比如,我有一个脚本,用这行代码调用:

./myscript -vfd ./foo/bar/someFile -o /fizz/someOtherFile

或者这个:

./myscript -v -f -d -o /fizz/someOtherFile ./foo/bar/someFile 

什么是公认的解析方式,以便在每种情况下(或两者的某种组合)$v、$f和$d都将设置为true,而$outFile将等于/fiz/someOtherFile?


当前回答

混合位置和基于标志的参数

--param=arg(等于分隔符)

在位置参数之间自由混合标志:

./script.sh dumbo 127.0.0.1 --environment=production -q -d
./script.sh dumbo --environment=production 127.0.0.1 --quiet -d

可以用相当简洁的方法完成:

# process flags
pointer=1
while [[ $pointer -le $# ]]; do
   param=${!pointer}
   if [[ $param != "-"* ]]; then ((pointer++)) # not a parameter flag so advance pointer
   else
      case $param in
         # paramter-flags with arguments
         -e=*|--environment=*) environment="${param#*=}";;
                  --another=*) another="${param#*=}";;

         # binary flags
         -q|--quiet) quiet=true;;
                 -d) debug=true;;
      esac

      # splice out pointer frame from positional list
      [[ $pointer -gt 1 ]] \
         && set -- ${@:1:((pointer - 1))} ${@:((pointer + 1)):$#} \
         || set -- ${@:((pointer + 1)):$#};
   fi
done

# positional remain
node_name=$1
ip_address=$2

--参数arg(空格分隔)

通常情况下,不混合--flag=value和--flag值样式会更清晰。

./script.sh dumbo 127.0.0.1 --environment production -q -d

这读起来有点冒险,但仍然有效

./script.sh dumbo --environment production 127.0.0.1 --quiet -d

来源

# process flags
pointer=1
while [[ $pointer -le $# ]]; do
   if [[ ${!pointer} != "-"* ]]; then ((pointer++)) # not a parameter flag so advance pointer
   else
      param=${!pointer}
      ((pointer_plus = pointer + 1))
      slice_len=1

      case $param in
         # paramter-flags with arguments
         -e|--environment) environment=${!pointer_plus}; ((slice_len++));;
                --another) another=${!pointer_plus}; ((slice_len++));;

         # binary flags
         -q|--quiet) quiet=true;;
                 -d) debug=true;;
      esac

      # splice out pointer frame from positional list
      [[ $pointer -gt 1 ]] \
         && set -- ${@:1:((pointer - 1))} ${@:((pointer + $slice_len)):$#} \
         || set -- ${@:((pointer + $slice_len)):$#};
   fi
done

# positional remain
node_name=$1
ip_address=$2

其他回答

当我尝试这个问题时,上面的答案似乎有点bug——这是我发现更强大的解决方案:

boolean_arg=""
arg_with_value=""

while [[ $# -gt 0 ]]
do
key="$1"
case $key in
    -b|--boolean-arg)
    boolean_arg=true
    shift
    ;;
    -a|--arg-with-value)
    arg_with_value="$2"
    shift
    shift
    ;;
    -*)
    echo "Unknown option: $1"
    exit 1
    ;;
    *)
    arg_num=$(( $arg_num + 1 ))
    case $arg_num in
        1)
        first_normal_arg="$1"
        shift
        ;;
        2)
        second_normal_arg="$1"
        shift
        ;;
        *)
        bad_args=TRUE
    esac
    ;;
esac
done

# Handy to have this here when adding arguments to
# see if they're working. Just edit the '0' to be '1'.
if [[ 0 == 1 ]]; then
    echo "first_normal_arg: $first_normal_arg"
    echo "second_normal_arg: $second_normal_arg"
    echo "boolean_arg: $boolean_arg"
    echo "arg_with_value: $arg_with_value"
    exit 0
fi

if [[ $bad_args == TRUE || $arg_num < 2 ]]; then
    echo "Usage: $(basename "$0") <first-normal-arg> <second-normal-arg> [--boolean-arg] [--arg-with-value VALUE]"
    exit 1
fi

