发明了另一个版本的轮子……

这个函数(希望)是一个posix兼容的普通bourne shell替换GNU getopt。它支持短/长选项，可以接受强制/可选/无参数，并且指定选项的方式几乎与GNU getopt相同，因此转换是微不足道的。

当然，要放入脚本中，这仍然是相当大的代码块，但它大约是众所周知的getopt_long shell函数的一半行数，并且在您只想替换现有的GNU getopt使用的情况下可能更可取。

这是相当新的代码，所以是YMMV(如果因为某种原因它实际上与POSIX不兼容，请务必告诉我——可移植性是一开始的意图，但我没有一个有用的POSIX测试环境)。

代码和示例用法如下:

#!/bin/sh
# posix_getopt shell function
# Author: Phil S.
# Version: 1.0
# Created: 2016-07-05
# URL: http://stackoverflow.com/a/37087374/324105

# POSIX-compatible argument quoting and parameter save/restore
# http://www.etalabs.net/sh_tricks.html
# Usage:
# parameters=$(save "$@") # save the original parameters.
# eval "set -- ${parameters}" # restore the saved parameters.
save () {
    local param
    for param; do
        printf %s\\n "$param" \
            | sed "s/'/'\\\\''/g;1s/^/'/;\$s/\$/' \\\\/"
    done
    printf %s\\n " "
}

# Exit with status $1 after displaying error message $2.
exiterr () {
    printf %s\\n "$2" >&2
    exit $1
}

# POSIX-compatible command line option parsing.
# This function supports long options and optional arguments, and is
# a (largely-compatible) drop-in replacement for GNU getopt.
#
# Instead of:
# opts=$(getopt -o "$shortopts" -l "$longopts" -- "$@")
# eval set -- ${opts}
#
# We instead use:
# opts=$(posix_getopt "$shortopts" "$longopts" "$@")
# eval "set -- ${opts}"
posix_getopt () { # args: "$shortopts" "$longopts" "$@"
    local shortopts longopts \
          arg argtype getopt nonopt opt optchar optword suffix

    shortopts="$1"
    longopts="$2"
    shift 2

    getopt=
    nonopt=
    while [ $# -gt 0 ]; do
        opt=
        arg=
        argtype=
        case "$1" in
            # '--' means don't parse the remaining options
            ( -- ) {
                getopt="${getopt}$(save "$@")"
                shift $#
                break
            };;
            # process short option
            ( -[!-]* ) {         # -x[foo]
                suffix=${1#-?}   # foo
                opt=${1%$suffix} # -x
                optchar=${opt#-} # x
                case "${shortopts}" in
                    ( *${optchar}::* ) { # optional argument
                        argtype=optional
                        arg="${suffix}"
                        shift
                    };;
                    ( *${optchar}:* ) { # required argument
                        argtype=required
                        if [ -n "${suffix}" ]; then
                            arg="${suffix}"
                            shift
                        else
                            case "$2" in
                                ( -* ) exiterr 1 "$1 requires an argument";;
                                ( ?* ) arg="$2"; shift 2;;
                                (  * ) exiterr 1 "$1 requires an argument";;
                            esac
                        fi
                    };;
                    ( *${optchar}* ) { # no argument
                        argtype=none
                        arg=
                        shift
                        # Handle multiple no-argument parameters combined as
                        # -xyz instead of -x -y -z. If we have just shifted
                        # parameter -xyz, we now replace it with -yz (which
                        # will be processed in the next iteration).
                        if [ -n "${suffix}" ]; then
                            eval "set -- $(save "-${suffix}")$(save "$@")"
                        fi
                    };;
                    ( * ) exiterr 1 "Unknown option $1";;
                esac
            };;
            # process long option
            ( --?* ) {            # --xarg[=foo]
                suffix=${1#*=}    # foo (unless there was no =)
                if [ "${suffix}" = "$1" ]; then
                    suffix=
                fi
                opt=${1%=$suffix} # --xarg
                optword=${opt#--} # xarg
                case ",${longopts}," in
                    ( *,${optword}::,* ) { # optional argument
                        argtype=optional
                        arg="${suffix}"
                        shift
                    };;
                    ( *,${optword}:,* ) { # required argument
                        argtype=required
                        if [ -n "${suffix}" ]; then
                            arg="${suffix}"
                            shift
                        else
                            case "$2" in
                                ( -* ) exiterr 1 \
                                       "--${optword} requires an argument";;
                                ( ?* ) arg="$2"; shift 2;;
                                (  * ) exiterr 1 \
                                       "--${optword} requires an argument";;
                            esac
                        fi
                    };;
                    ( *,${optword},* ) { # no argument
                        if [ -n "${suffix}" ]; then
                            exiterr 1 "--${optword} does not take an argument"
                        fi
                        argtype=none
                        arg=
                        shift
                    };;
                    ( * ) exiterr 1 "Unknown option $1";;
                esac
            };;
            # any other parameters starting with -
            ( -* ) exiterr 1 "Unknown option $1";;
            # remember non-option parameters
            ( * ) nonopt="${nonopt}$(save "$1")"; shift;;
        esac

