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Accepted
Baran Aldemir
Asked: 2021-11-15 10:33:42 +0800 CST

如何有效地检查给 bash 脚本的参数？

  • 772

我写了一个 bash 脚本，但由于我是一个自学的 bash 菜鸟，我想问我是否可以更有效地检查给定的参数。我也用谷歌搜索过这个并检查了这里的主题，但到目前为止我看到的例子太复杂了。在 python3 中，有很多更简单的方法，但我想在 bash 中它有点复杂。

#!/bin/bash

ERR_MSG="You did not give the argument required"

if [[ ${1?$ERR_MSG} == "a" ]]; then
        echo "ABC"
elif [[ ${1?$ERR_MSG} == "b" ]]; then
        echo "123"
elif [[ ${1?$ERR_MSG} == "c" ]]; then
        echo ".*?"
else
    echo "You did not provide the argument correctly"
    exit 1
fi
bash arguments

2 个回答

  1. 只接受一个参数的脚本，该参数必须是a、b或c：

    #!/bin/bash

if [[ $# -ne 1 ]]; then
    echo 'Too many/few arguments, expecting one' >&2
    exit 1
fi

case $1 in
    a|b|c)  # Ok
        ;;
    *)
        # The wrong first argument.
        echo 'Expected "a", "b", or "c"' >&2
        exit 1
esac

# rest of code here

    如果您想进行正确的选项解析并希望接受-a, -b, 或-c作为不带参数-d的选项，以及作为带参数的选项。

    #!/bin/bash

# Default values:
opt_a=false
opt_b=false
opt_c=false
opt_d='no value given'

# It's the : after d that signifies that it takes an option argument.

while getopts abcd: opt; do
    case $opt in
        a) opt_a=true ;;
        b) opt_b=true ;;
        c) opt_c=true ;;
        d) opt_d=$OPTARG ;;
        *) echo 'error in command line parsing' >&2
           exit 1
    esac
done

shift "$(( OPTIND - 1 ))"

# Command line parsing is done now.
# The code below acts on the used options.
# This code would typically do sanity checks,
# like emitting errors for incompatible options, 
# missing options etc.

"$opt_a" && echo 'Got the -a option'
"$opt_b" && echo 'Got the -b option'
"$opt_c" && echo 'Got the -c option'

printf 'Option -d: %s\n' "$opt_d"

if [[ $# -gt 0 ]]; then
    echo 'Further operands:'
    printf '\t%s\n' "$@"
fi

# The rest of your code goes here.

    测试：

    $ ./script -d 'hello bumblebee' -ac
Got the -a option
Got the -c option
Option -d: hello bumblebee

    $ ./script
Option -d: no value given

    $ ./script -q
script: illegal option -- q
error in command line parsing

    $ ./script -adboo 1 2 3
Got the -a option
Option -d: boo
Further operands:
        1
        2
        3

    选项解析在第一个非选项参数处终止，或者在--. 请注意，因为-d需要一个参数，-a所以在以下示例中被视为该参数：

    $ ./script -d -a -- -c -b
Option -d: -a
Further operands:
        -c
        -b
    • 1
  2. Best Answer

    将此代码复制到文件中。（不要忘记chmod +x）这应该可以满足您的需求。

    #!/bin/bash
VERSION="0.0.1"
ACCEPTED_SERVER="server"
ACCEPTED_USER="user"

usage()
{
    echo " $(basename $0) [-v] [-h] -u user -s server"
    exit
}

version()
{
    echo "Current version: $VERSION"
}

get_opts()
{
    while [[ $# -gt 0 ]]
    do
        key="$1"
        case $key in
            -u|--user)
                shift
                USER="$1"
                shift
                ;;
            -s|--server)
                shift
                SERVER="$1"
                shift
                ;;
            -h|--help)
                usage
                exit
                ;;
            -v|--version)
                version
                exit
            ;;
        esac
    done
}

# echo " arguments: $#"
get_opts $*
if [ $# -gt 4 ] || [ $# -lt 1 ]; then
    usage
fi
echo "$SERVER -- $ACCEPTED_SERVER"
if ! [ "$SERVER" = "$ACCEPTED_SERVER" ]; then
    echo "Wrong server: $SERVER"
    echo "Try with user: $ACCEPTED_SERVER"
    usage
else
    echo "Correct server: $SERVER"

fi
if ! [ "$USER" = "$ACCEPTED_USER" ]; then
    echo "Wrong user: $USER"
    echo "Try with user: $ACCEPTED_USER"
    usage
else
    echo "Correct user: $USER"
fi

echo "Correct! - Server: $SERVER - User: $USER"

    然后可以添加功能用法、版本等。

    usage()
{
    echo "[-v] [-h] [-u user] [-s server] task"
}
    • -1

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