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

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

其他回答

在@brunobronosky的回答基础上,我添加了一个“预处理器”来处理一些常见的格式:

将--longopt=val展开为--longopt-val将-xyz展开为-x-y-z支持--表示标志的结束显示意外选项的错误小巧易读的选项开关

#!/bin/bash

# Report usage
usage() {
  echo "Usage:"
  echo "$(basename "$0") [options] [--] [file1, ...]"
}

invalid() {
  echo "ERROR: Unrecognized argument: $1" >&2
  usage
  exit 1
}

# Pre-process options to:
# - expand -xyz into -x -y -z
# - expand --longopt=arg into --longopt arg
ARGV=()
END_OF_OPT=
while [[ $# -gt 0 ]]; do
  arg="$1"; shift
  case "${END_OF_OPT}${arg}" in
    --) ARGV+=("$arg"); END_OF_OPT=1 ;;
    --*=*)ARGV+=("${arg%%=*}" "${arg#*=}") ;;
    --*) ARGV+=("$arg") ;;
    -*) for i in $(seq 2 ${#arg}); do ARGV+=("-${arg:i-1:1}"); done ;;
    *) ARGV+=("$arg") ;;
  esac
done

# Apply pre-processed options
set -- "${ARGV[@]}"

# Parse options
END_OF_OPT=
POSITIONAL=()
while [[ $# -gt 0 ]]; do
  case "${END_OF_OPT}${1}" in
    -h|--help)      usage; exit 0 ;;
    -p|--password)  shift; PASSWORD="$1" ;;
    -u|--username)  shift; USERNAME="$1" ;;
    -n|--name)      shift; names+=("$1") ;;
    -q|--quiet)     QUIET=1 ;;
    -C|--copy)      COPY=1 ;;
    -N|--notify)    NOTIFY=1 ;;
    --stdin)        READ_STDIN=1 ;;
    --)             END_OF_OPT=1 ;;
    -*)             invalid "$1" ;;
    *)              POSITIONAL+=("$1") ;;
  esac
  shift
done

# Restore positional parameters
set -- "${POSITIONAL[@]}"

如果您正在制作可与其他实用程序互换的脚本,下面的灵活性可能很有用。

以下任一项:

command -x=myfilename.ext --another_switch 

Or:

command -x myfilename.ext --another_switch

代码如下:

STD_IN=0

prefix=""
key=""
value=""
for keyValue in "$@"
do
  case "${prefix}${keyValue}" in
    -i=*|--input_filename=*)  key="-i";     value="${keyValue#*=}";; 
    -ss=*|--seek_from=*)      key="-ss";    value="${keyValue#*=}";;
    -t=*|--play_seconds=*)    key="-t";     value="${keyValue#*=}";;
    -|--stdin)                key="-";      value=1;;
    *)                                      value=$keyValue;;
  esac
  case $key in
    -i) MOVIE=$(resolveMovie "${value}");  prefix=""; key="";;
    -ss) SEEK_FROM="${value}";          prefix=""; key="";;
    -t)  PLAY_SECONDS="${value}";           prefix=""; key="";;
    -)   STD_IN=${value};                   prefix=""; key="";; 
    *)   prefix="${keyValue}=";;
  esac
done

我最终实现了公认答案的dash(或/bin/sh)版本,基本上不使用数组:

while [[ $# -gt 0 ]]; do
    case "$1" in
    -v|--verbose) verbose=1; shift;;
    -o|--output) if [[ $# -gt 1 && "$2" != -* ]]; then
            file=$2; shift 2
        else
            echo "-o requires file-path" 1>&2; exit 1
        fi ;;
    --)
        while [[ $# -gt 0 ]]; do BACKUP="$BACKUP;$1"; shift; done
        break;;
    *)
        BACKUP="$BACKUP;$1"
        shift
        ;;
    esac
done
# Restore unused arguments.
while [ -n "$BACKUP" ] ; do
    [ ! -z "${BACKUP%%;*}" ] && set -- "$@" "${BACKUP%%;*}"
    [ "$BACKUP" = "${BACKUP/;/}" ] && break
    BACKUP="${BACKUP#*;}"
done

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。

这是我在函数中如何避免在堆栈的较高位置同时中断getopts运行:

function waitForWeb () {
   local OPTIND=1 OPTARG OPTION
   local host=localhost port=8080 proto=http
   while getopts "h:p:r:" OPTION; do
      case "$OPTION" in
      h)
         host="$OPTARG"
         ;;
      p)
         port="$OPTARG"
         ;;
      r)
         proto="$OPTARG"
         ;;
      esac
   done
...
}