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?
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
例如,如果所有长选项都有唯一且匹配的首字符作为短选项
./slamm --chaos 23 --plenty test -quiet
和
./slamm -c 23 -p test -q
你可以在getopts重写$args之前使用它:
# change long options to short options
for arg; do
[[ "${arg:0:1}" == "-" ]] && delim="" || delim="\""
if [ "${arg:0:2}" == "--" ];
then args="${args} -${arg:2:1}"
else args="${args} ${delim}${arg}${delim}"
fi
done
# reset the incoming args
eval set -- $args
# proceed as usual
while getopts ":b:la:h" OPTION; do
.....
谢谢mtvee的灵感;-)
其他回答
使用带有短/长选项和参数的getopts
适用于所有组合,例如:
Foobar -f——bar Foobar——foo -b Foobar -bf -bar - Foobar foobar -fbFBAshorty——bar -FB——arguments=longhorn foobar -fA "text shorty" -B——arguments="text longhorn" bash foobar -F—barfoo sh foobar - b——foobar -… bash ./foobar -F——bar
本例中的一些声明
Options=$@
Optnum=$#
sfoo='no '
sbar='no '
sfoobar='no '
sbarfoo='no '
sarguments='no '
sARG=empty
lfoo='no '
lbar='no '
lfoobar='no '
lbarfoo='no '
larguments='no '
lARG=empty
Usage函数看起来如何
function _usage()
{
###### U S A G E : Help and ERROR ######
cat <<EOF
foobar $Options
$*
Usage: foobar <[options]>
Options:
-b --bar Set bar to yes ($foo)
-f --foo Set foo to yes ($bart)
-h --help Show this message
-A --arguments=... Set arguments to yes ($arguments) AND get ARGUMENT ($ARG)
-B --barfoo Set barfoo to yes ($barfoo)
-F --foobar Set foobar to yes ($foobar)
EOF
}
[ $# = 0 ] && _usage " >>>>>>>> no options given "
具有长/短标志和长参数的getop
while getopts ':bfh-A:BF' OPTION ; do
case "$OPTION" in
b ) sbar=yes ;;
f ) sfoo=yes ;;
h ) _usage ;;
A ) sarguments=yes;sARG="$OPTARG" ;;
B ) sbarfoo=yes ;;
F ) sfoobar=yes ;;
- ) [ $OPTIND -ge 1 ] && optind=$(expr $OPTIND - 1 ) || optind=$OPTIND
eval OPTION="\$$optind"
OPTARG=$(echo $OPTION | cut -d'=' -f2)
OPTION=$(echo $OPTION | cut -d'=' -f1)
case $OPTION in
--foo ) lfoo=yes ;;
--bar ) lbar=yes ;;
--foobar ) lfoobar=yes ;;
--barfoo ) lbarfoo=yes ;;
--help ) _usage ;;
--arguments ) larguments=yes;lARG="$OPTARG" ;;
* ) _usage " Long: >>>>>>>> invalid options (long) " ;;
esac
OPTIND=1
shift
;;
? ) _usage "Short: >>>>>>>> invalid options (short) " ;;
esac
done
输出
##################################################################
echo "----------------------------------------------------------"
echo "RESULT short-foo : $sfoo long-foo : $lfoo"
echo "RESULT short-bar : $sbar long-bar : $lbar"
echo "RESULT short-foobar : $sfoobar long-foobar : $lfoobar"
echo "RESULT short-barfoo : $sbarfoo long-barfoo : $lbarfoo"
echo "RESULT short-arguments: $sarguments with Argument = \"$sARG\" long-arguments: $larguments and $lARG"
将上述内容组合成一个内聚脚本
#!/bin/bash
# foobar: getopts with short and long options AND arguments
function _cleanup ()
{
unset -f _usage _cleanup ; return 0
}
## Clear out nested functions on exit
trap _cleanup INT EXIT RETURN
###### some declarations for this example ######
Options=$@
Optnum=$#
sfoo='no '
sbar='no '
sfoobar='no '
sbarfoo='no '
sarguments='no '
sARG=empty
lfoo='no '
lbar='no '
lfoobar='no '
lbarfoo='no '
larguments='no '
lARG=empty
function _usage()
{
###### U S A G E : Help and ERROR ######
cat <<EOF
foobar $Options
$*
Usage: foobar <[options]>
Options:
-b --bar Set bar to yes ($foo)
-f --foo Set foo to yes ($bart)
