我希望使用shell脚本调用长形式和短形式的命令行选项。
我知道可以使用getopts,但是像在Perl中一样,我不能用shell做同样的事情。
关于如何做到这一点的任何想法,这样我就可以使用如下选项:
./shell.sh --copyfile abc.pl /tmp/
./shell.sh -c abc.pl /tmp/
在上面,这两个命令对我的shell意味着同样的事情,但使用getopts,我还不能实现这些?
我希望使用shell脚本调用长形式和短形式的命令行选项。
我知道可以使用getopts,但是像在Perl中一样,我不能用shell做同样的事情。
关于如何做到这一点的任何想法,这样我就可以使用如下选项:
./shell.sh --copyfile abc.pl /tmp/
./shell.sh -c abc.pl /tmp/
在上面,这两个命令对我的shell意味着同样的事情,但使用getopts,我还不能实现这些?
当前回答
长选项可以被内置的标准getopts作为- " option "的"参数"解析。
这是可移植的本地POSIX shell -不需要外部程序或bashisms。
本指南将长选项作为-选项的参数实现,因此——alpha被getopts视为参数alpha为-,而——bravo=foo被参数bravo=foo视为-。true实参通过shell参数展开获取,更新$OPT和$OPTARG。
在本例中,-b和-c(以及它们的长形式——bravo和——charlie)具有强制实参。长选项的参数出现在等号之后,例如——bravo=foo(长选项的空格分隔符很难实现,参见下文)。
因为它使用了内置的getopts,所以这个解决方案支持像cmd——bravo=foo -ac FILE这样的用法(它组合了选项-a和-c,并将长选项与标准选项交织在一起),而这里的大多数其他答案要么很难做到,要么无法做到这一点。
die() { echo "$*" >&2; exit 2; } # complain to STDERR and exit with error
needs_arg() { if [ -z "$OPTARG" ]; then die "No arg for --$OPT option"; fi; }
while getopts ab:c:-: OPT; do
# support long options: https://stackoverflow.com/a/28466267/519360
if [ "$OPT" = "-" ]; then # long option: reformulate OPT and OPTARG
OPT="${OPTARG%%=*}" # extract long option name
OPTARG="${OPTARG#$OPT}" # extract long option argument (may be empty)
OPTARG="${OPTARG#=}" # if long option argument, remove assigning `=`
fi
case "$OPT" in
a | alpha ) alpha=true ;;
b | bravo ) needs_arg; bravo="$OPTARG" ;;
c | charlie ) needs_arg; charlie="$OPTARG" ;;
??* ) die "Illegal option --$OPT" ;; # bad long option
? ) exit 2 ;; # bad short option (error reported via getopts)
esac
done
shift $((OPTIND-1)) # remove parsed options and args from $@ list
When the option is a dash (-), it is a long option. getopts will have parsed the actual long option into $OPTARG, e.g. --bravo=foo originally sets OPT='-' and OPTARG='bravo=foo'. The if stanza sets $OPT to the contents of $OPTARG before the first equals sign (bravo in our example) and then removes that from the beginning of $OPTARG (yielding =foo in this step, or an empty string if there is no =). Finally, we strip the argument's leading =. At this point, $OPT is either a short option (one character) or a long option (2+ characters).
The case then matches either short or long options (the pipe, |, indicates that "or" operation. A long-only option like delta ) delta=true ;; doesn't need a pipe). For short options, getopts automatically complains about options and missing arguments, so we have to replicate those manually using the needs_arg function, which fatally exits when $OPTARG is empty. The ??* condition will match any remaining long option (? matches a single character and * matches zero or more, so ??* matches 2+ characters), allowing us to issue the "Illegal option" error before exiting.
与正常的gnu风格的长选项一样,提供——将停止解析,因此- -- --bravo=4将把$alpha设置为true,但$bravo将保持不变,$1将-bravo=4。我不能说我建议用前导破折号来命名文件,但这是表示它们不是选项的方法。
小错误:如果有人给出了一个无效的单字符长选项(它也不是一个短选项),这将退出一个错误,但没有消息(这个实现假设它是一个短选项)。您可以在case之前的条件中使用一个额外的变量来跟踪它,然后在最后的case条件中测试它,但我认为这是一个太麻烦的角落情况。
大写变量名:一般情况下,建议保留全大写变量供系统使用。我将$OPT保留为全大写,以与$OPTARG保持一致,但这确实打破了这种约定。我认为这很合适,因为这是系统应该做的事情,它应该是安全的;我还没有听说过任何使用这个变量名的标准。
要抱怨长选项的非预期实参:用翻转测试模拟needs_argg来抱怨一个非预期实参:
no_arg() { if [ -n "$OPTARG" ]; then die "No arg allowed for --$OPT option"; fi; }
要接受带空格分隔参数的长选项:您可以用eval "ARG_B=\"\$$OPTIND\""(或使用bash的间接展开,ARG_B="${!OPTIND}")拉入下一个参数,然后增加$OPTIND,正如这个答案的旧版本所指出的那样,但它不可靠;getopts可以过早地终止,假设参数超出了它的作用域,并且一些实现不太适合手动操作$OPTIND。
其他回答
我研究那个课题已经很长时间了。并制作了我自己的库,你将需要在你的主脚本的来源。 有关示例,请参见libopt4shell和cd2mpc。 希望能有所帮助!
