Bash 脚本命令处理程序替换长 if 链

Question

假设我有一堆 if 语句，其形式如下:

if(设置了某些标志变量/参数)然后 执行另一个命令或 bash 脚本

这维护起来有点麻烦，所以我想知道是否有其他方法可以做到这一点。而这个guide对于node.js，我想知道是否可以在bash中实现类似的东西

Answer 1

我想知道您是否正在寻找这样的东西:

#!/bin/bash

# initialize global options 
debug=false
verbose=0

main() {
    local OPTIND
    while getopts :hdv: opt; do
        case $opt in
            h) show_help; exit ;;
            d) debug=true ;;
            v) verbose=$OPTARG;;
            :) echo "error: missing argument for -$OPTARG"; exit 1;;
            ?) echo "error: unknown option -$OPTARG"; exit 1 ;;
        esac
    done
    shift $((OPTIND-1))
    if [[ -z $1 ]]; then
        echo "error: missing subcommand"
        show_help
        exit 1
    fi
    case $1 in
        bar|baz) 
            # invoke the command with the arguments
            "$@" ;;
        *) echo "error: unknown subcommand $1"; exit 1;;
    esac
}

show_help() {
    echo "usage: $(basename "$0") [global opts] subcommand [local opts and args]"
    echo "... more details..."
}

bar() {
    echo "you called $FUNCNAME with args $*"
}

baz() {
    echo "this is baz"
    local OPTIND
    while getopts :ab opt; do
        case $opt in
            a|b) echo "you selected option $opt";;
            ?) echo "unknown option -$OPTARG";;
        esac
    done
    if $debug; then echo "some debug message"; fi
    (( verbose > 0 )) && echo "some verbose message"
}

main "$@"