Bash空格分隔（例如--option参数）

cat >/tmp/demo-space-separated.sh <<'EOF'
#!/bin/bash

POSITIONAL_ARGS=()

while [[ $# -gt 0 ]]; do
  case $1 in
    -e|--extension)
      EXTENSION="$2"
      shift # past argument
      shift # past value
      ;;
    -s|--searchpath)
      SEARCHPATH="$2"
      shift # past argument
      shift # past value
      ;;
    --default)
      DEFAULT=YES
      shift # past argument
      ;;
    -*|--*)
      echo "Unknown option $1"
      exit 1
      ;;
    *)
      POSITIONAL_ARGS+=("$1") # save positional arg
      shift # past argument
      ;;
  esac
done

set -- "${POSITIONAL_ARGS[@]}" # restore positional parameters

echo "FILE EXTENSION  = ${EXTENSION}"
echo "SEARCH PATH     = ${SEARCHPATH}"
echo "DEFAULT         = ${DEFAULT}"
echo "Number files in SEARCH PATH with EXTENSION:" $(ls -1 "${SEARCHPATH}"/*."${EXTENSION}" | wc -l)

if [[ -n $1 ]]; then
    echo "Last line of file specified as non-opt/last argument:"
    tail -1 "$1"
fi
EOF

chmod +x /tmp/demo-space-separated.sh

/tmp/demo-space-separated.sh -e conf -s /etc /etc/hosts

复制粘贴上面的块的输出

FILE EXTENSION  = conf
SEARCH PATH     = /etc
DEFAULT         =
Number files in SEARCH PATH with EXTENSION: 14
Last line of file specified as non-opt/last argument:
#93.184.216.34    example.com

用法

demo-space-separated.sh -e conf -s /etc /etc/hosts

---

Bash等于分隔符（例如，--option=argument）

cat >/tmp/demo-equals-separated.sh <<'EOF'
#!/bin/bash

for i in "$@"; do
  case $i in
    -e=*|--extension=*)
      EXTENSION="${i#*=}"
      shift # past argument=value
      ;;
    -s=*|--searchpath=*)
      SEARCHPATH="${i#*=}"
      shift # past argument=value
      ;;
    --default)
      DEFAULT=YES
      shift # past argument with no value
      ;;
    -*|--*)
      echo "Unknown option $i"
      exit 1
      ;;
    *)
      ;;
  esac
done

echo "FILE EXTENSION  = ${EXTENSION}"
echo "SEARCH PATH     = ${SEARCHPATH}"
echo "DEFAULT         = ${DEFAULT}"
echo "Number files in SEARCH PATH with EXTENSION:" $(ls -1 "${SEARCHPATH}"/*."${EXTENSION}" | wc -l)

if [[ -n $1 ]]; then
    echo "Last line of file specified as non-opt/last argument:"
    tail -1 $1
fi
EOF

chmod +x /tmp/demo-equals-separated.sh

/tmp/demo-equals-separated.sh -e=conf -s=/etc /etc/hosts

复制粘贴上面的块的输出

FILE EXTENSION  = conf
SEARCH PATH     = /etc
DEFAULT         =
Number files in SEARCH PATH with EXTENSION: 14
Last line of file specified as non-opt/last argument:
#93.184.216.34    example.com

用法

demo-equals-separated.sh -e=conf -s=/etc /etc/hosts

---

要更好地理解${i#*=}，请在本指南中搜索“Substring Removal”。它在功能上等同于调用一个不需要的子流程的‘sed’s/[^=]*=//'<<<“$i”`或调用两个不需要子流程的“echo”$i”|sed’s/[^=]*=//'`。

---

将bash与getopt[s]一起使用

getopt（1）限制（较旧、较新的getopt版本）：

无法处理空字符串的参数无法处理带有嵌入空格的参数

最近的getopt版本没有这些限制。有关更多信息，请参阅这些文档。

---

POSIX获取选项

此外，POSIX外壳和其他提供的getopts没有这些限制。我包含了一个简单的getopts示例。

cat >/tmp/demo-getopts.sh <<'EOF'
#!/bin/sh

# A POSIX variable
OPTIND=1         # Reset in case getopts has been used previously in the shell.

# Initialize our own variables:
output_file=""
verbose=0

while getopts "h?vf:" opt; do
  case "$opt" in
    h|\?)
      show_help
      exit 0
      ;;
    v)  verbose=1
      ;;
    f)  output_file=$OPTARG
      ;;
  esac
done

shift $((OPTIND-1))

