Bash – nyway to get COMPREPLY to be output as a vertical list of words instead in a single line

autocompletebash

COMPREPLY by default returns a space separated list of words, but I'd like to have it return a single word per line. I've tried putting newlines at the ends of the words and have looked through the docs for both compgen and complete but can't find anything.

Is this possible?

EDIT:

Sorry I really explained that poorly. I have a script that is bound to an autocomplete function via complete -F. When the user runs the script, hitting tab twice will show a list of possible options via compgen. Right now the function has lines of code like this:

COMPREPLY=( $(compgen -W '$( ls ~/work/dev/jobs/ | cat )' -- $curword ) )

When the user hits tab though, these directories are displayed like:

directory0 directory1 directory2 directory3

but i would like them displayed like:

directory0
directory1
directory2
directory3

I posted a similar thread to /r/bash and someone suggested doing

bind 'set completion-display-width 0'

which works, and then I can unset it with

bind 'set completion-display-width -1'

The issue now is that if I unset it before the complete function returns, it has no effect, so I unset it in the script after the user has pressed enter. This works fine, but if the user starts using the autocomplete, and then changes their mind and delets what they had entered and were to return to the shell, completion-display-width would still be set to 0.

Is there another way to go about this?

Best Answer

I'm the one that suggested changing the completion-display-width readline variable at /r/bash, but then you didn't specify you only wanted it to work on this one completion function.

Anyway, in a completion function, you can detect whether it's triggered by TAB (COMP_TYPE == 9) or by TABTAB (COMP_TYPE == 63), and if the latter is the case, you could pad the results with spaces so they fill the entire width of the terminal. It's the least hackish thing I can think of. It would look something like this:

_foo_complete() {
    local i file files
    files=( ~/work/dev/jobs/"$2"* )
    [[ -e ${files[0]} || -L ${files[0]} ]] || return 0
    if (( COMP_TYPE == 63 )); then
        for file in "${files[@]}"; do
            printf -v 'COMPREPLY[i++]' '%*s' "-$COLUMNS" "${file##*/}"
        done
    else
        COMPREPLY=( "${files[@]##*/}" )
    fi
}
complete -F _foo_complete foo

On a side note, you really shouldn't parse ls output.

Related Solutions

Bash – Custom autocomplete: deal with spaces in filenames

Believe it might be better to use compgen instead of find in this case.

You probably already have a completion script with system. Try e.g.

locate bash_completion

On Debian variants this is probably:

/usr/share/bash-completion/bash_completion

where you find e.g. _filedir. So the simplest way then would be something in the direction of:

*)
    pushd "/some/path" >/dev/null
    _filedir
    popd >/dev/null

If that is not an option this could be a starter:

_comp_by_path()
{
    local opt cur dir
    local IFS=$'\n' x tmp
    local -a tokens

    opt="$1"
    cur="$2"
    dir="$3"

    # Enter target directory
    pushd "$dir" >/dev/null

    # Get directories, filtered against current
    [[ "$opt" != "-f" ]] && \
    x=$( compgen -d -- "$cur" ) &&
    while read -r tmp; do
        tokens+=( "$tmp" )
    done <<< "$x"

    # Get files, filtered against current
    [[ "$opt" != "-d" ]] && \
    x=$( compgen -f -- "$cur" ) &&
    while read -r tmp; do
        tokens+=( "$tmp" )
    done <<< "$x"

    # If anything found
    if [[ ${#tokens[@]} -ne 0 ]]; then
        # Make sure escaping is OK
        compopt -o filenames 2>/dev/null
        COMPREPLY+=( "${tokens[@]}" )
    fi

    # Go back
    popd >/dev/null
}

_GetOptMyCommand()
{
    local cur

    COMPREPLY=()
    cur="${COMP_WORDS[COMP_CWORD]}"

    case "$cur" in
    -*)
        COMPREPLY=( $( compgen -W "-h -l --help --list --" -- "$cur" ) );;
    *)
        _comp_by_path "any" "$cur" "/some/path"
    esac
}

complete -F _GetOptMyCommand my_command

A variant using find could be something in direction of this:

_zaso()
{
    local dir="$1"

    pushd "$dir" >/dev/null
    find * -maxdepth 0 2>/dev/null
    popd >/dev/null
}

_comp_with_find()
{
    local cur dir      
    local IFS=$'\n'

    cur="$1"
    dir="$2"

    compopt -o filenames 2>/dev/null
    COMPREPLY=( $( compgen -W "$(_zaso "$dir")" -- "$cur" ) );
}

Also note that printf in Bash has a %q option. So to generate quoted strings this is an option to play with:

find * -maxdepth 0 2>/dev/null && \
while read -r tmp; do
    printf "%q\n" "$tmp"
done <<< "$x"

Also not that file names can have newline characters in which a lot of this will break. Have not found a way to use \0 with compgen.

Bash – Is there a way to customize “Programmable Completion” in the current session

In the bash_completion mechanism it's the bash function _filedir_xspec() that is responsible for filename and dirname completions. This funtion can be found in the script /etc/bash_completion.

You can edit that function and add a line that contains your regex. For example use this function (it's a copy of the original function):

_filedir_xspec()
{
    local IFS cur xspec

    IFS=$'\n'
    COMPREPLY=()
    _get_comp_words_by_ref cur

    _expand || return 0

    # get first exclusion compspec that matches this command
    xspec=$( awk "/^complete[ \t]+.*[ \t]${1##*/}([ \t]|\$)/ { print \$0; exit }" \
        "$BASH_COMPLETION" )
    # prune to leave nothing but the -X spec
    xspec=${xspec#*-X }
    xspec=${xspec%% *}

    local -a toks
    local tmp

    toks=( ${toks[@]-} $(
        compgen -d -- "$(quote_readline "$cur")" | {
        while read -r tmp; do
            # see long TODO comment in _filedir() --David
            printf '%s\n' $tmp
        done
        }
        ))

    # Munge xspec to contain uppercase version too
    eval xspec="${xspec}"
    eval xspec="!*.txt" #<---- HERE add your regex, that's the only line changed
    local matchop=!
    if [[ $xspec == !* ]]; then
        xspec=${xspec#!}
        matchop=@
    fi
    [[ ${BASH_VERSINFO[0]} -ge 4 ]] && \
        xspec="$matchop($xspec|${xspec^^})" || \
        xspec="$matchop($xspec|$(printf %s $xspec | tr '[:lower:]' '[:upper:]'))"

    toks=( ${toks[@]-} $(
        eval compgen -f -X "!$xspec" -- "\$(quote_readline "\$cur")" | {
        while read -r tmp; do
            [ -n $tmp ] && printf '%s\n' $tmp
        done
        }
        ))
    [ ${#toks[@]} -ne 0 ] && _compopt_o_filenames
    COMPREPLY=( "${toks[@]}" )
}

Notice the new part at line 32:

eval xspec="!*.txt"

This statement is later used in compgen to remove all entries, that do not match the regular expression. I wouldn't recommend to edit the file /etc/bash_completion. Instead make a new file with the content above and source the file if needed:

source /path/to/file

Now, all commands/applications in the shell, that where completed by the function _filedir_xspec(), complete now only with *.txt filenames.

Best Answer

Related Solutions

Bash – Custom autocomplete: deal with spaces in filenames

Bash – Is there a way to customize “Programmable Completion” in the current session

Related Question