如何为我的程序的一个子命令调用另一个程序的bash完成处理程序？

Question

上下文

我有一个名为arduino-cli包装器的ino脚本，它从以下位置读取目标/构建配置：

位于草图directory

• Command-line flags/arguments

中的

1. JSON文件

然后构造并exec相应的arduino-cli命令行。

问题

作为一个方便的包装脚本，ino并不打算支持arduino-cli的所有特性。因此，对于那些ino不自动执行的任务，用户可以使用ino的cli子命令间接调用ino。

例如，如果用户键入以下命令：

% ino cli update
% ino cli core list --all

ino脚本将获取cli后面的所有内容，并简单地将它们附加到arduino-cli可执行文件中。因此，它们相当于以下命令：

% arduino-cli update
% arduino-cli core list --all

由于arduino-cli对它的所有子命令和标志都有很好的bash完成，所以我想为我的ino cli子命令劫持相同的完成功能。

我试过的

1. 在这里接受的答案：

- [How do I autocomplete nested, multi-level subcommands?](https://stackoverflow.com/a/17881946/1054397)
- [Multi Level Bash Completion](https://stackoverflow.com/a/5303225/1054397) 
    - These helped me understand how to identify the current subcommand and discriminate the completion results based upon it.
    - However, I couldn't figure out how to then invoke the `arduino-cli` completion handler using the remaining args.

从接受的答案导出的

1. 完成处理程序：

- [How do I get bash completion for command aliases?](https://unix.stackexchange.com/a/4220/100385) 
    - See my `ino` completion handler based on that answer below (_Reference_ _**1**_).
    - This question/answer isn't quite the same, because they can basically just install a completion handler on their alias. I'm needing to "install" one _on an argument_ to a command/alias.
    - This almost seems to work. Try it with `xtrace` option enabled (`set -x`), and you can see the `arduino-cli` command-line is appearing in the args ... but following `ino` at position `$0`. 
        - E.g., given `ino cli core list --all` to the wrapper handler, the `arduino-cli` handler receives `ino arduino-cli core list --all`. Not sure how to get rid of `$0`!

参考文献

从基于别名的包装器派生的

• ino完成包装器

joinstr() {
    local d=${1-} f=${2-}
    shift 2 && printf %s "$f" "${@/#/$d}"
}

complete-subcmd() {
    [[ ${#} -gt 2 ]] || {
        printf "usage:\n\tcomplete-subcmd src-command... -- comp-func dst-command...\n"
        return 1
    }
    # parse the command-line by splitting it into two command-lines
    # of variable length, src-command and dst-command:
    #   1. src-command is the trigger that invokes the real completion
    #      handler, comp-func.
    #   2. dst-command is the leading args of the command-line passed
    #      to the real completion handler, comp-func, to produce the
    #      resulting completion choices.
    unset -v dstparse
    local -a srccmd dstcmd
    local func
    while [[ ${#} -gt 0 ]]; do
        case "${1}" in
        --) 
            # when we reach the delimiter, also shift in comp-func as 
            # the next argument (the real completion handler).
            dstparse=1
            shift
            func=${1:-}
            ;;
        *)
            # if we aren't processing the delimiter, then all other
            # args are appended to either src-command or dst-command.
            if [[ -z ${dstparse} ]]; then
                srccmd+=( "${1}" )
            else
                dstcmd+=( "${1}" )
            fi
            ;;
        esac
        shift
    done
    # if the completer is dynamic and not yet loaded, try to load it
    # automatically using the given command
    if [[ $( type -t "${func}" ) != function ]]; then
        type -p _completion_loader &> /dev/null &&
            _completion_loader "${dstcmd[@]}"
    fi
    local wrap=$( joinstr _ "${srccmd[@]}" | tr -d -c '[A-Za-z_]' )
    # replace our args with dst-command followed by whatever remains
    # from the invoking command-line.
    eval "
        function _${wrap} {
            (( COMP_CWORD+=$(( ${#dstcmd[@]} )) ))
            COMP_WORDS=( "${dstcmd[@]}" \${COMP_WORDS[@]:1} )
            "${func}"
            return 0
        }
    "
    # install this wrapper handler on the first word in src-command
    complete -F "_${wrap}" "${srccmd[0]}"
}

complete-subcmd ino cli -- __start_arduino-cli arduino-cli

• completion.bash来自arduino-cli

# bash completion V2 for arduino-cli                          -*- shell-script -*-

__arduino-cli_debug()
{
    if [[ -n ${BASH_COMP_DEBUG_FILE:-} ]]; then
        echo "$*" >> "${BASH_COMP_DEBUG_FILE}"
    fi
}