下面是一个实际使用长选项的getopt的示例:
aflag=no
bflag=no
cargument=none
# options may be followed by one colon to indicate they have a required argument
if ! options=$(getopt -o abc: -l along,blong,clong: -- "$@")
then
# something went wrong, getopt will put out an error message for us
exit 1
fi
set -- $options
while [ $# -gt 0 ]
do
case $1 in
-a|--along) aflag="yes" ;;
-b|--blong) bflag="yes" ;;
# for options with required arguments, an additional shift is required
-c|--clong) cargument="$2" ; shift;;
(--) shift; break;;
(-*) echo "$0: error - unrecognized option $1" 1>&2; exit 1;;
(*) break;;
esac
shift
done
我想要一个没有外部依赖关系、有严格bash支持(-u)的东西,而且我需要它能在较旧的bash版本上工作。这个函数处理各种类型的参数:
短bool (-h) 短选项(-i "image.jpg") 长boos(——救命) = options(——file="filename.ext") 空格选项(——file "filename.ext") 连接的bool (-hvm)
只需在脚本顶部插入以下内容:
# Check if a list of params contains a specific param
# usage: if _param_variant "h|?|help p|path f|file long-thing t|test-thing" "file" ; then ...
# the global variable $key is updated to the long notation (last entry in the pipe delineated list, if applicable)
_param_variant() {
for param in $1 ; do
local variants=${param//\|/ }
for variant in $variants ; do
if [[ "$variant" = "$2" ]] ; then
# Update the key to match the long version
local arr=(${param//\|/ })
let last=${#arr[@]}-1
key="${arr[$last]}"
return 0
fi
done
done
return 1
}
# Get input parameters in short or long notation, with no dependencies beyond bash
# usage:
# # First, set your defaults
# param_help=false
# param_path="."
# param_file=false
# param_image=false
# param_image_lossy=true
# # Define allowed parameters
# allowed_params="h|?|help p|path f|file i|image image-lossy"
# # Get parameters from the arguments provided
# _get_params $*
#
# Parameters will be converted into safe variable names like:
# param_help,
# param_path,
# param_file,
# param_image,
# param_image_lossy
#
# Parameters without a value like "-h" or "--help" will be treated as
# boolean, and will be set as param_help=true
#
# Parameters can accept values in the various typical ways:
# -i "path/goes/here"
# --image "path/goes/here"
# --image="path/goes/here"
# --image=path/goes/here
# These would all result in effectively the same thing:
# param_image="path/goes/here"
#
# Concatinated short parameters (boolean) are also supported
# -vhm is the same as -v -h -m
_get_params(){
local param_pair
local key
local value
local shift_count
while : ; do
# Ensure we have a valid param. Allows this to work even in -u mode.
if [[ $# == 0 || -z $1 ]] ; then
break
fi
# Split the argument if it contains "="
param_pair=(${1//=/ })
# Remove preceeding dashes
key="${param_pair[0]#--}"
