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?
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
我想提供我的选项解析版本,它允许以下内容:
-s p1
--stage p1
-w somefolder
--workfolder somefolder
-sw p1 somefolder
-e=hello
也允许这样做(可能不需要):
-s--workfolder p1 somefolder
-se=hello p1
-swe=hello p1 somefolder
您必须在使用前决定是否在选项上使用=。这是为了保持代码干净。
while [[ $# > 0 ]]
do
key="$1"
while [[ ${key+x} ]]
do
case $key in
-s*|--stage)
STAGE="$2"
shift # option has parameter
;;
-w*|--workfolder)
workfolder="$2"
shift # option has parameter
;;
-e=*)
EXAMPLE="${key#*=}"
break # option has been fully handled
;;
*)
# unknown option
echo Unknown option: $key #1>&2
exit 10 # either this: my preferred way to handle unknown options
break # or this: do this to signal the option has been handled (if exit isn't used)
;;
esac
# prepare for next option in this key, if any
[[ "$key" = -? || "$key" == --* ]] && unset key || key="${key/#-?/-}"
done
shift # option(s) fully processed, proceed to next input argument
done
其他回答
我给你一个函数parse_params,它将从命令行解析参数。
这是一个纯Bash解决方案,没有额外的实用程序。不会污染全球范围。轻松地返回简单易用的变量,您可以在这些变量上构建进一步的逻辑。params前面的破折号数量无关紧要(--all等于-all等于all=all)
下面的脚本是复制粘贴工作演示。请参见show_use函数以了解如何使用parse_param。
限制:
不支持空格分隔的参数(-d 1)参数名称将丢失破折号,因此--any参数和-anyparam等效eval$(parse_params“$@”)必须在bash函数中使用(它在全局范围内不起作用)
#!/bin/bash
# Universal Bash parameter parsing
# Parse equal sign separated params into named local variables
# Standalone named parameter value will equal its param name (--force creates variable $force=="force")
# Parses multi-valued named params into an array (--path=path1 --path=path2 creates ${path[*]} array)
# Puts un-named params as-is into ${ARGV[*]} array
# Additionally puts all named params as-is into ${ARGN[*]} array
# Additionally puts all standalone "option" params as-is into ${ARGO[*]} array
# @author Oleksii Chekulaiev
# @version v1.4.1 (Jul-27-2018)
parse_params ()
{
local existing_named
local ARGV=() # un-named params
local ARGN=() # named params
local ARGO=() # options (--params)
echo "local ARGV=(); local ARGN=(); local ARGO=();"
while [[ "$1" != "" ]]; do
# Escape asterisk to prevent bash asterisk expansion, and quotes to prevent string breakage
_escaped=${1/\*/\'\"*\"\'}
_escaped=${_escaped//\'/\\\'}
_escaped=${_escaped//\"/\\\"}
# If equals delimited named parameter
nonspace="[^[:space:]]"
if [[ "$1" =~ ^${nonspace}${nonspace}*=..* ]]; then
# Add to named parameters array
echo "ARGN+=('$_escaped');"
# key is part before first =
local _key=$(echo "$1" | cut -d = -f 1)
# Just add as non-named when key is empty or contains space
if [[ "$_key" == "" || "$_key" =~ " " ]]; then
echo "ARGV+=('$_escaped');"
shift
continue
fi
# val is everything after key and = (protect from param==value error)
local _val="${1/$_key=}"
# remove dashes from key name
_key=${_key//\-}
# skip when key is empty
# search for existing parameter name
if (echo "$existing_named" | grep "\b$_key\b" >/dev/null); then
# if name already exists then it's a multi-value named parameter
# re-declare it as an array if needed
if ! (declare -p _key 2> /dev/null | grep -q 'declare \-a'); then