# Macs have bash3 for which the bash-completion package doesn't include
# _init_completion. This is a minimal version of that function.
__arduino-cli_init_completion()
{
    COMPREPLY=()
    _get_comp_words_by_ref "$@" cur prev words cword
}

# This function calls the arduino-cli program to obtain the completion
# results and the directive.  It fills the 'out' and 'directive' vars.
__arduino-cli_get_completion_results() {
    local requestComp lastParam lastChar args

    # Prepare the command to request completions for the program.
    # Calling ${words[0]} instead of directly arduino-cli allows to handle aliases
    args=("${words[@]:1}")
    requestComp="${words[0]} __completeNoDesc ${args[*]}"

    lastParam=${words[$((${#words[@]}-1))]}
    lastChar=${lastParam:$((${#lastParam}-1)):1}
    __arduino-cli_debug "lastParam ${lastParam}, lastChar ${lastChar}"

    if [ -z "${cur}" ] && [ "${lastChar}" != "=" ]; then
        # If the last parameter is complete (there is a space following it)
        # We add an extra empty parameter so we can indicate this to the go method.
        __arduino-cli_debug "Adding extra empty parameter"
        requestComp="${requestComp} ''"
    fi

    # When completing a flag with an = (e.g., arduino-cli -n=<TAB>)
    # bash focuses on the part after the =, so we need to remove
    # the flag part from $cur
    if [[ "${cur}" == -*=* ]]; then
        cur="${cur#*=}"
    fi

    __arduino-cli_debug "Calling ${requestComp}"
    # Use eval to handle any environment variables and such
    out=$(eval "${requestComp}" 2>/dev/null)

    # Extract the directive integer at the very end of the output following a colon (:)
    directive=${out##*:}
    # Remove the directive
    out=${out%:*}
    if [ "${directive}" = "${out}" ]; then
        # There is not directive specified
        directive=0
    fi
    __arduino-cli_debug "The completion directive is: ${directive}"
    __arduino-cli_debug "The completions are: ${out[*]}"
}

__arduino-cli_process_completion_results() {
    local shellCompDirectiveError=1
    local shellCompDirectiveNoSpace=2
    local shellCompDirectiveNoFileComp=4
    local shellCompDirectiveFilterFileExt=8
    local shellCompDirectiveFilterDirs=16

    if [ $((directive & shellCompDirectiveError)) -ne 0 ]; then
        # Error code.  No completion.
        __arduino-cli_debug "Received error from custom completion go code"
        return
    else
        if [ $((directive & shellCompDirectiveNoSpace)) -ne 0 ]; then
            if [[ $(type -t compopt) = "builtin" ]]; then
                __arduino-cli_debug "Activating no space"
                compopt -o nospace
            else
                __arduino-cli_debug "No space directive not supported in this version of bash"
            fi
        fi
        if [ $((directive & shellCompDirectiveNoFileComp)) -ne 0 ]; then
            if [[ $(type -t compopt) = "builtin" ]]; then
                __arduino-cli_debug "Activating no file completion"
                compopt +o default
            else
                __arduino-cli_debug "No file completion directive not supported in this version of bash"
            fi
        fi
    fi

    if [ $((directive & shellCompDirectiveFilterFileExt)) -ne 0 ]; then
        # File extension filtering
        local fullFilter filter filteringCmd

        # Do not use quotes around the $out variable or else newline
        # characters will be kept.
        for filter in ${out[*]}; do
            fullFilter+="$filter|"
        done

        filteringCmd="_filedir $fullFilter"
        __arduino-cli_debug "File filtering command: $filteringCmd"
        $filteringCmd
    elif [ $((directive & shellCompDirectiveFilterDirs)) -ne 0 ]; then
        # File completion for directories only

