Re: Alias for subcommands

[Jörg Sommer <joerg@xxxxxxxx>]

Bart Schaefer schrieb am Sa 19. Jun, 00:23 (-0700):
> On Fri, Jun 18, 2021 at 11:14 PM Jörg Sommer <joerg@xxxxxxxx> wrote:
> >
> > would it be possible to have aliases for subcommands?
> 
> It's not really possible to have aliases for multiple-word constructs,
> but you can create a function that "knows about" subcommands and then
> alias the base command to pass through that function.
> 
> Very roughly (on the fly, certainly needs work, likely better naming):
> 
> use_subcommand_aliases() {
>   local -a subcommand_expansion
>   zstyle -a subcommand_alias:$1 $2 subcommand_expansion &&
>     argv[2]=($subcommand_expansion)
>   "$@"
> }
> alias restic="use_subcommand_aliases restic"
> zstyle subcommand_alias:restic mount mount --allow-other
> --no-default-permissions

Thanks! This was a pretty good start. But some of the cases I couldn't
complete. Maybe you could help.

```
#!/bin/zsh -fuC

_subalias_expand() {
  local -a expansion

  if zstyle -a subalias:$1 $2 expansion
  then
    shift
    argv[1]=( $expansion )
  fi

  "$@"
}

subalias() {
    local full=false

    case $1 in
      -f) full=true; shift;;
    esac

    local cmd=$1
    shift

    if [[ $1 == *=* ]]
    then
        local subcmd=${1%%=*}
        argv[1]=${1#*=}
        if $full
        then
            zstyle subalias:$cmd $subcmd $@
        else
            zstyle subalias:$cmd $subcmd $cmd $@
        fi
        alias $cmd="_subalias_expand $cmd"
    else
        local -a expansion
        if zstyle -a subalias:$cmd $1 expansion
        then
            echo "$cmd $1=$expansion"
        else
            return 1
        fi
    fi
}

test_helper() {
    if [[ "$expect" != "$*" ]]
    then
        echo "failed: $*"
        exit 1
    fi
}

# simple test
expect=(mount)
subalias test_helper mnt=mount
if [[ "test_helper mnt=mount" != "$(subalias test_helper mnt)" ]]
then
    echo "subalias not defined: $(subalias test_helper mnt)"
fi
test_helper mnt

# call with args
expect=(mount -a --verbose ccc)
subalias test_helper mnt=mount
test_helper mnt -a --verbose ccc

# with same name
expect=(mount)
subalias test_helper mount=mount
if [[ "test_helper mount=mount" != "$(subalias test_helper mount)" ]]
then
    echo "subalias not defined: $(subalias test_helper mount)"
fi
test_helper mount

# alias with args
expect=(mount -a --verbose ccc -x)
subalias test_helper mnt=mount -a --verbose ccc
test_helper mnt -x

# alias with empty args
expect=(commit -m '')
subalias test_helper cc=commit -m ''
if [[ "test_helper cc=commit -m " != "$(subalias test_helper cc)" ]]
then
    echo "subalias not defined: $(subalias test_helper cc)"
fi
test_helper cc

# check run-help still works
hit=false
run-help-test_helper() {
    hit=true
}
echo 'TODO: How to test this???'

# full replace
test_helper_full() {
    if [[ "cmd --arg1 arg2" != "$*" ]]
    then
        echo "failed: $*"
    fi
    if [[ $EDITOR != /bin/true ]]
    then
        echo "failed EDITOR: $EDITOR"
    fi
}

subalias -f test_helper_full al=EDITOR=/bin/true test_helper_full cmd --arg1 arg2
if [[ "test_helper_full al=EDITOR=/bin/true test_helper_full cmd --arg1 arg2" != "$(subalias test_helper_full al)" ]]
then
    echo "subalias not defined: $(subalias test_helper_full al)"
fi
test_helper_full al
```

Regards Jörg

-- 
Die beste Tarnung ist die Wahrheit. Die glaubt einem keiner!
                      (Max Frisch: „Biedermann und die Brandstifter“)

Attachment: signature.asc
Description: PGP signature