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
另一个Shell参数分析器(ASAP)
符合POSIX,无getopt
我受到@bronson相对简单的回答的启发,并试图改进它(不增加太多复杂性)。结果如下:
使用-n[arg]、-abn[arg],--name[arg]和--name=arg样式中的任意一种选项;参数可以按任何顺序出现,循环后$@中只留下位置参数;使用--强制将剩余的参数视为位置参数;检测无效选项和缺少的参数;不依赖于getopt或外部工具(一个功能使用简单的sed命令);便携式,紧凑,可读性强,具有独立功能。
# Convenience functions.
usage_error () { echo >&2 "$(basename $0): $1"; exit 2; }
assert_argument () { test "$1" != "$EOL" || usage_error "$2 requires an argument"; }
# One loop, nothing more.
if [ "$#" != 0 ]; then
EOL=$(printf '\1\3\3\7')
set -- "$@" "$EOL"
while [ "$1" != "$EOL" ]; do
opt="$1"; shift
case "$opt" in
# Your options go here.
-f|--flag) flag='true';;
-n|--name) assert_argument "$1" "$opt"; name="$1"; shift;;
# Arguments processing. You may remove any unneeded line after the 1st.
-|''|[!-]*) set -- "$@" "$opt";; # positional argument, rotate to the end
--*=*) set -- "${opt%%=*}" "${opt#*=}" "$@";; # convert '--name=arg' to '--name' 'arg'
-[!-]?*) set -- $(echo "${opt#-}" | sed 's/\(.\)/ -\1/g') "$@";; # convert '-abc' to '-a' '-b' '-c'
--) while [ "$1" != "$EOL" ]; do set -- "$@" "$1"; shift; done;; # process remaining arguments as positional
-*) usage_error "unknown option: '$opt'";; # catch misspelled options
*) usage_error "this should NEVER happen ($opt)";; # sanity test for previous patterns
esac
done
shift # $EOL
fi
# Do something cool with "$@"... \o/
注:我知道。。。二进制模式为0x01030307的参数可能会破坏逻辑。但是,如果有人在命令行中传递这样的参数,他们应该得到它。
其他回答
来自digitalpeer.com,稍作修改:
用法myscript.sh-p=my_prefix-s=dirname-l=libname
#!/bin/bash
for i in "$@"
do
case $i in
-p=*|--prefix=*)
PREFIX="${i#*=}"
;;
-s=*|--searchpath=*)
SEARCHPATH="${i#*=}"
;;
-l=*|--lib=*)
DIR="${i#*=}"
;;
--default)
DEFAULT=YES
;;
*)
# unknown option
;;
esac
done
echo PREFIX = ${PREFIX}
echo SEARCH PATH = ${SEARCHPATH}
echo DIRS = ${DIR}
echo DEFAULT = ${DEFAULT}
要更好地理解${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/[^=]*=//'`。
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: $@"
EOF
chmod +x /tmp/demo-getopts.sh
/tmp/demo-getopts.sh -vf /etc/hosts foo bar
复制粘贴上面的块的输出
verbose=1, output_file='/etc/hosts', Leftovers: foo bar
用法
demo-getopts.sh -vf /etc/hosts foo bar
getopts的优点是:
它更便于携带,可以在其他外壳中使用,如dash。它可以以典型的Unix方式自动处理多个单一选项,如-vf文件名。
getopts的缺点是它只能处理短选项(-h,而不是-help),而无需额外代码。
有一个getopts教程,它解释了所有语法和变量的含义。在bash中,还有帮助getopts,这可能会提供信息。
有几种方法可以解析cmdline参数(例如GNU getopt(不可移植)vs BSD(MacOS)getopt vs getopts)-所有这些都有问题。此解决方案
是便携式的!没有依赖关系,仅依赖于bash内置允许短期和长期选项处理空格或同时在选项和参数之间使用=分隔符支持串联短选项样式-vxfhandles选项和可选参数(例如--color vs--color=always),正确检测和报告未知选项支持--表示选项结束,以及与相同功能集的替代方案相比,不需要代码膨胀。即简洁,因此易于维护
示例:任何
# flag
-f
--foo
# option with required argument
-b"Hello World"
-b "Hello World"
--bar "Hello World"
--bar="Hello World"
# option with optional argument
--baz
--baz="Optional Hello"
#!/usr/bin/env bash
usage() {
cat - >&2 <<EOF
NAME
program-name.sh - Brief description
SYNOPSIS
program-name.sh [-h|--help]
program-name.sh [-f|--foo]
[-b|--bar <arg>]
[--baz[=<arg>]]
[--]
FILE ...
REQUIRED ARGUMENTS
FILE ...
input files
OPTIONS
-h, --help
Prints this and exits
-f, --foo
A flag option
-b, --bar <arg>
Option requiring an argument <arg>
--baz[=<arg>]
Option that has an optional argument <arg>. If <arg>
is not specified, defaults to 'DEFAULT'
--
Specify end of options; useful if the first non option
argument starts with a hyphen
EOF
}
fatal() {
for i; do
echo -e "${i}" >&2
done
exit 1
}
# For long option processing
next_arg() {
if [[ $OPTARG == *=* ]]; then
# for cases like '--opt=arg'
OPTARG="${OPTARG#*=}"
else
# for cases like '--opt arg'
OPTARG="${args[$OPTIND]}"
OPTIND=$((OPTIND + 1))
fi
}
# ':' means preceding option character expects one argument, except
# first ':' which make getopts run in silent mode. We handle errors with
# wildcard case catch. Long options are considered as the '-' character
optspec=":hfb:-:"
args=("" "$@") # dummy first element so $1 and $args[1] are aligned
while getopts "$optspec" optchar; do
case "$optchar" in
h) usage; exit 0 ;;
f) foo=1 ;;
b) bar="$OPTARG" ;;
-) # long option processing
case "$OPTARG" in
help)
usage; exit 0 ;;
foo)
foo=1 ;;
bar|bar=*) next_arg
bar="$OPTARG" ;;
baz)
baz=DEFAULT ;;
baz=*) next_arg
baz="$OPTARG" ;;
-) break ;;
*) fatal "Unknown option '--${OPTARG}'" "see '${0} --help' for usage" ;;
esac
;;
*) fatal "Unknown option: '-${OPTARG}'" "See '${0} --help' for usage" ;;
esac
done
shift $((OPTIND-1))
if [ "$#" -eq 0 ]; then
fatal "Expected at least one required argument FILE" \
"See '${0} --help' for usage"
fi
echo "foo=$foo, bar=$bar, baz=$baz, files=${@}"
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