解析 bash 脚本中的参数/选项/标志

发布于 2024-12-17 05:49:39 字数 452 浏览 3 评论 0原文

我正在尝试解析 bash 脚本中的选项。如何使用 getopts 来查看是否已输入可选标志。

FILE1=$1
FILE2=$2
outputfile=''
while getopts "o" OPTION
do
    case $OPTION in
    o)
       outputfile=$OPTARG
    ;;
    esac
done
if [ ! $outputfile -eq '' ]
then
    cat $FILE1 | paste - | $FILE1 - | tr "\t" "\n" | paste $FILE1 $FILE2 | tr '\t' '\n' > $outputfile

else
    cat $FILE1 | paste - | $FILE1 - | tr "\t" "\n" 
    paste $FILE1 $FILE2 | tr '\t' '\n' 
fi

原文

I am trying to parse an option in a bash script. how can I use getopts to see whether an optional flag has been entered.

FILE1=$1
FILE2=$2
outputfile=''
while getopts "o" OPTION
do
    case $OPTION in
    o)
       outputfile=$OPTARG
    ;;
    esac
done
if [ ! $outputfile -eq '' ]
then
    cat $FILE1 | paste - | $FILE1 - | tr "\t" "\n" | paste $FILE1 $FILE2 | tr '\t' '\n' > $outputfile

else
    cat $FILE1 | paste - | $FILE1 - | tr "\t" "\n" 
    paste $FILE1 $FILE2 | tr '\t' '\n' 
fi

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清眉祭 2024-12-24 05:49:39

这里存在很多问题。您需要首先解析选项（getopts循环），然后从参数列表中删除它们（使用shift $(($OPTIND-1))），然后获取FILE1和 FILE2 来自 $1 和 $2。其次，您需要告诉 getopts -o 接受一个参数（getopts "o:"）。第三，您的 getopts 循环应包括检查无效选项（并且您可能还应确保指定了 FILE1 和 FILE2）。第四，在检查 $outputfile 是否为空时，需要用双引号括起来，然后使用字符串测试（-eq 检查数字是否相等，如果使用它来比较数字以外的任何内容，则会给出错误）。第五，文件名应该用双引号引起来，以防其中有任何有趣的字符。最后，您尝试执行的实际命令（paste、tr 等）没有意义（所以我几乎不理会它们）。这是我重写的机会：

#!/bin/sh
outputfile=''
while getopts "o:" OPTION
do
    case $OPTION in
    o)
        outputfile="$OPTARG"
    ;;
    [?])
        echo "Usage: $0 [-o outfile] file1 file2" >&2
        exit 1
    ;;
    esac
done
shift $(($OPTIND-1))

if [ $# -ne 2 ]; then
    echo "Usage: $0 [-o outfile] file1 file2" >&2
    exit 1
fi
FILE1="$1"
FILE2="$2"

if [ -n "$outputfile" ]; then
    cat "$FILE1" | paste - | "$FILE1" - | tr "\t" "\n" | paste "$FILE1" "$FILE2" | tr '\t' '\n' > "$outputfile"
else
    cat "$FILE1" | paste - | "$FILE1" - | tr "\t" "\n"
    paste "$FILE1" "$FILE2" | tr '\t' '\n'
fi

There are a number of problems here. You need to parse options (the getopts loop) first, then remove them from the argument list (with shift $(($OPTIND-1))), then get FILE1 and FILE2 from $1 and $2. Second, you need to tell getopts that -o takes an argument (getopts "o:"). Third, your getopts loop should include checking for an invalid option (and you should probably also make sure both FILE1 and FILE2 were specified). Fourth, when checking whether $outputfile is blank, you need double-quotes around it and then use a string test (-eq checks for numeric equality, and will give an error if you use it to compare anything other than numbers). Fifth, you should have double-quotes around the filenames in case they have any funny characters in them. Finally, the actual commands you're trying to execute (paste, tr, etc) don't make sense (so I pretty much left them alone). Here's my shot at a rewrite:

#!/bin/sh
outputfile=''
while getopts "o:" OPTION
do
    case $OPTION in
    o)
        outputfile="$OPTARG"
    ;;
    [?])
        echo "Usage: $0 [-o outfile] file1 file2" >&2
        exit 1
    ;;
    esac
done
shift $(($OPTIND-1))

if [ $# -ne 2 ]; then
    echo "Usage: $0 [-o outfile] file1 file2" >&2
    exit 1
fi
FILE1="$1"
FILE2="$2"

if [ -n "$outputfile" ]; then
    cat "$FILE1" | paste - | "$FILE1" - | tr "\t" "\n" | paste "$FILE1" "$FILE2" | tr '\t' '\n' > "$outputfile"
else
    cat "$FILE1" | paste - | "$FILE1" - | tr "\t" "\n"
    paste "$FILE1" "$FILE2" | tr '\t' '\n'
fi

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