Posted Under: Unix Linux
54 views
2 Answers

updated

solution for alias git.home, which operates with ~/.git.home as repo.

partially based on this answer.

add to ~/.bashrc:

alias git.home='git --git-dir=$HOME/.git.home/'

_completion_loader git
eval "$(complete -p git | sed -r 's/(\s)git$/\1git.home/')"

eval "$(type __gitdir | 
  sed '1d;1,/if/s|if|if [[ "$COMP_LINE" == "git.home "* ]]; then\necho "$HOME/.git.home"\nelif|')"

explanation of last eval (for other lines see answer):

we are patching the function __gitdir(), which returns a path to the git repo dir. from:

$ type __gitdir | head -n 4
__gitdir is a function
__gitdir () 
{ 
    if [ -z "${1-}" ]; then

to:

$ type __gitdir | head -n 7
__gitdir is a function
__gitdir () 
{ 
    if [[ "$COMP_LINE" == "git.home "* ]]; then
        echo "$HOME/.git.home";
    else
        if [ -z "${1-}" ]; then

i.e., if command starts with a "git.home ", function returns $HOME/.git.home.


credit: Community
Answered January 11, 2019

how to re-use existing completion (for example for git) with recent versions of package bash-completion

Add the following lines to your ~/.bashrc:

_completion_loader git
eval $(complete -p git | perl -pe 's/(\s)git$/$1git.home/')

Explanation:

bash-completion uses a dynamic loading of completions since 1.90. So, the git compspec unavailable before your typing git,Space,Tab.

Try:

bash
complete -p git # bash: complete: git: no completion specification
git<space><tab>
complete -p git # complete -o bashdefault -o default -o nospace -F __git_wrap__git_main git

_completion_loader git imitates git,Space,Tab (i.e. loads a compspec for git)

complete -p git | perl -pe 's/(\s)git$/$1git.home/' builds a compspec for git.home (replaces git to git.home in a git's compspec)

eval execute the resulting compspec.

Type git.home,Space,pTab. You should see:

popt   pull   push

But git.home log,Space,Tab produces:

fatal: Not a git repository (or any of the parent directories): .git HEAD

This message is a result of the git completion bug. There is a fix in the upstream: completion: silence "fatal: Not a git repository" error

Looks like another question:)

_githome(){ 
   GIT_DIR=$HOME/.git.home
   complete -o default -o nospace -F _git git.home
 }

doesn't work as expected. You set GIT_DIR for current session. Try with your solution:

bash
git clone git://git.debian.org/git/bash-completion/bash-completion.git ~/bash-completion
cd ~/bash-completion
git log<space><tab> # completion for current repo
git.home log<space><tab> # completion for GIT_DIR
git log<space><tab> # completion for GIT_DIR

credit: Stephen Kitt
Answered January 11, 2019
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