jehiah/simple_args_parsing.sh

stancufm · 2017-05-12T16:58:49Z

I've started the run-sections project if you need more than just parsing arguments. With run-sections you can chose what part of you code do you want to run and much more. You can simply mark sections inside your script and run just that sections. If you are interested on this idea, please have a look on https://github.com/stancufm/run-sections . It's very easy to work with this function.

tchalvak · 2017-06-29T21:12:56Z

./simple_args_parsing.sh
./simple_args_parsing.sh: 13: ./simple_args_parsing.sh: Syntax error: "(" unexpected

Soo... not great.

gperreymond · 2017-09-28T13:54:55Z

Hotfix this

function usage()
{

With :

usage() {

migaes · 2018-04-09T16:26:05Z

Nice gist conception!
Just a small detail, add -e to echo commands in the help menu, so it will format special tab characters ...

justme-justus · 2018-05-31T08:26:07Z

echo "\t-h --help"

shouldn't it be echo -e? Otherwise it prints \t in my case.

Or better use printf?

elliotboney · 2018-07-17T17:53:28Z

@geoff-codes thanks for the snippet! @hypersoft's solution was hella less readable

LeeYunhang · 2018-09-11T09:23:35Z

Thank you a lot

LeeYunhang · 2018-09-11T09:24:43Z

@gperreymond is right, without function keyword is better than with it.

BatmanAoD · 2019-01-08T22:28:21Z

@hypersoft 👎 You've complicated a really simple task.

kthoms · 2019-01-22T10:54:25Z

Thanks, works fine. Use echo -e "\t-h --help" as @bestjejust suggested for printing out tab.

Yann-Situ · 2019-06-27T08:08:44Z

I have difficulties for parsing "-e" with that, I think it interferes with the 'echo $1 line 25.

Pagliacii · 2020-04-10T08:39:31Z

This works fine with or without an equal symbol.

while [ "$1" != "" ]; do
    PARAM=`printf "%s\n" $1 | awk -F= '{print $1}'`
    VALUE=`printf "%s\n" $1 | sed 's/^[^=]*=//g'`
    if [[ $VALUE == $PARAM ]]; then
        shift
        VALUE=$1
    fi
    ...
done

Ivancaminal72 · 2020-04-27T12:34:33Z

@perepechaev An even better way would be

awk -F= '{OFS="=";$1=""; printf substr($0,2)}'

In case that $VALUE is not provided returns an empty string

cslycord · 2020-04-30T11:14:08Z

@Pagliacii

This works fine with or without an equal symbol.

while [ "$1" != "" ]; do
    PARAM=`printf "%s\n" $1 | awk -F= '{print $1}'`
    VALUE=`printf "%s\n" $1 | sed 's/^[^=]*=//g'`
    if [[ $VALUE == $PARAM ]]; then
        shift
        VALUE=$1
    fi
    ...
done

If you change if [[ $VALUE == $PARAM ]]" to if [ "$VALUE" = "$PARAM" ] it will be more portable.
The code in the OP was written to be run as /bin/sh, so the [[ ]] and == parts could be a problem since they're not POSIX.

Also, I think it's better to change PARAM=printf "%s\n" $1 | awk -F= '{print $1}' to PARAM="$(printf "%s\n" $1 | awk -F= '{print $1}')"
and VALUE=printf "%s\n" $1 | sed 's/^[^=]*=//g' to VALUE="$(printf "%s\n" $1 | sed 's/^[^=]*=//g')"

unfor19 · 2020-07-23T13:54:53Z

I wrote this - https://github.com/unfor19/bargs - exactly for this need, so you don't need to write down while case esac shift thingy, a very simple and flexible implementation

ko1nksm · 2020-11-08T12:11:48Z

I wrote another optional parser and generator that POSIX-compliant and works with all POSIX shells (e.g. dash, bash 2.0+, ksh88, zsh 3.1+, busybox ash). It is a pure shell function and aims to be compatible with POSIX and GNU option syntax. Its code is as fast and small as possible, and the CC0 license allows you to embed it freely in your scripts. https://github.com/ko1nksm/getoptions

2020-11-19: Add support for abbreviated long options and subcommands.

alanmur · 2021-11-08T22:31:24Z

I used the work of @hypersoft for my own script and made some bug fixes and improvements to meet my needs. Giving back the results, which I have simplified for the sake of clarity.