echo "$_key=(\"\$$_key\");"
fi
# append new value
echo "$_key+=('$_val');"
else
# single-value named parameter
echo "local $_key='$_val';"
existing_named=" $_key"
fi
# If standalone named parameter
elif [[ "$1" =~ ^\-${nonspace}+ ]]; then
# remove dashes
local _key=${1//\-}
# Just add as non-named when key is empty or contains space
if [[ "$_key" == "" || "$_key" =~ " " ]]; then
echo "ARGV+=('$_escaped');"
shift
continue
fi
# Add to options array
echo "ARGO+=('$_escaped');"
echo "local $_key=\"$_key\";"
# non-named parameter
else
# Escape asterisk to prevent bash asterisk expansion
_escaped=${1/\*/\'\"*\"\'}
echo "ARGV+=('$_escaped');"
fi
shift
done
}
#--------------------------- DEMO OF THE USAGE -------------------------------
show_use ()
{
eval $(parse_params "$@")
# --
echo "${ARGV[0]}" # print first unnamed param
echo "${ARGV[1]}" # print second unnamed param
echo "${ARGN[0]}" # print first named param
echo "${ARG0[0]}" # print first option param (--force)
echo "$anyparam" # print --anyparam value
echo "$k" # print k=5 value
echo "${multivalue[0]}" # print first value of multi-value
echo "${multivalue[1]}" # print second value of multi-value
[[ "$force" == "force" ]] && echo "\$force is set so let the force be with you"
}
show_use "param 1" --anyparam="my value" param2 k=5 --force --multi-value=test1 --multi-value=test2
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: $@"
EOF
chmod +x /tmp/demo-getopts.sh
/tmp/demo-getopts.sh -vf /etc/hosts foo bar
复制粘贴上面的块的输出
verbose=1, output_file='/etc/hosts', Leftovers: foo bar
用法
demo-getopts.sh -vf /etc/hosts foo bar
getopts的优点是:
它更便于携带,可以在其他外壳中使用,如dash。它可以以典型的Unix方式自动处理多个单一选项,如-vf文件名。
getopts的缺点是它只能处理短选项(-h,而不是-help),而无需额外代码。
有一个getopts教程,它解释了所有语法和变量的含义。在bash中,还有帮助getopts,这可能会提供信息。
getopts非常有用,如果您首先安装了它,然后您打算在同一平台上运行它。例如,OSX和Linux在这方面的表现不同。
这里有一个(非getopts)解决方案,它支持等于、非等于和布尔标志。例如,您可以通过以下方式运行脚本:
./script --arg1=value1 --arg2 value2 --shouldClean
# parse the arguments.
COUNTER=0
ARGS=("$@")
while [ $COUNTER -lt $# ]
do
arg=${ARGS[$COUNTER]}
let COUNTER=COUNTER+1
nextArg=${ARGS[$COUNTER]}
if [[ $skipNext -eq 1 ]]; then
echo "Skipping"
skipNext=0
continue
fi
argKey=""
argVal=""
if [[ "$arg" =~ ^\- ]]; then
# if the format is: -key=value
if [[ "$arg" =~ \= ]]; then
argVal=$(echo "$arg" | cut -d'=' -f2)
argKey=$(echo "$arg" | cut -d'=' -f1)
skipNext=0
# if the format is: -key value
elif [[ ! "$nextArg" =~ ^\- ]]; then
argKey="$arg"
argVal="$nextArg"
skipNext=1
# if the format is: -key (a boolean flag)
elif [[ "$nextArg" =~ ^\- ]] || [[ -z "$nextArg" ]]; then
argKey="$arg"
argVal=""
skipNext=0
fi
# if the format has not flag, just a value.
else
argKey=""
argVal="$arg"
skipNext=0
fi
case "$argKey" in
--source-scmurl)
SOURCE_URL="$argVal"
;;
--dest-scmurl)
DEST_URL="$argVal"
;;
--version-num)
VERSION_NUM="$argVal"
;;
-c|--clean)
CLEAN_BEFORE_START="1"
;;
-h|--help|-help|--h)
showUsage
exit
;;
esac
done
我发现在脚本中编写可移植解析的问题非常令人沮丧,因此我编写了Argbash-一个FOSS代码生成器,它可以为您的脚本生成参数解析代码,并且具有一些不错的功能:
https://argbash.io
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
...
}