[ "${1:-}" = "--" ] && shift

echo "verbose=$verbose, output_file='$output_file', Leftovers: $@"
EOF

chmod +x /tmp/demo-getopts.sh

/tmp/demo-getopts.sh -vf /etc/hosts foo bar

复制粘贴上面的块的输出

verbose=1, output_file='/etc/hosts', Leftovers: foo bar

用法

demo-getopts.sh -vf /etc/hosts foo bar

getopts的优点是：

它更便于携带，可以在其他外壳中使用，如dash。它可以以典型的Unix方式自动处理多个单一选项，如-vf文件名。

getopts的缺点是它只能处理短选项（-h，而不是-help），而无需额外代码。

有一个getopts教程，它解释了所有语法和变量的含义。在bash中，还有帮助getopts，这可能会提供信息。

混合位置和基于标志的参数

--param=arg（等于分隔符）

在位置参数之间自由混合标志：

./script.sh dumbo 127.0.0.1 --environment=production -q -d
./script.sh dumbo --environment=production 127.0.0.1 --quiet -d

可以用相当简洁的方法完成：

# process flags
pointer=1
while [[ $pointer -le $# ]]; do
   param=${!pointer}
   if [[ $param != "-"* ]]; then ((pointer++)) # not a parameter flag so advance pointer
   else
      case $param in
         # paramter-flags with arguments
         -e=*|--environment=*) environment="${param#*=}";;
                  --another=*) another="${param#*=}";;

         # binary flags
         -q|--quiet) quiet=true;;
                 -d) debug=true;;
      esac

      # splice out pointer frame from positional list
      [[ $pointer -gt 1 ]] \
         && set -- ${@:1:((pointer - 1))} ${@:((pointer + 1)):$#} \
         || set -- ${@:((pointer + 1)):$#};
   fi
done

# positional remain
node_name=$1
ip_address=$2

--参数arg（空格分隔）

通常情况下，不混合--flag=value和--flag值样式会更清晰。

./script.sh dumbo 127.0.0.1 --environment production -q -d

这读起来有点冒险，但仍然有效

./script.sh dumbo --environment production 127.0.0.1 --quiet -d

来源

# process flags
pointer=1
while [[ $pointer -le $# ]]; do
   if [[ ${!pointer} != "-"* ]]; then ((pointer++)) # not a parameter flag so advance pointer
   else
      param=${!pointer}
      ((pointer_plus = pointer + 1))
      slice_len=1

      case $param in
         # paramter-flags with arguments
         -e|--environment) environment=${!pointer_plus}; ((slice_len++));;
                --another) another=${!pointer_plus}; ((slice_len++));;

         # binary flags
         -q|--quiet) quiet=true;;
                 -d) debug=true;;
      esac

      # splice out pointer frame from positional list
      [[ $pointer -gt 1 ]] \
         && set -- ${@:1:((pointer - 1))} ${@:((pointer + $slice_len)):$#} \
         || set -- ${@:((pointer + $slice_len)):$#};
   fi
done

# positional remain
node_name=$1
ip_address=$2

来自digitalpeer.com，稍作修改：

用法myscript.sh-p=my_prefix-s=dirname-l=libname

#!/bin/bash
for i in "$@"
do
case $i in
    -p=*|--prefix=*)
    PREFIX="${i#*=}"

    ;;
    -s=*|--searchpath=*)
    SEARCHPATH="${i#*=}"
    ;;
    -l=*|--lib=*)
    DIR="${i#*=}"
    ;;
    --default)
    DEFAULT=YES
    ;;
    *)
            # unknown option
    ;;
esac
done
echo PREFIX = ${PREFIX}
echo SEARCH PATH = ${SEARCHPATH}
echo DIRS = ${DIR}
echo DEFAULT = ${DEFAULT}