#!/bin/bash

DIRNAME=$(dirname -- $0)
BASENAME=$(basename -- $0)

usage()
{
    echo "USAGE: $BASENAME [OPTIONS]"
    echo
    echo "OPTIONS"
    echo "  -r, --require-approval   Ask user for security approval when deploying CDK stacks"
    echo
    echo "  Features deployed will be the sum \(union\) of the following options, if none"
    echo "  is specified then all features will be deployed by default. \(Specify each"
    echo "  option separately, as a group like -yld will not be understood\)"
    echo "  -a, --all                Deploy all features"
    echo "  -y, --analytics          Deploy the analytics features"
    echo
    echo "  -v, --verbose [level]    Output additional info. (can use -v=2 form also)"
    echo "                           Possible levels:"
    echo "                               0 \(default\)    essential info"
    echo "                               1              more info"
    echo "                               2              even more info"
    echo
    echo "POSITIONAL PARAMETERS"
    echo "  none"
    exit
}

# default values for flags. always use 1 for true and 0 for false. use strings for qualifiers.
REQUIREAPPROVAL="--require-approval never"
DEFAULT=1
ALL=0
ANALYTICS=0
VERBOSELEVEL="0"

while [[ $# > 0 ]]
do
    echo num $#
    [[ $1 =~ ^-h$|^--help$ ]] && {
        usage
    };
    # -- marks end of options and start of positional parameters
    [[ $1 == -- ]] && { shift; break; };

    # options without parameters
    [[ $1 =~ ^-r$|^--require-approval$ ]] && { REQUIREAPPROVAL=; shift 1; continue; };
    [[ $1 =~ ^-a$|^--all$ ]] && { ALL=1; DEFAULT=0; shift 1; continue; };
    [[ $1 =~ ^-y$|^--analytics$ ]] && { ANALYTICS=1; DEFAULT=0; shift 1; continue; };

    # verbose option with optional value. e.g. -v, -v 0, -v 1, --verbose, --verbose 1
    [[ $1 =~ ^-v$|^--verbose$ ]] && {
        shift 1
        [[ $# == 0 ]] && { continue; };
        VERBOSELEVEL="$1"
    };

    # verbose option with = value. e.g. -v=0, -v=1, -v=2, --verbose=1 etc.
    [[ $1 =~ ^-v=|^--verbose= ]] && {
        VERBOSELEVEL="${1#*=}"
        shift 1
        continue;
    };

    break;
done

# validate string parameters
[[ ! $VERBOSELEVEL =~ ^[0-2]$ ]] && {
    echo illegal --verbose parameter $VERBOSELEVEL
    usage
};

# if verbose 1 or 2
[[ ! $VERBOSELEVEL =~ ^[1-2]$ ]] && {
    echo DEFAULT == $DEFAULT
    echo ALL == $ALL
    echo ANALYTICS == $ANALYTICS
};

# the default is to deploy all stacks
ALL=$(( $ALL || $DEFAULT ))

# Logic for which stacks are deployed based on the features needed
CFNMAIN=$(( $ALL ))
CFNANALYTICS=$(( $ALL || $ANALYTICS ))

# if verbose 2 only
[[ ! $VERBOSELEVEL =~ ^2$ ]] && {
    echo CFNMAIN = $CFNMAIN
    echo CFNANALYTICS = $CFNANALYTICS
};

