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
保留未处理参数的解决方案。包括演示。
这是我的解决方案。它非常灵活,不像其他软件包,不需要外部包,并且可以干净地处理遗留的参数。
用法为:/myscript-flag flag变量-otherflag flagvar2
您所要做的就是编辑有效标记行。它在前面加上连字符并搜索所有参数。然后它将下一个参数定义为标志名,例如。
./myscript -flag flagvariable -otherflag flagvar2
echo $flag $otherflag
flagvariable flagvar2
主要代码(简短的版本,详细的示例,以及错误输出的版本):
#!/usr/bin/env bash
#shebang.io
validflags="rate time number"
count=1
for arg in $@
do
match=0
argval=$1
for flag in $validflags
do
sflag="-"$flag
if [ "$argval" == "$sflag" ]
then
declare $flag=$2
match=1
fi
done
if [ "$match" == "1" ]
then
shift 2
else
leftovers=$(echo $leftovers $argval)
shift
fi
count=$(($count+1))
done
#Cleanup then restore the leftovers
shift $#
set -- $leftovers
带有内置echo演示的详细版本:
#!/usr/bin/env bash
#shebang.io
rate=30
time=30
number=30
echo "all args
$@"
validflags="rate time number"
count=1
for arg in $@
do
match=0
argval=$1
# argval=$(echo $@ | cut -d ' ' -f$count)
for flag in $validflags
do
sflag="-"$flag
if [ "$argval" == "$sflag" ]
then
declare $flag=$2
match=1
fi
done
if [ "$match" == "1" ]
then
shift 2
else
leftovers=$(echo $leftovers $argval)
shift
fi
count=$(($count+1))
done
#Cleanup then restore the leftovers
echo "pre final clear args:
$@"
shift $#
echo "post final clear args:
$@"
set -- $leftovers
echo "all post set args:
$@"
echo arg1: $1 arg2: $2
echo leftovers: $leftovers
echo rate $rate time $time number $number
最后一个,如果传递了一个无效的参数,这一个会出错。
#!/usr/bin/env bash
#shebang.io
rate=30
time=30
number=30
validflags="rate time number"
count=1
for arg in $@
do
argval=$1
match=0
if [ "${argval:0:1}" == "-" ]
then
for flag in $validflags
do
sflag="-"$flag
if [ "$argval" == "$sflag" ]
then
declare $flag=$2
match=1
fi
done
if [ "$match" == "0" ]
then
echo "Bad argument: $argval"
exit 1
fi
shift 2
else
leftovers=$(echo $leftovers $argval)
shift
fi
count=$(($count+1))
done
#Cleanup then restore the leftovers
shift $#
set -- $leftovers
echo rate $rate time $time number $number
echo leftovers: $leftovers
优点:不管怎么说,它处理得很好。它保留了许多其他解决方案所没有的未使用的参数。它还允许调用变量,而无需在脚本中手动定义。如果没有给出相应的参数,它还允许预填充变量。(请参阅详细示例)。
缺点:无法解析单个复杂的arg字符串,例如-xcvf将作为单个参数处理。不过,您可以很容易地在我的代码中编写额外的代码,以添加此功能。
其他回答
在@brunobronosky的回答基础上,我添加了一个“预处理器”来处理一些常见的格式:
将--longopt=val展开为--longopt-val将-xyz展开为-x-y-z支持--表示标志的结束显示意外选项的错误小巧易读的选项开关
#!/bin/bash
# Report usage
usage() {
echo "Usage:"
echo "$(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[@]}"
根据这里的其他答案,这是我的版本:
#!/bin/bash
set -e
function parse() {
for arg in "$@"; do # transform long options to short ones
shift
case "$arg" in
"--name") set -- "$@" "-n" ;;
"--verbose") set -- "$@" "-v" ;;
*) set -- "$@" "$arg"
esac
done
while getopts "n:v" optname # left to ":" are flags that expect a value, right to the ":" are flags that expect nothing
do
case "$optname" in
"n") name=${OPTARG} ;;
"v") verbose=true ;;
esac
done
shift "$((OPTIND-1))" # shift out all the already processed options
}
parse "$@"
echo "hello $name"
if [ ! -z $verbose ]; then echo 'nice to meet you!'; fi
用法:
$ ./parse.sh
hello
$ ./parse.sh -n YOUR_NAME
hello YOUR_NAME
$ ./parse.sh -n YOUR_NAME -v
hello YOUR_NAME
nice to meet you!
$ ./parse.sh -v -n YOUR_NAME
hello YOUR_NAME
nice to meet you!
$ ./parse.sh -v
hello
nice to meet you!
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=${@}"
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。
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。