        # Use printf to strip any trailing newline
        local subdir
        subdir=$(printf "%s" "${out[0]}")
        if [ -n "$subdir" ]; then
            __arduino-cli_debug "Listing directories in $subdir"
            pushd "$subdir" >/dev/null 2>&1 && _filedir -d && popd >/dev/null 2>&1 || return
        else
            __arduino-cli_debug "Listing directories in ."
            _filedir -d
        fi
    else
        __arduino-cli_handle_standard_completion_case
    fi

    __arduino-cli_handle_special_char "$cur" :
    __arduino-cli_handle_special_char "$cur" =
}

__arduino-cli_handle_standard_completion_case() {
    local tab comp
    tab=$(printf '\t')

    local longest=0
    # Look for the longest completion so that we can format things nicely
    while IFS='' read -r comp; do
        # Strip any description before checking the length
        comp=${comp%%$tab*}
        # Only consider the completions that match
        comp=$(compgen -W "$comp" -- "$cur")
        if ((${#comp}>longest)); then
            longest=${#comp}
        fi
    done < <(printf "%s\n" "${out[@]}")

    local completions=()
    while IFS='' read -r comp; do
        if [ -z "$comp" ]; then
            continue
        fi

        __arduino-cli_debug "Original comp: $comp"
        comp="$(__arduino-cli_format_comp_descriptions "$comp" "$longest")"
        __arduino-cli_debug "Final comp: $comp"
        completions+=("$comp")
    done < <(printf "%s\n" "${out[@]}")

    while IFS='' read -r comp; do
        COMPREPLY+=("$comp")
    done < <(compgen -W "${completions[*]}" -- "$cur")

    # If there is a single completion left, remove the description text
    if [ ${#COMPREPLY[*]} -eq 1 ]; then
        __arduino-cli_debug "COMPREPLY[0]: ${COMPREPLY[0]}"
        comp="${COMPREPLY[0]%% *}"
        __arduino-cli_debug "Removed description from single completion, which is now: ${comp}"
        COMPREPLY=()
        COMPREPLY+=("$comp")
    fi
}

__arduino-cli_handle_special_char()
{
    local comp="$1"
    local char=$2
    if [[ "$comp" == *${char}* && "$COMP_WORDBREAKS" == *${char}* ]]; then
        local word=${comp%"${comp##*${char}}"}
        local idx=${#COMPREPLY[*]}
        while [[ $((--idx)) -ge 0 ]]; do
            COMPREPLY[$idx]=${COMPREPLY[$idx]#"$word"}
        done
    fi
}

__arduino-cli_format_comp_descriptions()
{
    local tab
    tab=$(printf '\t')
    local comp="$1"
    local longest=$2

    # Properly format the description string which follows a tab character if there is one
    if [[ "$comp" == *$tab* ]]; then
        desc=${comp#*$tab}
        comp=${comp%%$tab*}

        # $COLUMNS stores the current shell width.
        # Remove an extra 4 because we add 2 spaces and 2 parentheses.
        maxdesclength=$(( COLUMNS - longest - 4 ))

        # Make sure we can fit a description of at least 8 characters
        # if we are to align the descriptions.
        if [[ $maxdesclength -gt 8 ]]; then
            # Add the proper number of spaces to align the descriptions
            for ((i = ${#comp} ; i < longest ; i++)); do
                comp+=" "
            done
        else
            # Don't pad the descriptions so we can fit more text after the completion
            maxdesclength=$(( COLUMNS - ${#comp} - 4 ))
        fi

        # If there is enough space for any description text,
        # truncate the descriptions that are too long for the shell width
        if [ $maxdesclength -gt 0 ]; then
            if [ ${#desc} -gt $maxdesclength ]; then
                desc=${desc:0:$(( maxdesclength - 1 ))}
                desc+="…"
            fi
            comp+="  ($desc)"
        fi
    fi

