改进的解决方案:

# translate long options to short
# Note: This enable long options but disable "--?*" in $OPTARG, or disable long options after  "--" in option fields.
for ((i=1;$#;i++)) ; do
    case "$1" in
        --)
            # [ ${args[$((i-1))]} == ... ] || EndOpt=1 ;;& # DIRTY: we still can handle some execptions...
            EndOpt=1 ;;&
        --version) ((EndOpt)) && args[$i]="$1"  || args[$i]="-V";;
        # default case : short option use the first char of the long option:
        --?*) ((EndOpt)) && args[$i]="$1"  || args[$i]="-${1:2:1}";;
        # pass through anything else:
        *) args[$i]="$1" ;;
    esac
    shift
done
# reset the translated args
set -- "${args[@]}"

function usage {
echo "Usage: $0 [options] files" >&2
    exit $1
}

# now we can process with getopt
while getopts ":hvVc:" opt; do
    case $opt in
        h)  usage ;;
        v)  VERBOSE=true ;;
        V)  echo $Version ; exit ;;
        c)  source $OPTARG ;;
        \?) echo "unrecognized option: -$opt" ; usage -1 ;;
        :)
        echo "option -$OPTARG requires an argument"
        usage -1
        ;;
    esac
done

shift $((OPTIND-1))
[[ "$1" == "--" ]] && shift

如果你不想要getopt依赖，你可以这样做:

while test $# -gt 0
do
  case $1 in

  # Normal option processing
    -h | --help)
      # usage and help
      ;;
    -v | --version)
      # version info
      ;;
  # ...

  # Special cases
    --)
      break
      ;;
    --*)
      # error unknown (long) option $1
      ;;
    -?)
      # error unknown (short) option $1
      ;;

  # FUN STUFF HERE:
  # Split apart combined short options
    -*)
      split=$1
      shift
      set -- $(echo "$split" | cut -c 2- | sed 's/./-& /g') "$@"
      continue
      ;;

  # Done with options
    *)
      break
      ;;
  esac

  # for testing purposes:
  echo "$1"

  shift
done

当然，这样你就不能使用长样式选项。如果你想添加缩短的版本(例如——verbos而不是——verbose)，那么你需要手动添加这些。

但是如果您希望获得getopts功能和长选项，这是一种简单的方法。

我也把这个片段作为一个主旨。

如果这就是您想要调用脚本的方式

myscript.sh --input1 "ABC" --input2 "PQR" --input2 "XYZ"

然后，您可以使用getopt和——longoptions来实现这个最简单的方法

试试这个，希望对你有用

# Read command line options
ARGUMENT_LIST=(
    "input1"
    "input2"
    "input3"
)



# read arguments
opts=$(getopt \
    --longoptions "$(printf "%s:," "${ARGUMENT_LIST[@]}")" \
    --name "$(basename "$0")" \
    --options "" \
    -- "$@"
)


echo $opts

eval set --$opts

while true; do
    case "$1" in
    --input1)  
        shift
        empId=$1
        ;;
    --input2)  
        shift
        fromDate=$1
        ;;
    --input3)  
        shift
        toDate=$1
        ;;
      --)
        shift
        break
        ;;
    esac
    shift
done

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

可以考虑以下三种实现方式:

Bash内置的getopts。这不支持带有双破折号前缀的长选项名。它只支持单字符选项。 BSD UNIX实现的独立getopt命令(这是MacOS使用的)。这也不支持长选项。 独立getopt的GNU实现。GNU getopt(3)(由Linux上的命令行getopt(1)使用)支持解析长选项。

其他一些答案给出了使用bash内置getopts模拟长选项的解决方案。该解决方案实际上生成了一个字符为“-”的短选项。所以你得到“——”作为标志。然后，后面的所有内容都变成OPTARG，并使用嵌套的case测试OPTARG。

这很聪明，但也需要注意:

getopts不能强制执行opt规范。如果用户提供了无效的选项，它不能返回错误。在解析OPTARG时，您必须自己进行错误检查。 OPTARG用于长选项名称，当长选项本身有参数时，这会使使用复杂化。你最终不得不自己编写代码作为一个额外的案例。

因此，虽然可以编写更多的代码来解决长选项支持不足的问题，但工作量要大得多，并且在一定程度上违背了使用getopt解析器来简化代码的目的。

我想要一个没有外部依赖关系、有严格bash支持(-u)的东西，而且我需要它能在较旧的bash版本上工作。这个函数处理各种类型的参数:

短bool (-h) 短选项(-i "image.jpg") 长boos(——救命) = options(——file="filename.ext") 空格选项(——file "filename.ext") 连接的bool (-hvm)