        if [ -n "${opt}" ]; then
            getopt="${getopt}$(save "$opt")"
            case "${argtype}" in
                ( optional|required ) {
                    getopt="${getopt}$(save "$arg")"
                };;
            esac
        fi
    done

    # Generate function output, suitable for:
    # eval "set -- $(posix_getopt ...)"
    printf %s "${getopt}"
    if [ -n "${nonopt}" ]; then
        printf %s "$(save "--")${nonopt}"
    fi
}

使用示例:

# Process command line options
shortopts="hvd:c::s::L:D"
longopts="help,version,directory:,client::,server::,load:,delete"
#opts=$(getopt -o "$shortopts" -l "$longopts" -n "$(basename $0)" -- "$@")
opts=$(posix_getopt "$shortopts" "$longopts" "$@")
if [ $? -eq 0 ]; then
    #eval set -- ${opts}
    eval "set -- ${opts}"
    while [ $# -gt 0 ]; do
        case "$1" in
            ( --                ) shift; break;;
            ( -h|--help         ) help=1; shift; break;;
            ( -v|--version      ) version_help=1; shift; break;;
            ( -d|--directory    ) dir=$2; shift 2;;
            ( -c|--client       ) useclient=1; client=$2; shift 2;;
            ( -s|--server       ) startserver=1; server_name=$2; shift 2;;
            ( -L|--load         ) load=$2; shift 2;;
            ( -D|--delete       ) delete=1; shift;;
        esac
    done
else
    shorthelp=1 # getopt returned (and reported) an error.
fi

我是这样解决的:

# A string with command options
options=$@

# An array with all the arguments
arguments=($options)

# Loop index
index=0

for argument in $options
  do
    # Incrementing index
    index=`expr $index + 1`

    # The conditions
    case $argument in
      -a) echo "key $argument value ${arguments[index]}" ;;
      -abc) echo "key $argument value ${arguments[index]}" ;;
    esac
  done

exit;

我是不是太笨了?Getopt和getopts太让人困惑了。

为了保持跨平台兼容性，避免依赖外部可执行文件，我从另一种语言移植了一些代码。

我发现它很容易使用，这里有一个例子:

ArgParser::addArg "[h]elp"    false    "This list"
ArgParser::addArg "[q]uiet"   false    "Supress output"
ArgParser::addArg "[s]leep"   1        "Seconds to sleep"
ArgParser::addArg "v"         1        "Verbose mode"

ArgParser::parse "$@"

ArgParser::isset help && ArgParser::showArgs

ArgParser::isset "quiet" \
   && echo "Quiet!" \
   || echo "Noisy!"

local __sleep
ArgParser::tryAndGetArg sleep into __sleep \
   && echo "Sleep for $__sleep seconds" \
   || echo "No value passed for sleep"

# This way is often more convienient, but is a little slower
echo "Sleep set to: $( ArgParser::getArg sleep )"

所需的BASH有点长，但我希望避免依赖BASH 4的关联数组。你也可以直接从http://nt4.com/bash/argparser.inc.sh下载

#!/usr/bin/env bash

# Updates to this script may be found at
# http://nt4.com/bash/argparser.inc.sh

# Example of runtime usage:
# mnc.sh --nc -q Caprica.S0*mkv *.avi *.mp3 --more-options here --host centos8.host.com

# Example of use in script (see bottom)
# Just include this file in yours, or use
# source argparser.inc.sh

unset EXPLODED
declare -a EXPLODED
function explode 
{
    local c=$# 
    (( c < 2 )) && 
    {
        echo function "$0" is missing parameters 
        return 1
    }

    local delimiter="$1"
    local string="$2"
    local limit=${3-99}

    local tmp_delim=$'\x07'
    local delin=${string//$delimiter/$tmp_delim}
    local oldifs="$IFS"

