更简单地处理 shell 脚本选项

更简单地处理 shell 脚本选项

我正在寻找比 getopt/getopts 更干净、更“自记录”的处理 shell 脚本参数的方法。

它需要提供...

  • 完全支持“=”或“ ”(空格)后带或不带值的长选项。
  • 正确处理连字符选项名称(即 --ignore-case)
  • 正确处理带引号的选项值(即--text“文本字符串”)

我想消除 getopt/getopts 所需的嵌入 case 语句的大循环的开销,并将选项处理减少到类似......

option=argumentparse "$@"
[[ option == ""           ]] && helpShow
[[ option =~ -h|--help    ]] && helpShow
[[ option =~ -v|--version ]] && versionShow
[[ option =~ -G|--GUI     ]] && GUI=$TRUE
[[ option =~ --title      ]] && TITLE=${option["--title"]}

在这里,argumentparse() 函数将各种语法可能性解析为一致的格式,可能是关联数组。

一定有什么东西被编码在某个地方。有任何想法吗?

(更新并重新命名)

答案1

由于这个问题已经被浏览了很多(至少对我来说)但没有提交答案,所以传递所采用的解决方案......

笔记
某些函数(例如多接口输出函数ifHelpShow()uiShow()已被使用,但未包含在此处,因为它们的调用包含相关信息,但它们的实现不包含相关信息。

###############################################################################
# FUNCTIONS (bash 4.1.0)
###############################################################################

function isOption () {
  # isOption "$@"
  # Return true (0) if argument has 1 or more leading hyphens.
  # Example:
  #     isOption "$@"  && ...
  # Note:
  #   Cannot use ifHelpShow() here since cannot distinguish 'isOption --help'
  #   from 'isOption "$@"' where first argument in "$@" is '--help'
  # Revised:
  #     20140117 docsalvage
  # 
  # support both short and long options
  [[ "${1:0:1}" == "-" ]]  && return 0
  return 1
}

function optionArg () {
  ifHelpShow "$1" 'optionArg  --option "$@"
    Echo argument to option if any. Within "$@", option and argument may be separated
    by space or "=". Quoted strings are preserved. If no argument, nothing echoed.
    Return true (0) if option is in argument list, whether an option-argument supplied
    or not. Return false (1) if option not in argument list. See also option().
    Examples:
        FILE=$(optionArg --file "$1")
        if $(optionArg -f "$@"); then ...
        optionArg --file "$@"   && ...
    Revised:
        20140117 docsalvage'  && return
  #
  # --option to find (without '=argument' if any)
  local FINDOPT="$1"; shift
  local OPTION=""
  local ARG=
  local o=
  local re="^$FINDOPT="
  #
  # echo "option start: FINDOPT=$FINDOPT, o=$o, OPTION=$OPTION, ARG=$ARG, @=$@" >&2
  #
  # let "$@" split commandline, respecting quoted strings
  for o in "$@"
  do
    # echo "FINDOPT=$FINDOPT, o=$o, OPTION=$OPTION, ARG=$ARG" >&2
    # echo " o=$o"  >&2
    # echo "re=$re" >&2
    #
    # detect --option and handle --option=argument
    [[ $o =~ $re ]]  && { OPTION=$FINDOPT; ARG="${o/$FINDOPT=/}"; break; }
    #
    # $OPTION will be non-null if --option was detected in last pass through loop
    [[ ! $OPTION ]]  && [[ "$o" != $FINDOPT ]]   && {              continue; } # is a positional arg (no previous --option)
    [[ ! $OPTION ]]  && [[ "$o" == $FINDOPT ]]   && { OPTION="$o"; continue; } # is the arg to last --option
    [[   $OPTION ]]  &&   isOption "$o"          && {                 break; } # no more arguments
    [[   $OPTION ]]  && ! isOption "$o"          && { ARG="$o";       break; } # only allow 1 argument
  done
  #
  # echo "option  final: FINDOPT=$FINDOPT, o=$o, OPTION=$OPTION, ARG=$ARG, @=$@" >&2
  #
  # use '-n' to remove any blank lines
  echo -n "$ARG"
  [[ "$OPTION" == "$FINDOPT" ]]   && return 0
  return 1
}