# Check for concatinated boolean short parameters.
local nodash="${key#-}"
local breakout=false
if [[ "$nodash" != "$key" && ${#nodash} -gt 1 ]]; then
# Extrapolate multiple boolean keys in single dash notation. ie. "-vmh" should translate to: "-v -m -h"
local short_param_count=${#nodash}
let new_arg_count=$#+$short_param_count-1
local new_args=""
# $str_pos is the current position in the short param string $nodash
for (( str_pos=0; str_pos<new_arg_count; str_pos++ )); do
# The first character becomes the current key
if [ $str_pos -eq 0 ] ; then
key="${nodash:$str_pos:1}"
breakout=true
fi
# $arg_pos is the current position in the constructed arguments list
let arg_pos=$str_pos+1
if [ $arg_pos -gt $short_param_count ] ; then
# handle other arguments
let orignal_arg_number=$arg_pos-$short_param_count+1
local new_arg="${!orignal_arg_number}"
else
# break out our one argument into new ones
local new_arg="-${nodash:$str_pos:1}"
fi
new_args="$new_args \"$new_arg\""
done
# remove the preceding space and set the new arguments
eval set -- "${new_args# }"
fi
if ! $breakout ; then
key="$nodash"
fi
# By default we expect to shift one argument at a time
shift_count=1
if [ "${#param_pair[@]}" -gt "1" ] ; then
# This is a param with equals notation
value="${param_pair[1]}"
else
# This is either a boolean param and there is no value,
# or the value is the next command line argument
# Assume the value is a boolean true, unless the next argument is found to be a value.
value=true
if [[ $# -gt 1 && -n "$2" ]]; then
local nodash="${2#-}"
if [ "$nodash" = "$2" ]; then
# The next argument has NO preceding dash so it is a value
value="$2"
shift_count=2
fi
fi
fi
# Check that the param being passed is one of the allowed params
if _param_variant "$allowed_params" "$key" ; then
# --key-name will now become param_key_name
eval param_${key//-/_}="$value"
else
printf 'WARNING: Unknown option (ignored): %s\n' "$1" >&2
fi
shift $shift_count
done
}
像这样使用它:
# Assign defaults for parameters
param_help=false
param_path=$(pwd)
param_file=false
param_image=true
param_image_lossy=true
param_image_lossy_quality=85
# Define the params we will allow
allowed_params="h|?|help p|path f|file i|image image-lossy image-lossy-quality"
# Get the params from arguments provided
_get_params $*
发明了另一个版本的轮子……
这个函数(希望)是一个posix兼容的普通bourne shell替换GNU getopt。它支持短/长选项,可以接受强制/可选/无参数,并且指定选项的方式几乎与GNU getopt相同,因此转换是微不足道的。
当然,要放入脚本中,这仍然是相当大的代码块,但它大约是众所周知的getopt_long shell函数的一半行数,并且在您只想替换现有的GNU getopt使用的情况下可能更可取。
这是相当新的代码,所以是YMMV(如果因为某种原因它实际上与POSIX不兼容,请务必告诉我——可移植性是一开始的意图,但我没有一个有用的POSIX测试环境)。
代码和示例用法如下:
#!/bin/sh
# posix_getopt shell function
# Author: Phil S.
# Version: 1.0
# Created: 2016-07-05
# URL: http://stackoverflow.com/a/37087374/324105
# POSIX-compatible argument quoting and parameter save/restore
# http://www.etalabs.net/sh_tricks.html
# Usage:
# parameters=$(save "$@") # save the original parameters.
# eval "set -- ${parameters}" # restore the saved parameters.
save () {
local param
for param; do
printf %s\\n "$param" \
| sed "s/'/'\\\\''/g;1s/^/'/;\$s/\$/' \\\\/"
done
printf %s\\n " "
}
# Exit with status $1 after displaying error message $2.
exiterr () {
printf %s\\n "$2" >&2
exit $1
}
# POSIX-compatible command line option parsing.
# This function supports long options and optional arguments, and is
# a (largely-compatible) drop-in replacement for GNU getopt.
#
# Instead of:
# opts=$(getopt -o "$shortopts" -l "$longopts" -- "$@")
# eval set -- ${opts}
#
# We instead use:
# opts=$(posix_getopt "$shortopts" "$longopts" "$@")
# eval "set -- ${opts}"
posix_getopt () { # args: "$shortopts" "$longopts" "$@"
local shortopts longopts \
arg argtype getopt nonopt opt optchar optword suffix
shortopts="$1"
longopts="$2"
shift 2
getopt=
nonopt=
while [ $# -gt 0 ]; do
opt=
arg=
argtype=
case "$1" in
# '--' means don't parse the remaining options
( -- ) {
getopt="${getopt}$(save "$@")"
shift $#
break
};;
# process short option
( -[!-]* ) { # -x[foo]
suffix=${1#-?} # foo
opt=${1%$suffix} # -x
optchar=${opt#-} # x
case "${shortopts}" in
( *${optchar}::* ) { # optional argument
argtype=optional
arg="${suffix}"
shift
};;
( *${optchar}:* ) { # required argument
argtype=required
if [ -n "${suffix}" ]; then
arg="${suffix}"
shift
else
case "$2" in
( -* ) exiterr 1 "$1 requires an argument";;
( ?* ) arg="$2"; shift 2;;
( * ) exiterr 1 "$1 requires an argument";;
esac
fi
};;