    IFS="$tmp_delim"
    EXPLODED=($delin)
    IFS="$oldifs"
}


# See: http://fvue.nl/wiki/Bash:_Passing_variables_by_reference
# Usage: local "$1" && upvar $1 "value(s)"
upvar() {
    if unset -v "$1"; then           # Unset & validate varname
        if (( $# == 2 )); then
            eval $1=\"\$2\"          # Return single value
        else
            eval $1=\(\"\${@:2}\"\)  # Return array
        fi
    fi
}

function decho
{
    :
}

function ArgParser::check
{
    __args=${#__argparser__arglist[@]}
    for (( i=0; i<__args; i++ ))
    do
        matched=0
        explode "|" "${__argparser__arglist[$i]}"
        if [ "${#1}" -eq 1 ]
        then
            if [ "${1}" == "${EXPLODED[0]}" ]
            then
                decho "Matched $1 with ${EXPLODED[0]}"
                matched=1

                break
            fi
        else
            if [ "${1}" == "${EXPLODED[1]}" ]
            then
                decho "Matched $1 with ${EXPLODED[1]}"
                matched=1

                break
            fi
        fi
    done
    (( matched == 0 )) && return 2
    # decho "Key $key has default argument of ${EXPLODED[3]}"
    if [ "${EXPLODED[3]}" == "false" ]
    then
        return 0
    else
        return 1
    fi
}

function ArgParser::set
{
    key=$3
    value="${1:-true}"
    declare -g __argpassed__$key="$value"
}

function ArgParser::parse
{

    unset __argparser__argv
    __argparser__argv=()
    # echo parsing: "$@"

    while [ -n "$1" ]
    do
        # echo "Processing $1"
        if [ "${1:0:2}" == '--' ]
        then
            key=${1:2}
            value=$2
        elif [ "${1:0:1}" == '-' ]
        then
            key=${1:1}               # Strip off leading -
            value=$2
        else
            decho "Not argument or option: '$1'" >& 2
            __argparser__argv+=( "$1" )
            shift
            continue
        fi
        # parameter=${tmp%%=*}     # Extract name.
        # value=${tmp##*=}         # Extract value.
        decho "Key: '$key', value: '$value'"
        # eval $parameter=$value
        ArgParser::check $key
        el=$?
        # echo "Check returned $el for $key"
        [ $el -eq  2 ] && decho "No match for option '$1'" >&2 # && __argparser__argv+=( "$1" )
        [ $el -eq  0 ] && decho "Matched option '${EXPLODED[2]}' with no arguments"        >&2 && ArgParser::set true "${EXPLODED[@]}"
        [ $el -eq  1 ] && decho "Matched option '${EXPLODED[2]}' with an argument of '$2'"   >&2 && ArgParser::set "$2" "${EXPLODED[@]}" && shift
        shift
    done
}

function ArgParser::isset
{
    declare -p "__argpassed__$1" > /dev/null 2>&1 && return 0
    return 1
}

function ArgParser::getArg
{
    # This one would be a bit silly, since we can only return non-integer arguments ineffeciently
    varname="__argpassed__$1"
    echo "${!varname}"
}

##
# usage: tryAndGetArg <argname> into <varname>
# returns: 0 on success, 1 on failure
function ArgParser::tryAndGetArg
{
    local __varname="__argpassed__$1"
    local __value="${!__varname}"
    test -z "$__value" && return 1
    local "$3" && upvar $3 "$__value"
    return 0
}

function ArgParser::__construct
{
    unset __argparser__arglist
    # declare -a __argparser__arglist
}

##
# @brief add command line argument
# @param 1 short and/or long, eg: [s]hort
# @param 2 default value
# @param 3 description
##
function ArgParser::addArg
{
    # check for short arg within long arg
    if [[ "$1" =~ \[(.)\] ]]
    then
        short=${BASH_REMATCH[1]}
        long=${1/\[$short\]/$short}
    else
        long=$1
    fi
    if [ "${#long}" -eq 1 ]
    then
        short=$long
        long=''
    fi
    decho short: "$short"
    decho long: "$long"
    __argparser__arglist+=("$short|$long|$1|$2|$3")
}