    # Must use printf to escape all special characters
    printf "%q" "${comp}"
}

__start_arduino-cli()
{
    local cur prev words cword split

    COMPREPLY=()

    # Call _init_completion from the bash-completion package
    # to prepare the arguments properly
    if declare -F _init_completion >/dev/null 2>&1; then
        _init_completion -n "=:" || return
    else
        __arduino-cli_init_completion -n "=:" || return
    fi

    __arduino-cli_debug
    __arduino-cli_debug "========= starting completion logic =========="
    __arduino-cli_debug "cur is ${cur}, words[*] is ${words[*]}, #words[@] is ${#words[@]}, cword is $cword"

    # The user could have moved the cursor backwards on the command-line.
    # We need to trigger completion from the $cword location, so we need
    # to truncate the command-line ($words) up to the $cword location.
    words=("${words[@]:0:$cword+1}")
    __arduino-cli_debug "Truncated words[*]: ${words[*]},"

    local out directive
    __arduino-cli_get_completion_results
    __arduino-cli_process_completion_results
}

if [[ $(type -t compopt) = "builtin" ]]; then
    complete -o default -F __start_arduino-cli arduino-cli
else
    complete -o default -o nospace -F __start_arduino-cli arduino-cli
fi

# ex: ts=4 sw=4 et filetype=sh

Answer 1

UPDATE2：

在我发布这篇文章之后，我查看了你的链接，在看到了被接受的答案here之后，我想我只是老了，忘记了我只是从那个链接复制了这段代码，而不是我写的。即使在这里使用的示例也是相同的，但是进一步研究代码时，我似乎确实编写了这个代码，并使用了不同的方法，也许这将帮助您了解正在发生的事情。正如我在下面的UPDATE1部分中提到的:您需要调优COMP变量，然后调用原始函数

原件：

几年前我写了一个“别名包装”脚本。其思想是使用原始bash完成与别名，甚至与参数。例如：

    alias apti='apt-get install'
    source alias-completion-wrapper _apt_get apti apt-get install
    #here _apt_get is the original completion function

现在您可以使用选项卡在apti之后完成包名，就像在apt-get install之后一样

#alias-completion-wrapper
#Example: . alias-completion-wrapper _apt_get apti apt-get install

comp_function_name="$1"
ali="$2"
shift 2
x="$@"
function_name=`echo _$@ |tr ' ' _`
function="
    function $function_name {
       _completion_loader $1
       (( COMP_CWORD += $# - 1 ))
       COMP_WORDS=( $@ \"\${COMP_WORDS[@]:1}\")
       COMP_LINE=\"\${COMP_WORDS[@]}\"
       let COMP_POINT=\${COMP_POINT}-${#ali}+${#x}
       $comp_function_name
       return 0
    }"
eval "$function"
complete -F $function_name $ali
unset function function_name ali x

老实说，我不记得它是如何工作的，我也没有评论脚本:)，但我认为您可以根据您的需要对其进行调优。

UPDATE1：

当我稍微研究了一下代码时，它的想法似乎是调优COMP变量，然后调用原始函数:)

UPDATE3：

我有一些时间，所以你需要的修改是：

此${COMP_WORDS[@]}包含当前命令行。${COMP_WORDS[@]:1}切断了第一个单词，这个词最初是别名/命令。由于您想要在参数之后使用它，所以您也必须切断参数。

COMP_WORDS=( $@ \"\${COMP_WORDS[@]:2}\")

我在另一种解决方案中看不到COMP_LINE和COMP_POINT，但我记得如果没有这些解决方案，它在某些情况下不能很好地工作。所以我想你需要：

COMP_LINE=\"\${COMP_WORDS[@]:1}\"

这里，${#ali}是命令的长度。您需要用命令的长度替换为参数。例:"xcmd prm“-> 8(也计算空格)

let COMP_POINT=\${COMP_POINT}-${#ali}+${#x}

不确定(( COMP_CWORD += $# - 1 ))是否删除-1或使用-2或保持原样:)

修改后，只需将eval更改为echo并删除complete -F行。和source脚本，如所述。这样，它将响应您可以插入到完成脚本中的函数。