[[ $CFNMAIN ]] && {
    echo cdk synth cfnMain
    echo cdk deploy $REQUIREAPPROVAL cfnMain
};

[[ $CFNANALYTICS ]] && {
    echo cdk synth cfnAnalytics
    echo cdk deploy $REQUIREAPPROVAL cfnAnalytics
};

echo ":) Deployment complete"

slycordinator · 2021-11-09T09:39:22Z

#!/bin/sh

DIRNAME=$(dirname -- $0)
BASENAME=$(basename -- $0)

usage()
{
echo "USAGE: $BASENAME [OPTIONS]"
echo
echo "OPTIONS"
echo " -r, --require-approval Ask user for security approval when deploying CDK stacks"
echo
echo " Features deployed will be the sum (union) of the following options, if none"
echo " is specified then all features will be deployed by default. (Specify each"
echo " option separately, as a group like -yld will not be understood)"
echo " -a, --all Deploy all features"
echo " -y, --analytics Deploy the analytics features"
echo
echo " -v, --verbose [level] Output additional info. (can use -v=2 form also)"
echo " Possible levels:"
echo " 0 (default) essential info"
echo " 1 more info"
echo " 2 even more info"
echo
echo "POSITIONAL PARAMETERS"
echo " none"
exit
}

default values for flags. always use 1 for true and 0 for false. use strings for qualifiers.

REQUIREAPPROVAL="--require-approval never"
DEFAULT=1
ALL=0
ANALYTICS=0
VERBOSELEVEL="0"

while [[ $# > 0 ]]
do
echo num $#
[[ $1 =~ ^-h$|^--help$ ]] && {
usage
};
# -- marks end of options and start of positional parameters
[[ $1 == -- ]] && { shift; break; };
# options without parameters
[[ $1 =~ ^-r$|^--require-approval$ ]] && { REQUIREAPPROVAL=; shift 1; continue; };
[[ $1 =~ ^-a$|^--all$ ]] && { ALL=1; DEFAULT=0; shift 1; continue; };
[[ $1 =~ ^-y$|^--analytics$ ]] && { ANALYTICS=1; DEFAULT=0; shift 1; continue; };

# verbose option with optional value. e.g. -v, -v 0, -v 1, --verbose, --verbose 1
[[ $1 =~ ^-v$|^--verbose$ ]] && {
    shift 1
    [[ $# == 0 ]] && { continue; };
    VERBOSELEVEL="$1"
};

# verbose option with = value. e.g. -v=0, -v=1, -v=2, --verbose=1 etc.
[[ $1 =~ ^-v=|^--verbose= ]] && {
    VERBOSELEVEL="${1#*=}"
    shift 1
    continue;
};

break;
done

validate string parameters

[[ ! $VERBOSELEVEL =~ ^[0-2]$ ]] && {
echo illegal --verbose parameter $VERBOSELEVEL
usage
};

if verbose 1 or 2

[[ ! $VERBOSELEVEL =~ ^[1-2]$ ]] && {
echo DEFAULT == $DEFAULT
echo ALL == $ALL
echo ANALYTICS == $ANALYTICS
};

the default is to deploy all stacks

ALL=$(( $ALL || $DEFAULT ))

Logic for which stacks are deployed based on the features needed

CFNMAIN=$(( $ALL ))
CFNANALYTICS=$(( $ALL || $ANALYTICS ))

if verbose 2 only

[[ ! $VERBOSELEVEL =~ ^2$ ]] && {
echo CFNMAIN = $CFNMAIN
echo CFNANALYTICS = $CFNANALYTICS
};

[[ $CFNMAIN ]] && {
echo cdk synth cfnMain
echo cdk deploy $REQUIREAPPROVAL cfnMain
};

[[ $CFNANALYTICS ]] && {
echo cdk synth cfnAnalytics
echo cdk deploy $REQUIREAPPROVAL cfnAnalytics
};

echo ":) Deployment complete"

It's marked as /bin/sh, but will not work in posix compliant shells (such as dash).
The "[[ ]]" for comparisons, "~=" regex matching, and "==" instead of "=" are all not supported.