## 
# @brief show available command line arguments
##
function ArgParser::showArgs
{
    # declare -p | grep argparser
    printf "Usage: %s [OPTION...]\n\n" "$( basename "${BASH_SOURCE[0]}" )"
    printf "Defaults for the options are specified in brackets.\n\n";

    __args=${#__argparser__arglist[@]}
    for (( i=0; i<__args; i++ ))
    do
        local shortname=
        local fullname=
        local default=
        local description=
        local comma=

        explode "|" "${__argparser__arglist[$i]}"

        shortname="${EXPLODED[0]:+-${EXPLODED[0]}}" # String Substitution Guide: 
        fullname="${EXPLODED[1]:+--${EXPLODED[1]}}" # http://tldp.org/LDP/abs/html/parameter-substitution.html
        test -n "$shortname" \
            && test -n "$fullname" \
            && comma=","

        default="${EXPLODED[3]}"
        case $default in
            false )
                default=
                ;;
            "" )
                default=
                ;;
            * )
                default="[$default]"
        esac

        description="${EXPLODED[4]}"

        printf "  %2s%1s %-19s %s %s\n" "$shortname" "$comma" "$fullname" "$description" "$default"
    done
}

function ArgParser::test
{
    # Arguments with a default of 'false' do not take paramaters (note: default
    # values are not applied in this release)

    ArgParser::addArg "[h]elp"      false       "This list"
    ArgParser::addArg "[q]uiet" false       "Supress output"
    ArgParser::addArg "[s]leep" 1           "Seconds to sleep"
    ArgParser::addArg "v"           1           "Verbose mode"

    ArgParser::parse "$@"

    ArgParser::isset help && ArgParser::showArgs

    ArgParser::isset "quiet" \
        && echo "Quiet!" \
        || echo "Noisy!"

    local __sleep
    ArgParser::tryAndGetArg sleep into __sleep \
        && echo "Sleep for $__sleep seconds" \
        || echo "No value passed for sleep"

    # This way is often more convienient, but is a little slower
    echo "Sleep set to: $( ArgParser::getArg sleep )"

    echo "Remaining command line: ${__argparser__argv[@]}"

}

if [ "$( basename "$0" )" == "argparser.inc.sh" ]
then
    ArgParser::test "$@"
fi

内置的getopts命令仍然仅限于单字符选项。

现在有(或者曾经有)一个外部程序getopt，它可以重新组织一组选项，使其更容易解析。你也可以调整这种设计来处理长选项。使用示例:

aflag=no
bflag=no
flist=""
set -- $(getopt abf: "$@")
while [ $# -gt 0 ]
do
    case "$1" in
    (-a) aflag=yes;;
    (-b) bflag=yes;;
    (-f) flist="$flist $2"; shift;;
    (--) shift; break;;
    (-*) echo "$0: error - unrecognized option $1" 1>&2; exit 1;;
    (*)  break;;
    esac
    shift
done

# Process remaining non-option arguments
...

您可以对getoptlong命令使用类似的方案。

请注意，外部getopt程序的基本弱点是难以处理其中包含空格的参数，以及难以准确地保留这些空格。这就是内置getopts优越的原因，尽管它只能处理单字母选项。

长选项可以被内置的标准getopts作为- " option "的"参数"解析。

这是可移植的本地POSIX shell -不需要外部程序或bashisms。

本指南将长选项作为-选项的参数实现，因此——alpha被getopts视为参数alpha为-，而——bravo=foo被参数bravo=foo视为-。true实参通过shell参数展开获取，更新$OPT和$OPTARG。

在本例中，-b和-c(以及它们的长形式——bravo和——charlie)具有强制实参。长选项的参数出现在等号之后，例如——bravo=foo(长选项的空格分隔符很难实现，参见下文)。