要更好地理解${i#*=}，请在本指南中搜索“Substring Removal”。它在功能上等同于调用一个不需要的子流程的‘sed’s/[^=]*=//'<<<“$i”`或调用两个不需要子流程的“echo”$i”|sed’s/[^=]*=//'`。

此示例显示了如何使用getopt和eval以及HEREDOC和shift来处理短参数和长参数，以及是否具有以下所需值。此外，switch/case语句简洁易懂。

#!/usr/bin/env bash

# usage function
function usage()
{
   cat << HEREDOC

   Usage: $progname [--num NUM] [--time TIME_STR] [--verbose] [--dry-run]

   optional arguments:
     -h, --help           show this help message and exit
     -n, --num NUM        pass in a number
     -t, --time TIME_STR  pass in a time string
     -v, --verbose        increase the verbosity of the bash script
     --dry-run            do a dry run, dont change any files

HEREDOC
}  

# initialize variables
progname=$(basename $0)
verbose=0
dryrun=0
num_str=
time_str=

# use getopt and store the output into $OPTS
# note the use of -o for the short options, --long for the long name options
# and a : for any option that takes a parameter
OPTS=$(getopt -o "hn:t:v" --long "help,num:,time:,verbose,dry-run" -n "$progname" -- "$@")
if [ $? != 0 ] ; then echo "Error in command line arguments." >&2 ; usage; exit 1 ; fi
eval set -- "$OPTS"

while true; do
  # uncomment the next line to see how shift is working
  # echo "\$1:\"$1\" \$2:\"$2\""
  case "$1" in
    -h | --help ) usage; exit; ;;
    -n | --num ) num_str="$2"; shift 2 ;;
    -t | --time ) time_str="$2"; shift 2 ;;
    --dry-run ) dryrun=1; shift ;;
    -v | --verbose ) verbose=$((verbose + 1)); shift ;;
    -- ) shift; break ;;
    * ) break ;;
  esac
done

if (( $verbose > 0 )); then

   # print out all the parameters we read in
   cat <<EOM
   num=$num_str
   time=$time_str
   verbose=$verbose
   dryrun=$dryrun
EOM
fi

# The rest of your script below

以上脚本中最重要的几行是：

OPTS=$(getopt -o "hn:t:v" --long "help,num:,time:,verbose,dry-run" -n "$progname" -- "$@")
if [ $? != 0 ] ; then echo "Error in command line arguments." >&2 ; exit 1 ; fi
eval set -- "$OPTS"

while true; do
  case "$1" in
    -h | --help ) usage; exit; ;;
    -n | --num ) num_str="$2"; shift 2 ;;
    -t | --time ) time_str="$2"; shift 2 ;;
    --dry-run ) dryrun=1; shift ;;
    -v | --verbose ) verbose=$((verbose + 1)); shift ;;
    -- ) shift; break ;;
    * ) break ;;
  esac
done

简短，切中要害，可读，处理几乎所有的事情（IMHO）。

希望这对某人有所帮助。

我给你一个函数parse_params，它将从命令行解析参数。

这是一个纯Bash解决方案，没有额外的实用程序。不会污染全球范围。轻松地返回简单易用的变量，您可以在这些变量上构建进一步的逻辑。params前面的破折号数量无关紧要（--all等于-all等于all=all）

下面的脚本是复制粘贴工作演示。请参见show_use函数以了解如何使用parse_param。

限制：

不支持空格分隔的参数（-d 1）参数名称将丢失破折号，因此--any参数和-anyparam等效eval$（parse_params“$@”）必须在bash函数中使用（它在全局范围内不起作用）

