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

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。

其他回答

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"

下面你可以找到bash中复杂选项解析的几种不同方法: http://mywiki.wooledge.org/ComplexOptionParsing

我确实创建了下面的一个,而且我认为它很好,因为它的代码最少 多头和空头选择都有效。使用这种方法,长选项也可以有多个参数。

#!/bin/bash
# Uses bash extensions.  Not portable as written.

declare -A longoptspec
longoptspec=( [loglevel]=1 ) #use associative array to declare how many arguments a long option expects, in this case we declare that loglevel expects/has one argument, long options that aren't listed i n this way will have zero arguments by default
optspec=":h-:"
while getopts "$optspec" opt; do
while true; do
    case "${opt}" in
        -) #OPTARG is name-of-long-option or name-of-long-option=value
            if [[ "${OPTARG}" =~ .*=.* ]] #with this --key=value format only one argument is possible
            then
                opt=${OPTARG/=*/}
                OPTARG=${OPTARG#*=}
                ((OPTIND--))    
            else #with this --key value1 value2 format multiple arguments are possible
                opt="$OPTARG"
                OPTARG=(${@:OPTIND:$((longoptspec[$opt]))})
            fi
            ((OPTIND+=longoptspec[$opt]))
            continue #now that opt/OPTARG are set we can process them as if getopts would've given us long options
            ;;
        loglevel)
          loglevel=$OPTARG
            ;;
        h|help)
            echo "usage: $0 [--loglevel[=]<value>]" >&2
            exit 2
            ;;
    esac
break; done
done

# End of file

我还没有足够的代表来评论或投票他的解决方案,但他的答案对我来说非常有效。我遇到的唯一问题是参数以单引号结尾(所以我把它们去掉了)。

我还添加了一些示例用法和帮助文本。我将在这里附上我略微扩展的版本:

#!/bin/bash

# getopt example
# from: https://stackoverflow.com/questions/402377/using-getopts-in-bash-shell-script-to-get-long-and-short-command-line-options
HELP_TEXT=\
"   USAGE:\n
    Accepts - and -- flags, can specify options that require a value, and can be in any order. A double-hyphen (--) will stop processing options.\n\n

    Accepts the following forms:\n\n

    getopt-example.sh -a -b -c value-for-c some-arg\n
    getopt-example.sh -c value-for-c -a -b some-arg\n
    getopt-example.sh -abc some-arg\n
    getopt-example.sh --along --blong --clong value-for-c -a -b -c some-arg\n
    getopt-example.sh some-arg --clong value-for-c\n
    getopt-example.sh
"

aflag=false
bflag=false
cargument=""

# options may be followed by one colon to indicate they have a required argument
if ! options=$(getopt -o abc:h\? -l along,blong,help,clong: -- "$@")
then
    # something went wrong, getopt will put out an error message for us
    exit 1
fi

set -- $options

while [ $# -gt 0 ]
do
    case $1 in
    -a|--along) aflag=true ;;
    -b|--blong) bflag=true ;;
    # for options with required arguments, an additional shift is required
    -c|--clong) cargument="$2" ; shift;;
    -h|--help|-\?) echo -e $HELP_TEXT; exit;;
    (--) shift; break;;
    (-*) echo "$0: error - unrecognized option $1" 1>&2; exit 1;;
    (*) break;;
    esac
    shift
done

# to remove the single quotes around arguments, pipe the output into:
# | sed -e "s/^'\\|'$//g"  (just leading/trailing) or | sed -e "s/'//g"  (all)

echo aflag=${aflag}
echo bflag=${bflag}
echo cargument=${cargument}

while [ $# -gt 0 ]
do
    echo arg=$1
    shift

    if [[ $aflag == true ]]; then
        echo a is true
    fi

done

我研究那个课题已经很长时间了。并制作了我自己的库,你将需要在你的主脚本的来源。 有关示例,请参见libopt4shell和cd2mpc。 希望能有所帮助!

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

./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;-)