因为它使用了内置的getopts，所以这个解决方案支持像cmd——bravo=foo -ac FILE这样的用法(它组合了选项-a和-c，并将长选项与标准选项交织在一起)，而这里的大多数其他答案要么很难做到，要么无法做到这一点。

die() { echo "$*" >&2; exit 2; }  # complain to STDERR and exit with error
needs_arg() { if [ -z "$OPTARG" ]; then die "No arg for --$OPT option"; fi; }

while getopts ab:c:-: OPT; do
  # support long options: https://stackoverflow.com/a/28466267/519360
  if [ "$OPT" = "-" ]; then   # long option: reformulate OPT and OPTARG
    OPT="${OPTARG%%=*}"       # extract long option name
    OPTARG="${OPTARG#$OPT}"   # extract long option argument (may be empty)
    OPTARG="${OPTARG#=}"      # if long option argument, remove assigning `=`
  fi
  case "$OPT" in
    a | alpha )    alpha=true ;;
    b | bravo )    needs_arg; bravo="$OPTARG" ;;
    c | charlie )  needs_arg; charlie="$OPTARG" ;;
    ??* )          die "Illegal option --$OPT" ;;  # bad long option
    ? )            exit 2 ;;  # bad short option (error reported via getopts)
  esac
done
shift $((OPTIND-1)) # remove parsed options and args from $@ list

When the option is a dash (-), it is a long option. getopts will have parsed the actual long option into $OPTARG, e.g. --bravo=foo originally sets OPT='-' and OPTARG='bravo=foo'. The if stanza sets $OPT to the contents of $OPTARG before the first equals sign (bravo in our example) and then removes that from the beginning of $OPTARG (yielding =foo in this step, or an empty string if there is no =). Finally, we strip the argument's leading =. At this point, $OPT is either a short option (one character) or a long option (2+ characters).

The case then matches either short or long options (the pipe, |, indicates that "or" operation. A long-only option like delta ) delta=true ;; doesn't need a pipe). For short options, getopts automatically complains about options and missing arguments, so we have to replicate those manually using the needs_arg function, which fatally exits when $OPTARG is empty. The ??* condition will match any remaining long option (? matches a single character and * matches zero or more, so ??* matches 2+ characters), allowing us to issue the "Illegal option" error before exiting.

与正常的gnu风格的长选项一样，提供——将停止解析，因此- -- --bravo=4将把$alpha设置为true，但$bravo将保持不变，$1将-bravo=4。我不能说我建议用前导破折号来命名文件，但这是表示它们不是选项的方法。

小错误:如果有人给出了一个无效的单字符长选项(它也不是一个短选项)，这将退出一个错误，但没有消息(这个实现假设它是一个短选项)。您可以在case之前的条件中使用一个额外的变量来跟踪它，然后在最后的case条件中测试它，但我认为这是一个太麻烦的角落情况。

大写变量名:一般情况下，建议保留全大写变量供系统使用。我将$OPT保留为全大写，以与$OPTARG保持一致，但这确实打破了这种约定。我认为这很合适，因为这是系统应该做的事情，它应该是安全的;我还没有听说过任何使用这个变量名的标准。

要抱怨长选项的非预期实参:用翻转测试模拟needs_argg来抱怨一个非预期实参:

no_arg() { if [ -n "$OPTARG" ]; then die "No arg allowed for --$OPT option"; fi; }

要接受带空格分隔参数的长选项:您可以用eval "ARG_B=\"\$$OPTIND\""(或使用bash的间接展开，ARG_B="${!OPTIND}")拉入下一个参数，然后增加$OPTIND，正如这个答案的旧版本所指出的那样，但它不可靠;getopts可以过早地终止，假设参数超出了它的作用域，并且一些实现不太适合手动操作$OPTIND。

hm.

对纯bash选项不太满意。为什么不使用perl来得到你想要的。直接解析$*数组，并自动命名您的选项。

简单的帮助脚本:

#!/usr/bin/perl
use Getopt::Long;

my $optstring = shift;

my @opts = split(m#,#, $optstring);

my %opt;
GetOptions(\%opt, @opts);

print "set -- " . join(' ', map("'$_'", @ARGV)) . ";";
my $xx;

my $key;
foreach $key (keys(%opt))
{
    print "export $key='$opt{$key}'; ";
}

然后你可以在你的脚本中使用一行，例如:

#!/bin/bash

eval `getopts.pl reuse:s,long_opt:s,hello $*`;

echo "HELLO: $hello"
echo "LONG_OPT: $long_opt"
echo "REUSE: $reuse"

echo $*

/tmp/script.sh hello——reuse me——long_opt whatever_you_want_except_spaces——hello 1 2 3

你好:1 LONG_OPT: whatever_you_want_except空格 重用:我

1, 2, 3

这里唯一需要注意的是空格不适用。但它避免了bash相当复杂的循环语法，适用于长参数，自动将它们命名为变量并自动调整$*的大小，因此99%的时间都是有效的。