-h --help Show this message
-A --arguments=... Set arguments to yes ($arguments) AND get ARGUMENT ($ARG)
-B --barfoo Set barfoo to yes ($barfoo)
-F --foobar Set foobar to yes ($foobar)
EOF
}
[ $# = 0 ] && _usage " >>>>>>>> no options given "
##################################################################
####### "getopts" with: short options AND long options #######
####### AND short/long arguments #######
while getopts ':bfh-A:BF' OPTION ; do
case "$OPTION" in
b ) sbar=yes ;;
f ) sfoo=yes ;;
h ) _usage ;;
A ) sarguments=yes;sARG="$OPTARG" ;;
B ) sbarfoo=yes ;;
F ) sfoobar=yes ;;
- ) [ $OPTIND -ge 1 ] && optind=$(expr $OPTIND - 1 ) || optind=$OPTIND
eval OPTION="\$$optind"
OPTARG=$(echo $OPTION | cut -d'=' -f2)
OPTION=$(echo $OPTION | cut -d'=' -f1)
case $OPTION in
--foo ) lfoo=yes ;;
--bar ) lbar=yes ;;
--foobar ) lfoobar=yes ;;
--barfoo ) lbarfoo=yes ;;
--help ) _usage ;;
--arguments ) larguments=yes;lARG="$OPTARG" ;;
* ) _usage " Long: >>>>>>>> invalid options (long) " ;;
esac
OPTIND=1
shift
;;
? ) _usage "Short: >>>>>>>> invalid options (short) " ;;
esac
done
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。
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
我只是偶尔写一些shell脚本,但没有实践经验,所以任何反馈都很感激。
使用@Arvid Requate提出的策略,我们注意到一些用户错误。忘记包含值的用户会意外地将下一个选项的名称视为值:
./getopts_test.sh --loglevel= --toc=TRUE
将导致"loglevel"的值被视为"——toc=TRUE"。这可以 被避免的。
我从http://mwiki.wooledge.org/BashFAQ/035关于手动解析的讨论中改编了一些关于检查CLI用户错误的想法。我在处理"-"和"——"参数时插入了错误检查。
然后我开始摆弄语法,所以这里的任何错误都是我的错,而不是原始作者的错。
我的方法可以帮助那些喜欢输入带等号或不带等号的长字符的用户。也就是说,它对“——loglevel 9”的响应应该与“——loglevel=9”的响应相同。在——/space方法中,不可能确定用户是否忘记了一个参数,因此需要进行一些猜测。
如果用户使用长/等号格式(——opt=),则=后的空格会触发错误,因为没有提供参数。 如果user有长/空格参数(——opt),如果后面没有参数(命令结束)或参数以破折号开头,该脚本将导致失败。
In case you are starting out on this, there is an interesting difference between "--opt=value" and "--opt value" formats. With the equal sign, the command line argument is seen as "opt=value" and the work to handle that is string parsing, to separate at the "=". In contrast, with "--opt value", the name of the argument is "opt" and we have the challenge of getting the next value supplied in the command line. That's where @Arvid Requate used ${!OPTIND}, the indirect reference. I still don't understand that, well, at all, and comments in BashFAQ seem to warn against that style (http://mywiki.wooledge.org/BashFAQ/006). BTW, I don't think previous poster's comments about importance of OPTIND=$(( $OPTIND + 1 )) are correct. I mean to say, I see no harm from omitting it.
在该脚本的最新版本中,flag -v表示详细打印输出。
将其保存在一个名为“cli-5.sh”的文件中,使其可执行,其中任何一个都将以预期的方式工作或失败
./cli-5.sh -v --loglevel=44 --toc TRUE
./cli-5.sh -v --loglevel=44 --toc=TRUE
./cli-5.sh --loglevel 7
./cli-5.sh --loglevel=8
./cli-5.sh -l9
./cli-5.sh --toc FALSE --loglevel=77
./cli-5.sh --toc=FALSE --loglevel=77
./cli-5.sh -l99 -t yyy
./cli-5.sh -l 99 -t yyy
下面是对用户intpu进行错误检查的示例输出
$ ./cli-5.sh --toc --loglevel=77
ERROR: toc value must not have dash at beginning
$ ./cli-5.sh --toc= --loglevel=77
ERROR: value for toc undefined
您应该考虑打开-v,因为它会打印OPTIND和OPTARG的内部内容
#/usr/bin/env bash
## Paul Johnson
## 20171016
##
## Combines ideas from
## https://stackoverflow.com/questions/402377/using-getopts-in-bash-shell-script-to-get-long-and-short-command-line-options
