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
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 $*
其他回答
下面是一个实际使用长选项的getopt的示例:
aflag=no
bflag=no
cargument=none
# options may be followed by one colon to indicate they have a required argument
if ! options=$(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 $1" 1>&2; exit 1;;
(*) break;;
esac
shift
done
可以考虑以下三种实现方式:
Bash内置的getopts。这不支持带有双破折号前缀的长选项名。它只支持单字符选项。 BSD UNIX实现的独立getopt命令(这是MacOS使用的)。这也不支持长选项。 独立getopt的GNU实现。GNU getopt(3)(由Linux上的命令行getopt(1)使用)支持解析长选项。
其他一些答案给出了使用bash内置getopts模拟长选项的解决方案。该解决方案实际上生成了一个字符为“-”的短选项。所以你得到“——”作为标志。然后,后面的所有内容都变成OPTARG,并使用嵌套的case测试OPTARG。
这很聪明,但也需要注意:
getopts不能强制执行opt规范。如果用户提供了无效的选项,它不能返回错误。在解析OPTARG时,您必须自己进行错误检查。 OPTARG用于长选项名称,当长选项本身有参数时,这会使使用复杂化。你最终不得不自己编写代码作为一个额外的案例。
因此,虽然可以编写更多的代码来解决长选项支持不足的问题,但工作量要大得多,并且在一定程度上违背了使用getopt解析器来简化代码的目的。
内置的getopts不能做到这一点。有一个外部的getopt(1)程序可以做到这一点,但是您只能在Linux上从util-linux包中获得它。它附带一个示例脚本getop -parse.bash。
还有一个getopts_long被写成shell函数。
例如,如果所有长选项都有唯一且匹配的首字符作为短选项
./slamm --chaos 23 --plenty test -quiet
和
./slamm -c 23 -p test -q
你可以在getopts重写$args之前使用它:
# change long options to short options
for arg; do
[[ "${arg:0:1}" == "-" ]] && delim="" || delim="\""
if [ "${arg:0:2}" == "--" ];
then args="${args} -${arg:2:1}"
else args="${args} ${delim}${arg}${delim}"
fi
done
# reset the incoming args
eval set -- $args
# proceed as usual
while getopts ":b:la:h" OPTION; do
.....
谢谢mtvee的灵感;-)
对于getopts部分,如果需要较长的命令行选项,使用ksh可能更简单,因为在ksh中更容易完成。
# Working Getopts Long => KSH
#! /bin/ksh
# Getopts Long
USAGE="s(showconfig)"
USAGE+="c:(createdb)"
USAGE+="l:(createlistener)"
USAGE+="g:(generatescripts)"
USAGE+="r:(removedb)"
USAGE+="x:(removelistener)"
USAGE+="t:(createtemplate)"
USAGE+="h(help)"
while getopts "$USAGE" optchar ; do
case $optchar in
s) echo "Displaying Configuration" ;;
c) echo "Creating Database $OPTARG" ;;
l) echo "Creating Listener LISTENER_$OPTARG" ;;
g) echo "Generating Scripts for Database $OPTARG" ;;
r) echo "Removing Database $OPTARG" ;;
x) echo "Removing Listener LISTENER_$OPTARG" ;;
t) echo "Creating Database Template" ;;
h) echo "Help" ;;
esac
done