我希望使用shell脚本调用长形式和短形式的命令行选项。
我知道可以使用getopts，但是像在Perl中一样，我不能用shell做同样的事情。
关于如何做到这一点的任何想法，这样我就可以使用如下选项:
./shell.sh --copyfile abc.pl /tmp/
./shell.sh -c abc.pl /tmp/
在上面，这两个命令对我的shell意味着同样的事情，但使用getopts，我还不能实现这些?
当前回答
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
其他回答
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))
[[ "$1" == "--" ]] && shift
长选项可以被内置的标准getopts作为- " option "的"参数"解析。
这是可移植的本地POSIX shell -不需要外部程序或bashisms。
本指南将长选项作为-选项的参数实现，因此——alpha被getopts视为参数alpha为-，而——bravo=foo被参数bravo=foo视为-。true实参通过shell参数展开获取，更新$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$OPTIND。
发明了另一个版本的轮子……
这个函数(希望)是一个posix兼容的普通bourne shell替换GNU getopt。它支持短/长选项，可以接受强制/可选/无参数，并且指定选项的方式几乎与GNU getopt相同，因此转换是微不足道的。
当然，要放入脚本中，这仍然是相当大的代码块，但它大约是众所周知的getopt_long shell函数的一半行数，并且在您只想替换现有的GNU getopt使用的情况下可能更可取。
这是相当新的代码，所以是YMMV(如果因为某种原因它实际上与POSIX不兼容，请务必告诉我——可移植性是一开始的意图，但我没有一个有用的POSIX测试环境)。
代码和示例用法如下:
#!/bin/sh
# posix_getopt shell function
# Author: Phil S.
# Version: 1.0
# Created: 2016-07-05
# URL: http://stackoverflow.com/a/37087374/324105
# POSIX-compatible argument quoting and parameter save/restore
# http://www.etalabs.net/sh_tricks.html
# Usage:
# parameters=$(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=$2; shift 2;;
( -D|--delete ) delete=1; shift;;
esac
done
else
shorthelp=1 # getopt returned (and reported) an error.
fi
Bash内置的getopts函数可以通过在optspec中放入破折号和冒号来解析长选项:
#!/usr/bin/env bash
optspec=":hv-:"
while getopts "$optspec" optchar; do
case "${optchar}" in
-)
case "${OPTARG}" in
loglevel)
val="${!OPTIND}"; OPTIND=$(( $OPTIND + 1 ))
echo "Parsing option: '--${OPTARG}', value: '${val}'" >&2;
;;
loglevel=*)
val=${OPTARG#*=}
opt=${OPTARG%=$val}
echo "Parsing option: '--${opt}', value: '${val}'" >&2
;;
*)
if [ "$OPTERR" = 1 ] && [ "${optspec:0:1}" != ":" ]; then
echo "Unknown option --${OPTARG}" >&2
fi
;;
esac;;
h)
echo "usage: $0 [-v] [--loglevel[=]<value>]" >&2
exit 2
;;
v)
echo "Parsing option: '-${optchar}'" >&2
;;
*)
if [ "$OPTERR" != 1 ] || [ "${optspec:0:1}" = ":" ]; then
echo "Non-option argument: '-${OPTARG}'" >&2
fi
;;
esac
done
拷贝到当前工作目录中的可执行文件name=getopts_test.sh后，可以生成如下输出
$ ./getopts_test.sh
$ ./getopts_test.sh -f
Non-option argument: '-f'
$ ./getopts_test.sh -h
usage: code/getopts_test.sh [-v] [--loglevel[=]<value>]
$ ./getopts_test.sh --help
$ ./getopts_test.sh -v
Parsing option: '-v'
$ ./getopts_test.sh --very-bad
$ ./getopts_test.sh --loglevel
Parsing option: '--loglevel', value: ''
$ ./getopts_test.sh --loglevel 11
Parsing option: '--loglevel', value: '11'
$ ./getopts_test.sh --loglevel=11
Parsing option: '--loglevel', value: '11'
显然，getopts既不执行OPTERR检查，也不对长选项执行选项参数解析。上面的脚本片段展示了如何手动完成这一工作。基本原理也适用于Debian Almquist shell(“破折号”)。注意特殊情况:
getopts -- "-:" ## without the option terminator "-- " bash complains about "-:"
getopts "-:" ## this works in the Debian Almquist shell ("dash")
请注意，正如http://mywiki.wooledge.org/BashFAQ上的GreyCat指出的那样，这个技巧利用了shell的非标准行为，允许选项参数(即“-ffilename”中的文件名)连接到选项(如“-ffilename”)。POSIX标准规定它们之间必须有一个空格，在"——longoption"的情况下，空格将终止选项解析并将所有长选项转换为非选项参数。
getopt and getopts are different beasts, and people seem to have a bit of misunderstanding of what they do. getopts is a built-in command to bash to process command-line options in a loop and assign each found option and value in turn to built-in variables, so you can further process them. getopt, however, is an external utility program, and it doesn't actually process your options for you the way that e.g. bash getopts, the Perl Getopt module or the Python optparse/argparse modules do. All that getopt does is canonicalize the options that are passed in — i.e. convert them to a more standard form, so that it's easier for a shell script to process them. For example, an application of getopt might convert the following:
myscript -ab infile.txt -ooutfile.txt
到这个:
myscript -a -b -o outfile.txt infile.txt
你必须自己进行实际的处理。如果你对指定选项的方式做了各种限制，你根本不必使用getopt:
每个参数只放一个选项; 所有选项都在任何位置参数(即非选项参数)之前; 对于带值的选项(例如上面的-o)，值必须作为一个单独的参数(在空格之后)。
为什么使用getopt而不是getopts?基本原因是只有GNU getopt支持长名称的命令行选项(GNU getopt是Linux上的默认设置。Mac OS X和FreeBSD提供了一个基本的但不是很有用的getopt，但GNU版本可以安装;见下文)。
例如，这里有一个使用GNU getopt的例子，来自我的一个名为javawrap的脚本:
# NOTE: This requires GNU getopt. On Mac OS X and FreeBSD, you have to install this
# separately; see below.
TEMP=$(getopt -o vdm: --long verbose,debug,memory:,debugfile:,minheap:,maxheap: \
-n 'javawrap' -- "$@")
if [ $? != 0 ] ; then echo "Terminating..." >&2 ; exit 1 ; fi
# Note the quotes around '$TEMP': they are essential!
eval set -- "$TEMP"
VERBOSE=false
DEBUG=false
MEMORY=
DEBUGFILE=
JAVA_MISC_OPT=
while true; do
case "$1" in
-v | --verbose ) VERBOSE=true; shift ;;
-d | --debug ) DEBUG=true; shift ;;
-m | --memory ) MEMORY="$2"; shift 2 ;;
--debugfile ) DEBUGFILE="$2"; shift 2 ;;
--minheap )
JAVA_MISC_OPT="$JAVA_MISC_OPT -XX:MinHeapFreeRatio=$2"; shift 2 ;;
--maxheap )
JAVA_MISC_OPT="$JAVA_MISC_OPT -XX:MaxHeapFreeRatio=$2"; shift 2 ;;
-- ) shift; break ;;
* ) break ;;
esac
done
这让你可以指定诸如——verbose -dm4096——minh=20——maxhe 40——debugfi="/Users/John Johnson/debug.txt"之类的选项。调用getopt的效果是将选项规范化为——verbose -d -m 4096——minheap 20——maxheap 40——debugfile "/Users/John Johnson/debug.txt"，这样您就可以更容易地处理它们。“$1”和“$2”周围的引号很重要，因为它可以确保其中有空格的参数得到正确处理。
If you delete the first 9 lines (everything up through the eval set line), the code will still work! However, your code will be much pickier in what sorts of options it accepts: In particular, you'll have to specify all options in the "canonical" form described above. With the use of getopt, however, you can group single-letter options, use shorter non-ambiguous forms of long-options, use either the --file foo.txt or --file=foo.txt style, use either the -m 4096 or -m4096 style, mix options and non-options in any order, etc. getopt also outputs an error message if unrecognized or ambiguous options are found.
NOTE: There are actually two totally different versions of getopt, basic getopt and GNU getopt, with different features and different calling conventions.2 Basic getopt is quite broken: Not only does it not handle long options, it also can't even handle embedded spaces inside of arguments or empty arguments, whereas getopts does do this right. The above code will not work in basic getopt. GNU getopt is installed by default on Linux, but on Mac OS X and FreeBSD it needs to be installed separately. On Mac OS X, install MacPorts (http://www.macports.org) and then do sudo port install getopt to install GNU getopt (usually into /opt/local/bin), and make sure that /opt/local/bin is in your shell path ahead of /usr/bin. On FreeBSD, install misc/getopt.
为您自己的程序修改示例代码的快速指南:在前几行中，除了调用getopt的行外，其余都是“样板代码”，应该保持不变。您应该在-n之后更改程序名，在-o之后指定短选项，在——long之后指定长选项。在带值的选项后面加冒号。
最后，如果您看到的代码只是set而不是eval set，那么它是为BSD getopt编写的。您应该将其更改为使用eval set样式，这种样式适用于两个版本的getopt，而普通集不适用于GNU getopt。
实际上，ksh93中的getopts支持长名称选项，但是这个shell不像bash那样经常使用。在zsh中，使用zparseopts来获得这个功能。
从技术上讲，“GNU getopt”是一个用词不当的词;这个版本实际上是为Linux而不是GNU项目编写的。然而，它遵循所有的GNU约定，术语“GNU getopt”是常用的(例如在FreeBSD上)。