我使用optget和optgets的组合来解析带或不带参数的短选项和长选项,甚至是非选项(不带-或-的选项):

# catch wrong options and move non-options to the end of the string
args=$(getopt -l "$opt_long" "$opt_short" "$@" 2> >(sed -e 's/^/stderr/g')) || echo -n "Error: " && echo "$args" | grep -oP "(?<=^stderr).*" && exit 1
mapfile -t args < <(xargs -n1 <<< "$(echo "$args" | sed -E "s/(--[^ ]+) /\1=/g")" )
set -- "${args[@]}"

# parse short and long options
while getopts "$opt_short-:" opt; do
  ...
done

# remove all parsed options from $@
shift $((OPTIND-1)

这样,我就可以使用$opt_verbose这样的变量访问所有选项,而非选项可以通过默认变量$1、$2等访问:

echo "help:$opt_help"
echo "file:$opt_file"
echo "verbose:$opt_verbose"
echo "long_only:$opt_long_only"
echo "short_only:$opt_s"
echo "path:$1"
echo "mail:$2"

其中一个主要特点是,我能够以完全随机的顺序传递所有选项和非选项:

#             $opt_file     $1        $2          $opt_... $opt_... $opt_...
# /demo.sh --file=file.txt /dir info@example.com -V -h --long_only=yes -s
help:1
file:file.txt
verbose:1
long_only:yes
short_only:1
path:/dir
mail:info@example.com

更多详情:https://stackoverflow.com/a/74275254/318765

这里有一个getopts,它用最少的代码实现解析,并允许您在一种情况下使用eval和substring定义要提取的内容。

基本上eval“local key='val'”

function myrsync() {

        local backup=("${@}") args=(); while [[ $# -gt 0 ]]; do k="$1";
                case "$k" in
                    ---sourceuser|---sourceurl|---targetuser|---targeturl|---file|---exclude|---include)
                        eval "local ${k:3}='${2}'"; shift; shift    # Past two arguments
                    ;;
                    *)  # Unknown option  
                        args+=("$1"); shift;                        # Past argument only
                    ;;                                              
                esac                                                
        done; set -- "${backup[@]}"                                 # Restore $@


        echo "${sourceurl}"
}

在这里,将变量声明为局部变量,而不是全局变量。

调用为:

myrsync ---sourceurl http://abc.def.g ---sourceuser myuser ... 

${k:3}基本上是一个从键中删除第一个---的子字符串。

Bash空格分隔(例如--option参数)

cat >/tmp/demo-space-separated.sh <<'EOF'
#!/bin/bash

POSITIONAL_ARGS=()

while [[ $# -gt 0 ]]; do
  case $1 in
    -e|--extension)
      EXTENSION="$2"
      shift # past argument
      shift # past value
      ;;
    -s|--searchpath)
      SEARCHPATH="$2"
      shift # past argument
      shift # past value
      ;;
    --default)
      DEFAULT=YES
      shift # past argument
      ;;
    -*|--*)
      echo "Unknown option $1"
      exit 1
      ;;
    *)
      POSITIONAL_ARGS+=("$1") # save positional arg
      shift # past argument
      ;;
  esac
done

set -- "${POSITIONAL_ARGS[@]}" # restore positional parameters

echo "FILE EXTENSION  = ${EXTENSION}"
echo "SEARCH PATH     = ${SEARCHPATH}"
echo "DEFAULT         = ${DEFAULT}"
echo "Number files in SEARCH PATH with EXTENSION:" $(ls -1 "${SEARCHPATH}"/*."${EXTENSION}" | wc -l)

if [[ -n $1 ]]; then
    echo "Last line of file specified as non-opt/last argument:"
    tail -1 "$1"
fi
EOF

chmod +x /tmp/demo-space-separated.sh

/tmp/demo-space-separated.sh -e conf -s /etc /etc/hosts

复制粘贴上面的块的输出

FILE EXTENSION  = conf
SEARCH PATH     = /etc
DEFAULT         =
Number files in SEARCH PATH with EXTENSION: 14
Last line of file specified as non-opt/last argument:
#93.184.216.34    example.com