## by @Arvid Requate, and http://mwiki.wooledge.org/BashFAQ/035
# What I don't understand yet:
# In @Arvid REquate's answer, we have
# val="${!OPTIND}"; OPTIND=$(( $OPTIND + 1 ))
# this works, but I don't understand it!
die() {
printf '%s\n' "$1" >&2
exit 1
}
printparse(){
if [ ${VERBOSE} -gt 0 ]; then
printf 'Parse: %s%s%s\n' "$1" "$2" "$3" >&2;
fi
}
showme(){
if [ ${VERBOSE} -gt 0 ]; then
printf 'VERBOSE: %s\n' "$1" >&2;
fi
}
VERBOSE=0
loglevel=0
toc="TRUE"
optspec=":vhl:t:-:"
while getopts "$optspec" OPTCHAR; do
showme "OPTARG: ${OPTARG[*]}"
showme "OPTIND: ${OPTIND[*]}"
case "${OPTCHAR}" in
-)
case "${OPTARG}" in
loglevel) #argument has no equal sign
opt=${OPTARG}
val="${!OPTIND}"
## check value. If negative, assume user forgot value
showme "OPTIND is {$OPTIND} {!OPTIND} has value \"${!OPTIND}\""
if [[ "$val" == -* ]]; then
die "ERROR: $opt value must not have dash at beginning"
fi
## OPTIND=$(( $OPTIND + 1 )) # CAUTION! no effect?
printparse "--${OPTARG}" " " "${val}"
loglevel="${val}"
shift
;;
loglevel=*) #argument has equal sign
opt=${OPTARG%=*}
val=${OPTARG#*=}
if [ "${OPTARG#*=}" ]; then
printparse "--${opt}" "=" "${val}"
loglevel="${val}"
## shift CAUTION don't shift this, fails othewise
else
die "ERROR: $opt value must be supplied"
fi
;;
toc) #argument has no equal sign
opt=${OPTARG}
val="${!OPTIND}"
## check value. If negative, assume user forgot value
showme "OPTIND is {$OPTIND} {!OPTIND} has value \"${!OPTIND}\""
if [[ "$val" == -* ]]; then
die "ERROR: $opt value must not have dash at beginning"
fi
## OPTIND=$(( $OPTIND + 1 )) #??
printparse "--${opt}" " " "${val}"
toc="${val}"
shift
;;
toc=*) #argument has equal sign
opt=${OPTARG%=*}
val=${OPTARG#*=}
if [ "${OPTARG#*=}" ]; then
toc=${val}
printparse "--$opt" " -> " "$toc"
##shift ## NO! dont shift this
else
die "ERROR: value for $opt undefined"
fi
;;
help)
echo "usage: $0 [-v] [--loglevel[=]<value>] [--toc[=]<TRUE,FALSE>]" >&2
exit 2
;;
*)
if [ "$OPTERR" = 1 ] && [ "${optspec:0:1}" != ":" ]; then
echo "Unknown option --${OPTARG}" >&2
fi
;;
esac;;
h|-\?|--help)
## must rewrite this for all of the arguments
echo "usage: $0 [-v] [--loglevel[=]<value>] [--toc[=]<TRUE,FALSE>]" >&2
exit 2
;;
l)
loglevel=${OPTARG}
printparse "-l" " " "${loglevel}"
;;
t)
toc=${OPTARG}
;;
v)
VERBOSE=1
;;
*)
if [ "$OPTERR" != 1 ] || [ "${optspec:0:1}" = ":" ]; then
echo "Non-option argument: '-${OPTARG}'" >&2
fi
;;
esac
done
echo "
After Parsing values
"
echo "loglevel $loglevel"
echo "toc $toc"
长选项可以被内置的标准getopts作为- " option "的"参数"解析。
这是可移植的本地POSIX shell -不需要外部程序或bashisms。
本指南将长选项作为-选项的参数实现,因此——alpha被getopts视为参数alpha为-,而——bravo=foo被参数bravo=foo视为-。true实参通过shell参数展开获取,更新$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。