###############################################################################
# MAIN  (bash 4.1.0) (excerpt of relevant lines)
###############################################################################

# options
[[ "$@" == ""            ]]   && { zimdialog --help           ; exit 0; }
[[ "$1" == "--help"      ]]   && { zimdialog --help           ; exit 0; }
[[ "$1" == "--version"   ]]   && { uiShow "version $VERSION\n"; exit 0; }

# options with arguments
TITLE="$(optionArg --title  "$@")"
TIP="$(  optionArg --tip    "$@")"
FILE="$( optionArg --file   "$@")"

答案2

这里有一个很好的答案,但OP明确要求更简单处理命令行选项。我认为没有比使用getoptfrom更简单的解析复杂 shell 选项的方法了实用程序Linux:

$ cat opts.sh 
#!/bin/bash

# Print usage and exit
usage() {
    exec >&2 # Write everything to STDERR (consistent with getopt errors)
    (($#)) && echo "$@"
    echo "Usage: $0 [opts...] [args...]"
    exit 1
}

# Use getopt to validate options and reorder them. On error print usage
OPTS=$(getopt -s bash -o 'ab:c' -l 'longopt,longopt2,longwitharg:' -- "$@") || usage

# Replace our arguments with the reordered version
eval set -- "$OPTS"

# At this point everything up to "--" is options
declare opt_a opt_c longopt longopt2 longwitharg
declare -a opt_b  # Array to accumulate -b arguments
while (($#))
do
    case $1 in
        -a) opt_a=1;;
        -b) opt_b+=("$2"); shift;;
        -c) ((++opt_c));;
        --longopt) longopt=1;;
        --longopt2) ((++longopt2));;
        --longwitharg) longwitharg=$2; shift;;
        --) shift; break;; # We're done with options, shift over "--" and move on...
        *) usage "Unknown argument: $1" # Should not happen unless getopt errors are ignored.
    esac
    # Always shift once (for options with arguments we already shifted in the case so it's the 2nd shift)
    shift
done

echo "Remaining arguments after parsing options: $#"
# Now you can work directly with "$@" or slurp it in an array
args=("$@")

# Here's what we're left with:
declare -p opt_a opt_b opt_c longopt longopt2 longwitharg

# This is how you iterate over an array which may contain spaces and other field separators
for file in "${args[@]}"
do
    echo "File arg: $file"
done

getopt将进行验证并返回错误(除非您告诉它不要这样做,否则您可以自己捕获它们)。例如:

$ ./opts.sh --badopt
getopt: unrecognized option '--badopt'

其他所有内容均已正确订购和引用:

$ ./opts.sh -ab3 -b8 file1 -ccc --longopt --longwitharg=abc --longwitharg "abc def" "file with spaces" 
Remaining arguments after parsing options: 2
declare -- opt_a="1"
declare -a opt_b=([0]="3" [1]="8")
declare -- opt_c="3"
declare -- longopt="1"
declare -- longopt2
declare -- longwitharg="abc def"
File arg: file1
File arg: file with spaces

这里的论点:

  • -a是一个标志 - 如果存在则设置为 1
  • -b并重复,每个实例都被添加到opt_b数组中
  • -c是一个计数器,计算 3 次出现的次数
  • --longopt是一个像这样的标志-a
  • --longopt2是一个类似的计数器-c(本例中未使用,因此未设置;在算术扩展)。
  • --longwitharg是一个带参数的正常选项。在此示例中,我们稍后在命令行上覆盖其值
  • file1和是剩余的参数,尽管它们是在随机位置指定的,但在getopt 对命令行重新排序file with spaces后,它们都会出现在末尾。--

请注意,引用变量对于正确处理带空格的参数非常重要,尽管我自愿避免在不需要的地方使用引号,例如:

  • 直接变量赋值:longwitharg=$2
  • 开关盒:case $1 in

如果不确定,额外的引号通常不会有什么坏处。

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