Use bash to implement like C's argc and argv

bash_arguments_example.sh

#!/usr/bin/env bash
# Copyright (C) 2019 by Ben Wei <ben@juluos.org>
# Permission to use, copy, modify, and/or distribute this software for any purpose with or without fee is hereby granted.
# THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, 
# OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF
# CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
######
# sample code of blog
## tested with bash 4.3.48 x86_64-pc-linux-gnu ubuntu-16.04.4 LTS
verbose=0

clog()
{
	if [ $verbose -gt 0 ]; then
	echo $@
	fi
}

syntax()
{
cat << EOF >/dev/stdout
syntax: [options] <message 1> [message 2] [message 3]
options -v verbose of clog
EOF
	exit 1
}

while [ 1 ]; do
	if [[ "$1" =~ "-".* ]]; then
		if [ "$1" == "-v" ]; then
			verbose=1
		fi
		shift
	else
		break
	fi
done

if [ -z "$1" ]; then
	syntax
fi

arguments=("$1" "$2" "$3")
argc=${#arguments[@]}
if [ "$argc" -eq 0 ]; then
	syntax
fi

for ((i=0; i<${argc} ; i++)); do
	if [ "x${arguments[$i]}" = "x" ]; then continue; fi
	clog "input argument[$i]: ${arguments[$i]}"
done

exit 0

executed result

# origin result
 bash bash_arguments_example.sh -v "a b" "ff 11"
input argument[0]: a b
input argument[1]: ff 11


# with debuging option
$ bash -x bash_arguments_example.sh -v "a b" "ff 11"
+ verbose=0
+ '[' 1 ']'
+ [[ -v =~ -.* ]]
+ '[' -v == -v ']'
+ verbose=1
+ shift
+ '[' 1 ']'
+ [[ a b =~ -.* ]]
+ break
+ '[' -z 'a b' ']'
+ arguments=("$1" "$2" "$3")
+ argc=3
+ '[' 3 -eq 0 ']'
+ (( i=0 ))
+ (( i<3  ))
+ '[' 'xa b' = x ']'
+ clog 'input argument[0]: a b'
+ '[' 1 -gt 0 ']'
+ echo input 'argument[0]:' a b
input argument[0]: a b
+ (( i++ ))
+ (( i<3  ))
+ '[' 'xff 11' = x ']'
+ clog 'input argument[1]: ff 11'
+ '[' 1 -gt 0 ']'
+ echo input 'argument[1]:' ff 11
input argument[1]: ff 11
+ (( i++ ))
+ (( i<3  ))
+ '[' x = x ']'
+ continue
+ (( i++ ))
+ (( i<3  ))
+ exit 0