---

#!/bin/bash

# Universal Bash parameter parsing
# Parse equal sign separated params into named local variables
# Standalone named parameter value will equal its param name (--force creates variable $force=="force")
# Parses multi-valued named params into an array (--path=path1 --path=path2 creates ${path[*]} array)
# Puts un-named params as-is into ${ARGV[*]} array
# Additionally puts all named params as-is into ${ARGN[*]} array
# Additionally puts all standalone "option" params as-is into ${ARGO[*]} array
# @author Oleksii Chekulaiev
# @version v1.4.1 (Jul-27-2018)
parse_params ()
{
    local existing_named
    local ARGV=() # un-named params
    local ARGN=() # named params
    local ARGO=() # options (--params)
    echo "local ARGV=(); local ARGN=(); local ARGO=();"
    while [[ "$1" != "" ]]; do
        # Escape asterisk to prevent bash asterisk expansion, and quotes to prevent string breakage
        _escaped=${1/\*/\'\"*\"\'}
        _escaped=${_escaped//\'/\\\'}
        _escaped=${_escaped//\"/\\\"}
        # If equals delimited named parameter
        nonspace="[^[:space:]]"
        if [[ "$1" =~ ^${nonspace}${nonspace}*=..* ]]; then
            # Add to named parameters array
            echo "ARGN+=('$_escaped');"
            # key is part before first =
            local _key=$(echo "$1" | cut -d = -f 1)
            # Just add as non-named when key is empty or contains space
            if [[ "$_key" == "" || "$_key" =~ " " ]]; then
                echo "ARGV+=('$_escaped');"
                shift
                continue
            fi
            # val is everything after key and = (protect from param==value error)
            local _val="${1/$_key=}"
            # remove dashes from key name
            _key=${_key//\-}
            # skip when key is empty
            # search for existing parameter name
            if (echo "$existing_named" | grep "\b$_key\b" >/dev/null); then
                # if name already exists then it's a multi-value named parameter
                # re-declare it as an array if needed
                if ! (declare -p _key 2> /dev/null | grep -q 'declare \-a'); then
                    echo "$_key=(\"\$$_key\");"
                fi
                # append new value
                echo "$_key+=('$_val');"
            else
                # single-value named parameter
                echo "local $_key='$_val';"
                existing_named=" $_key"
            fi
        # If standalone named parameter
        elif [[ "$1" =~ ^\-${nonspace}+ ]]; then
            # remove dashes
            local _key=${1//\-}
            # Just add as non-named when key is empty or contains space
            if [[ "$_key" == "" || "$_key" =~ " " ]]; then
                echo "ARGV+=('$_escaped');"
                shift
                continue
            fi
            # Add to options array
            echo "ARGO+=('$_escaped');"
            echo "local $_key=\"$_key\";"
        # non-named parameter
        else
            # Escape asterisk to prevent bash asterisk expansion
            _escaped=${1/\*/\'\"*\"\'}
            echo "ARGV+=('$_escaped');"
        fi
        shift
    done
}

#--------------------------- DEMO OF THE USAGE -------------------------------

show_use ()
{
    eval $(parse_params "$@")
    # --
    echo "${ARGV[0]}" # print first unnamed param
    echo "${ARGV[1]}" # print second unnamed param
    echo "${ARGN[0]}" # print first named param
    echo "${ARG0[0]}" # print first option param (--force)
    echo "$anyparam"  # print --anyparam value
    echo "$k"         # print k=5 value
    echo "${multivalue[0]}" # print first value of multi-value
    echo "${multivalue[1]}" # print second value of multi-value
    [[ "$force" == "force" ]] && echo "\$force is set so let the force be with you"
}

show_use "param 1" --anyparam="my value" param2 k=5 --force --multi-value=test1 --multi-value=test2

如果您正在制作可与其他实用程序互换的脚本，下面的灵活性可能很有用。

以下任一项：

command -x=myfilename.ext --another_switch 

Or:

command -x myfilename.ext --another_switch

代码如下：

STD_IN=0

prefix=""
key=""
value=""
for keyValue in "$@"
do
  case "${prefix}${keyValue}" in
    -i=*|--input_filename=*)  key="-i";     value="${keyValue#*=}";; 
    -ss=*|--seek_from=*)      key="-ss";    value="${keyValue#*=}";;
    -t=*|--play_seconds=*)    key="-t";     value="${keyValue#*=}";;
    -|--stdin)                key="-";      value=1;;
    *)                                      value=$keyValue;;
  esac
  case $key in
    -i) MOVIE=$(resolveMovie "${value}");  prefix=""; key="";;
    -ss) SEEK_FROM="${value}";          prefix=""; key="";;
    -t)  PLAY_SECONDS="${value}";           prefix=""; key="";;
    -)   STD_IN=${value};                   prefix=""; key="";; 
    *)   prefix="${keyValue}=";;
  esac
done