用法

demo-space-separated.sh -e conf -s /etc /etc/hosts

Bash等于分隔符(例如,--option=argument)

cat >/tmp/demo-equals-separated.sh <<'EOF'
#!/bin/bash

for i in "$@"; do
  case $i in
    -e=*|--extension=*)
      EXTENSION="${i#*=}"
      shift # past argument=value
      ;;
    -s=*|--searchpath=*)
      SEARCHPATH="${i#*=}"
      shift # past argument=value
      ;;
    --default)
      DEFAULT=YES
      shift # past argument with no value
      ;;
    -*|--*)
      echo "Unknown option $i"
      exit 1
      ;;
    *)
      ;;
  esac
done

echo "FILE EXTENSION  = ${EXTENSION}"
echo "SEARCH PATH     = ${SEARCHPATH}"
echo "DEFAULT         = ${DEFAULT}"
echo "Number files in SEARCH PATH with EXTENSION:" $(ls -1 "${SEARCHPATH}"/*."${EXTENSION}" | wc -l)

if [[ -n $1 ]]; then
    echo "Last line of file specified as non-opt/last argument:"
    tail -1 $1
fi
EOF

chmod +x /tmp/demo-equals-separated.sh

/tmp/demo-equals-separated.sh -e=conf -s=/etc /etc/hosts

复制粘贴上面的块的输出

FILE EXTENSION  = conf
SEARCH PATH     = /etc
DEFAULT         =
Number files in SEARCH PATH with EXTENSION: 14
Last line of file specified as non-opt/last argument:
#93.184.216.34    example.com

用法

demo-equals-separated.sh -e=conf -s=/etc /etc/hosts

要更好地理解${i#*=},请在本指南中搜索“Substring Removal”。它在功能上等同于调用一个不需要的子流程的‘sed’s/[^=]*=//'<<<“$i”`或调用两个不需要子流程的“echo”$i”|sed’s/[^=]*=//'`。


将bash与getopt[s]一起使用

getopt(1)限制(较旧、较新的getopt版本):

无法处理空字符串的参数无法处理带有嵌入空格的参数

最近的getopt版本没有这些限制。有关更多信息,请参阅这些文档。


POSIX获取选项

此外,POSIX外壳和其他提供的getopts没有这些限制。我包含了一个简单的getopts示例。

cat >/tmp/demo-getopts.sh <<'EOF'
#!/bin/sh

# A POSIX variable
OPTIND=1         # Reset in case getopts has been used previously in the shell.

# Initialize our own variables:
output_file=""
verbose=0

while getopts "h?vf:" opt; do
  case "$opt" in
    h|\?)
      show_help
      exit 0
      ;;
    v)  verbose=1
      ;;
    f)  output_file=$OPTARG
      ;;
  esac
done

shift $((OPTIND-1))

[ "${1:-}" = "--" ] && shift

echo "verbose=$verbose, output_file='$output_file', Leftovers: $@"
EOF

chmod +x /tmp/demo-getopts.sh

/tmp/demo-getopts.sh -vf /etc/hosts foo bar

复制粘贴上面的块的输出

verbose=1, output_file='/etc/hosts', Leftovers: foo bar

用法

demo-getopts.sh -vf /etc/hosts foo bar

getopts的优点是:

它更便于携带,可以在其他外壳中使用,如dash。它可以以典型的Unix方式自动处理多个单一选项,如-vf文件名。

getopts的缺点是它只能处理短选项(-h,而不是-help),而无需额外代码。

有一个getopts教程,它解释了所有语法和变量的含义。在bash中,还有帮助getopts,这可能会提供信息。

部署.sh

#!/bin/bash

while [[ "$#" -gt 0 ]]; do
    case $1 in
        -t|--target) target="$2"; shift ;;
        -u|--uglify) uglify=1 ;;
        *) echo "Unknown parameter passed: $1"; exit 1 ;;
    esac
    shift
done

echo "Where to deploy: $target"
echo "Should uglify  : $uglify"

用法:

./deploy.sh -t dev -u

# OR:

./deploy.sh --target dev --uglify