只需在脚本顶部插入以下内容:

# Check if a list of params contains a specific param
# usage: if _param_variant "h|?|help p|path f|file long-thing t|test-thing" "file" ; then ...
# the global variable $key is updated to the long notation (last entry in the pipe delineated list, if applicable)
_param_variant() {
  for param in $1 ; do
    local variants=${param//\|/ }
    for variant in $variants ; do
      if [[ "$variant" = "$2" ]] ; then
        # Update the key to match the long version
        local arr=(${param//\|/ })
        let last=${#arr[@]}-1
        key="${arr[$last]}"
        return 0
      fi
    done
  done
  return 1
}

# Get input parameters in short or long notation, with no dependencies beyond bash
# usage:
#     # First, set your defaults
#     param_help=false
#     param_path="."
#     param_file=false
#     param_image=false
#     param_image_lossy=true
#     # Define allowed parameters
#     allowed_params="h|?|help p|path f|file i|image image-lossy"
#     # Get parameters from the arguments provided
#     _get_params $*
#
# Parameters will be converted into safe variable names like:
#     param_help,
#     param_path,
#     param_file,
#     param_image,
#     param_image_lossy
#
# Parameters without a value like "-h" or "--help" will be treated as
# boolean, and will be set as param_help=true
#
# Parameters can accept values in the various typical ways:
#     -i "path/goes/here"
#     --image "path/goes/here"
#     --image="path/goes/here"
#     --image=path/goes/here
# These would all result in effectively the same thing:
#     param_image="path/goes/here"
#
# Concatinated short parameters (boolean) are also supported
#     -vhm is the same as -v -h -m
_get_params(){

  local param_pair
  local key
  local value
  local shift_count

  while : ; do
    # Ensure we have a valid param. Allows this to work even in -u mode.
    if [[ $# == 0 || -z $1 ]] ; then
      break
    fi

    # Split the argument if it contains "="
    param_pair=(${1//=/ })
    # Remove preceeding dashes
    key="${param_pair[0]#--}"

    # Check for concatinated boolean short parameters.
    local nodash="${key#-}"
    local breakout=false
    if [[ "$nodash" != "$key" && ${#nodash} -gt 1 ]]; then
      # Extrapolate multiple boolean keys in single dash notation. ie. "-vmh" should translate to: "-v -m -h"
      local short_param_count=${#nodash}
      let new_arg_count=$#+$short_param_count-1
      local new_args=""
      # $str_pos is the current position in the short param string $nodash
      for (( str_pos=0; str_pos<new_arg_count; str_pos++ )); do
        # The first character becomes the current key
        if [ $str_pos -eq 0 ] ; then
          key="${nodash:$str_pos:1}"
          breakout=true
        fi
        # $arg_pos is the current position in the constructed arguments list
        let arg_pos=$str_pos+1
        if [ $arg_pos -gt $short_param_count ] ; then
          # handle other arguments
          let orignal_arg_number=$arg_pos-$short_param_count+1
          local new_arg="${!orignal_arg_number}"
        else
          # break out our one argument into new ones
          local new_arg="-${nodash:$str_pos:1}"
        fi
        new_args="$new_args \"$new_arg\""
      done
      # remove the preceding space and set the new arguments
      eval set -- "${new_args# }"
    fi
    if ! $breakout ; then
      key="$nodash"
    fi

    # By default we expect to shift one argument at a time
    shift_count=1
    if [ "${#param_pair[@]}" -gt "1" ] ; then
      # This is a param with equals notation
      value="${param_pair[1]}"
    else
      # This is either a boolean param and there is no value,
      # or the value is the next command line argument
      # Assume the value is a boolean true, unless the next argument is found to be a value.
      value=true
      if [[ $# -gt 1 && -n "$2" ]]; then
        local nodash="${2#-}"
        if [ "$nodash" = "$2" ]; then
          # The next argument has NO preceding dash so it is a value
          value="$2"
          shift_count=2
        fi
      fi
    fi

    # Check that the param being passed is one of the allowed params
    if _param_variant "$allowed_params" "$key" ; then
      # --key-name will now become param_key_name
      eval param_${key//-/_}="$value"
    else
      printf 'WARNING: Unknown option (ignored): %s\n' "$1" >&2
    fi
    shift $shift_count
  done
}

像这样使用它:

# Assign defaults for parameters
param_help=false
param_path=$(pwd)
param_file=false
param_image=true
param_image_lossy=true
param_image_lossy_quality=85

# Define the params we will allow
allowed_params="h|?|help p|path f|file i|image image-lossy image-lossy-quality"

# Get the params from arguments provided
_get_params $*