( *${optchar}* ) { # no argument
argtype=none
arg=
shift
# Handle multiple no-argument parameters combined as
# -xyz instead of -x -y -z. If we have just shifted
# parameter -xyz, we now replace it with -yz (which
# will be processed in the next iteration).
if [ -n "${suffix}" ]; then
eval "set -- $(save "-${suffix}")$(save "$@")"
fi
};;
( * ) exiterr 1 "Unknown option $1";;
esac
};;
# process long option
( --?* ) { # --xarg[=foo]
suffix=${1#*=} # foo (unless there was no =)
if [ "${suffix}" = "$1" ]; then
suffix=
fi
opt=${1%=$suffix} # --xarg
optword=${opt#--} # xarg
case ",${longopts}," in
( *,${optword}::,* ) { # optional argument
argtype=optional
arg="${suffix}"
shift
};;
( *,${optword}:,* ) { # required argument
argtype=required
if [ -n "${suffix}" ]; then
arg="${suffix}"
shift
else
case "$2" in
( -* ) exiterr 1 \
"--${optword} requires an argument";;
( ?* ) arg="$2"; shift 2;;
( * ) exiterr 1 \
"--${optword} requires an argument";;
esac
fi
};;
( *,${optword},* ) { # no argument
if [ -n "${suffix}" ]; then
exiterr 1 "--${optword} does not take an argument"
fi
argtype=none
arg=
shift
};;
( * ) exiterr 1 "Unknown option $1";;
esac
};;
# any other parameters starting with -
( -* ) exiterr 1 "Unknown option $1";;
# remember non-option parameters
( * ) nonopt="${nonopt}$(save "$1")"; shift;;
esac
if [ -n "${opt}" ]; then
getopt="${getopt}$(save "$opt")"
case "${argtype}" in
( optional|required ) {
getopt="${getopt}$(save "$arg")"
};;
esac
fi
done
# Generate function output, suitable for:
# eval "set -- $(posix_getopt ...)"
printf %s "${getopt}"
if [ -n "${nonopt}" ]; then
printf %s "$(save "--")${nonopt}"
fi
}
使用示例:
# Process command line options
shortopts="hvd:c::s::L:D"
longopts="help,version,directory:,client::,server::,load:,delete"
#opts=$(getopt -o "$shortopts" -l "$longopts" -n "$(basename $0)" -- "$@")
opts=$(posix_getopt "$shortopts" "$longopts" "$@")
if [ $? -eq 0 ]; then
#eval set -- ${opts}
eval "set -- ${opts}"
while [ $# -gt 0 ]; do
case "$1" in
( -- ) shift; break;;
( -h|--help ) help=1; shift; break;;
( -v|--version ) version_help=1; shift; break;;
( -d|--directory ) dir=$2; shift 2;;
( -c|--client ) useclient=1; client=$2; shift 2;;
( -s|--server ) startserver=1; server_name=$2; shift 2;;
( -L|--load ) load=$2; shift 2;;
( -D|--delete ) delete=1; shift;;
esac
done
else
shorthelp=1 # getopt returned (and reported) an error.
fi
公认的答案很好地指出了bash内置getopts的所有缺点。答案以:
因此,虽然可以编写更多的代码来解决长选项支持不足的问题,但工作量要大得多,并且在一定程度上违背了使用getopt解析器来简化代码的目的。
尽管我原则上同意这种说法,但我觉得我们在各种脚本中实现这个特性的次数证明,我们应该花一些精力来创建一个“标准化”的、经过良好测试的解决方案。
因此,我通过在纯bash中实现getopts_long“升级”了内置在getopts中的bash,没有外部依赖。该函数的使用与内置的getopts 100%兼容。
通过在脚本中包含getopts_long(在GitHub上托管),可以简单地实现原始问题的答案:
source "${PATH_TO}/getopts_long.bash"
while getopts_long ':c: copyfile:' OPTKEY; do
case ${OPTKEY} in
'c'|'copyfile')
echo 'file supplied -- ${OPTARG}'
;;
'?')
echo "INVALID OPTION -- ${OPTARG}" >&2
exit 1
;;
':')
echo "MISSING ARGUMENT for option -- ${OPTARG}" >&2
exit 1
;;
*)
echo "Misconfigured OPTSPEC or uncaught option -- ${OPTKEY}" >&2
exit 1
;;
esac
done
shift $(( OPTIND - 1 ))
[[ "${1}" == "--" ]] && shift