If you prefer using those to the posix equivalents, the easiest thing to do would be to just change it to /bin/bash since those are bashisms.

:)

alanmur · 2021-11-09T18:42:47Z

/bin/bash it is, then!

	#!/bin/sh

	#
	# a simple way to parse shell script arguments
	#
	# please edit and use to your hearts content
	#


	ENVIRONMENT="dev"
	DB_PATH="/data/db"

	function usage()
	{
	echo "if this was a real script you would see something useful here"
	echo ""
	echo "./simple_args_parsing.sh"
	echo "\t-h --help"
	echo "\t--environment=$ENVIRONMENT"
	echo "\t--db-path=$DB_PATH"
	echo ""
	}

	while [ "$1" != "" ]; do
	PARAM=`echo $1 \| awk -F= '{print $1}'`
	VALUE=`echo $1 \| awk -F= '{print $2}'`
	case $PARAM in
	-h \| --help)
	usage
	exit
	;;
	--environment)
	ENVIRONMENT=$VALUE
	;;
	--db-path)
	DB_PATH=$VALUE
	;;
	*)
	echo "ERROR: unknown parameter \"$PARAM\""
	usage
	exit 1
	;;
	esac
	shift
	done


	echo "ENVIRONMENT is $ENVIRONMENT";
	echo "DB_PATH is $DB_PATH";

jehiah/simple_args_parsing.sh

stancufm commented May 12, 2017

tchalvak commented Jun 29, 2017

gperreymond commented Sep 28, 2017 •

edited

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migaes commented Apr 9, 2018 •

edited

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justme-justus commented May 31, 2018

elliotboney commented Jul 17, 2018

LeeYunhang commented Sep 11, 2018

LeeYunhang commented Sep 11, 2018

BatmanAoD commented Jan 8, 2019

kthoms commented Jan 22, 2019

Yann-Situ commented Jun 27, 2019

Pagliacii commented Apr 10, 2020

Ivancaminal72 commented Apr 27, 2020

cslycord commented Apr 30, 2020 •

edited

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unfor19 commented Jul 23, 2020

ko1nksm commented Nov 8, 2020 •

edited

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alanmur commented Nov 8, 2021 •

edited

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slycordinator commented Nov 9, 2021

alanmur commented Nov 9, 2021

jehiah/simple_args_parsing.sh

stancufm commented May 12, 2017

tchalvak commented Jun 29, 2017

gperreymond commented Sep 28, 2017 • edited Loading

migaes commented Apr 9, 2018 • edited Loading

justme-justus commented May 31, 2018

elliotboney commented Jul 17, 2018

LeeYunhang commented Sep 11, 2018

LeeYunhang commented Sep 11, 2018

BatmanAoD commented Jan 8, 2019

kthoms commented Jan 22, 2019

Yann-Situ commented Jun 27, 2019

Pagliacii commented Apr 10, 2020

Ivancaminal72 commented Apr 27, 2020

cslycord commented Apr 30, 2020 • edited Loading

unfor19 commented Jul 23, 2020

ko1nksm commented Nov 8, 2020 • edited Loading

alanmur commented Nov 8, 2021 • edited Loading

slycordinator commented Nov 9, 2021

default values for flags. always use 1 for true and 0 for false. use strings for qualifiers.

validate string parameters

if verbose 1 or 2

the default is to deploy all stacks

Logic for which stacks are deployed based on the features needed

if verbose 2 only

alanmur commented Nov 9, 2021

gperreymond commented Sep 28, 2017 •

edited

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migaes commented Apr 9, 2018 •

edited

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cslycord commented Apr 30, 2020 •

edited

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ko1nksm commented Nov 8, 2020 •

edited

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alanmur commented Nov 8, 2021 •

edited

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