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

此示例显示了如何使用getopt和eval以及HEREDOC和shift来处理短参数和长参数,以及是否具有以下所需值。此外,switch/case语句简洁易懂。

#!/usr/bin/env bash

# usage function
function usage()
{
   cat << HEREDOC

   Usage: $progname [--num NUM] [--time TIME_STR] [--verbose] [--dry-run]

   optional arguments:
     -h, --help           show this help message and exit
     -n, --num NUM        pass in a number
     -t, --time TIME_STR  pass in a time string
     -v, --verbose        increase the verbosity of the bash script
     --dry-run            do a dry run, dont change any files

HEREDOC
}  

# initialize variables
progname=$(basename $0)
verbose=0
dryrun=0
num_str=
time_str=

# use getopt and store the output into $OPTS
# note the use of -o for the short options, --long for the long name options
# and a : for any option that takes a parameter
OPTS=$(getopt -o "hn:t:v" --long "help,num:,time:,verbose,dry-run" -n "$progname" -- "$@")
if [ $? != 0 ] ; then echo "Error in command line arguments." >&2 ; usage; exit 1 ; fi
eval set -- "$OPTS"

while true; do
  # uncomment the next line to see how shift is working
  # echo "\$1:\"$1\" \$2:\"$2\""
  case "$1" in
    -h | --help ) usage; exit; ;;
    -n | --num ) num_str="$2"; shift 2 ;;
    -t | --time ) time_str="$2"; shift 2 ;;
    --dry-run ) dryrun=1; shift ;;
    -v | --verbose ) verbose=$((verbose + 1)); shift ;;
    -- ) shift; break ;;
    * ) break ;;
  esac
done

if (( $verbose > 0 )); then

   # print out all the parameters we read in
   cat <<EOM
   num=$num_str
   time=$time_str
   verbose=$verbose
   dryrun=$dryrun
EOM
fi

# The rest of your script below

以上脚本中最重要的几行是:

OPTS=$(getopt -o "hn:t:v" --long "help,num:,time:,verbose,dry-run" -n "$progname" -- "$@")
if [ $? != 0 ] ; then echo "Error in command line arguments." >&2 ; exit 1 ; fi
eval set -- "$OPTS"

while true; do
  case "$1" in
    -h | --help ) usage; exit; ;;
    -n | --num ) num_str="$2"; shift 2 ;;
    -t | --time ) time_str="$2"; shift 2 ;;
    --dry-run ) dryrun=1; shift ;;
    -v | --verbose ) verbose=$((verbose + 1)); shift ;;
    -- ) shift; break ;;
    * ) break ;;
  esac
done

简短,切中要害,可读,处理几乎所有的事情(IMHO)。

希望这对某人有所帮助。

其他回答

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

无答案展示了增强的getopt。最热门的答案是误导性的:要么忽略-⁠vfd样式的短选项(OP请求)或位置参数后的选项(OP也请求);并且它忽略解析错误。相反:

使用util-linux或以前的GNUglibc.1中的增强getopt它与GNUglibc的C函数getopt_long()一起工作。本页上没有其他解决方案可以做到这一切:在arguments 2中处理空格、引用字符甚至二进制(非增强型getopt无法做到这一点)它可以在结尾处处理选项:script.sh-o outFile file1 file2-v(getopts不执行此操作)allows=-style long选项:script.sh--outfile=fileOut--infile fileIn(如果自解析,则允许两者都很长)允许组合的短选项,例如-vfd(如果是自解析,则实际工作)允许触摸选项参数,例如-oOutfile或-vfdoOutfile它太旧了,以至于没有GNU系统缺少它(例如,任何Linux都有它)。您可以使用:getopt--test测试它的存在→ 返回值4。其他getopt或shell内置getopt用途有限。

以下通话

myscript -vfd ./foo/bar/someFile -o /fizz/someOtherFile
myscript -v -f -d -o/fizz/someOtherFile -- ./foo/bar/someFile
myscript --verbose --force --debug ./foo/bar/someFile -o/fizz/someOtherFile
myscript --output=/fizz/someOtherFile ./foo/bar/someFile -vfd
myscript ./foo/bar/someFile -df -v --output /fizz/someOtherFile

全部返回

verbose: y, force: y, debug: y, in: ./foo/bar/someFile, out: /fizz/someOtherFile

使用以下myscript

#!/bin/bash
# More safety, by turning some bugs into errors.
# Without `errexit` you don’t need ! and can replace
# ${PIPESTATUS[0]} with a simple $?, but I prefer safety.
set -o errexit -o pipefail -o noclobber -o nounset

# -allow a command to fail with !’s side effect on errexit
# -use return value from ${PIPESTATUS[0]}, because ! hosed $?
! getopt --test > /dev/null 
if [[ ${PIPESTATUS[0]} -ne 4 ]]; then
    echo 'I’m sorry, `getopt --test` failed in this environment.'
    exit 1
fi

# option --output/-o requires 1 argument
LONGOPTS=debug,force,output:,verbose
OPTIONS=dfo:v

# -regarding ! and PIPESTATUS see above
# -temporarily store output to be able to check for errors
# -activate quoting/enhanced mode (e.g. by writing out “--options”)
# -pass arguments only via   -- "$@"   to separate them correctly
! PARSED=$(getopt --options=$OPTIONS --longoptions=$LONGOPTS --name "$0" -- "$@")
if [[ ${PIPESTATUS[0]} -ne 0 ]]; then
    # e.g. return value is 1
    #  then getopt has complained about wrong arguments to stdout
    exit 2
fi
# read getopt’s output this way to handle the quoting right:
eval set -- "$PARSED"

d=n f=n v=n outFile=-
# now enjoy the options in order and nicely split until we see --
while true; do
    case "$1" in
        -d|--debug)
            d=y
            shift
            ;;
        -f|--force)
            f=y
            shift
            ;;
        -v|--verbose)
            v=y
            shift
            ;;
        -o|--output)
            outFile="$2"
            shift 2
            ;;
        --)
            shift
            break
            ;;
        *)
            echo "Programming error"
            exit 3
            ;;
    esac
done

# handle non-option arguments
if [[ $# -ne 1 ]]; then
    echo "$0: A single input file is required."
    exit 4
fi

echo "verbose: $v, force: $f, debug: $d, in: $1, out: $outFile"

1增强的getopt可用于大多数“bash系统”,包括Cygwin;在OS X上,尝试brew安装gnu getopt或sudo端口安装getopt2 POSIX exec()约定没有可靠的方法在命令行参数中传递二进制NULL;这些字节过早地结束了参数3 1997年或之前发布的第一个版本(我只追溯到1997年)

使用bash模块中的模块“参数”

例子:

#!/bin/bash
. import.sh log arguments

NAME="world"

parse_arguments "-n|--name)NAME;S" -- "$@" || {
  error "Cannot parse command line."
  exit 1
}

info "Hello, $NAME!"

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。

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