Recently I rewrote one of my Bash Shell Scripts that blocks TOR proxy exit nodes. It does this by doing numerous DROPs in IPTABLES and because of this, it take 1 minute or so to go through all of them. I decided that it would be nice to have a progress bar display in the shell while it was running to give me an idea how far along it was (You can see the final script at the bottom of this post).

I started to look around for some BASH scripts that have a progress bar and I found 2 notable ones; the first one is called Bar and the second PV (Pipe Viewer). These were nice but I actually needed something that was more based on strictly elements in an array. I reused some code and then optimized it a bit and I got something that is not only very customizable but also will resize the progress bar depending on the window size, much like WGET’s progress bar. The code is here:

Source code

 
lib_progress_bar() {
	local current=0
	local max=100
	local completed_char="#"
	local uncompleted_char="."
	local decimal=1
	local prefix=" ["
	local suffix="]"
	local percent_sign="%"
	local max_width=$(tput cols)
 
	local complete remain subtraction width atleast percent chars
	local padding=3
 
	local OPTIND
 
	while getopts c:u:d:p:s:%:m:hV flag; do
		case "$flag" in
			c) completed_char="$OPTARG";;
			u) uncompleted_char="$OPTARG";;
			d) decimal="$OPTARG";;
			p) prefix="$OPTARG";;
			s) suffix="$OPTARG";;
			%) percent_sign="$OPTARG";;
			m) max_width="$OPTARG";;
 
			(h) lib_help;;
			(V) echo "$lib_script_name: version $Revision$ ($Date$)"; exit 0;;
			(*) lib_usage;;
		esac
	done
	shift $((OPTIND-1))
 
	current=${1:-$current}
	max=${2:-$max} 
 
	if (( decimal > 0 )); then
		(( padding = padding + decimal + 1 ))
	fi
 
	let subtraction=${#completed_char}+${#prefix}+${#suffix}+padding+${#percent_sign}
	let width=max_width-subtraction
 
	if (( width < 5 )); then
		(( atleast = 5 + subtraction ))
		echo >&2 "the max_width of ($max_width) is too small, must be atleast $atleast"
		return 1
	fi
 
    if (( current > max ));then
        echo >&2 "current value must be smaller than max. value"
        return 1
    fi
 
    percent=$(awk -v "f=%${padding}.${decimal}f" -v "c=$current" -v "m=$max" 'BEGIN{printf('f', c / m * 100)}')
 
    (( chars = current * width / max))
 
    # sprintf n zeros into the var named as the arg to -v
    printf -v complete '%0*.*d' '' "$chars" ''
    printf -v remain '%0*.*d' '' "$((width - chars))" ''
 
    # replace the zeros with the desired char
    complete=${complete//0/"$completed_char"}
    remain=${remain//0/"$uncompleted_char"}
 
    printf '%s%s%s%s %s%s\r' "$prefix" "$complete" "$remain" "$suffix" "$percent" "$percent_sign"
 
	if (( current >= max )); then
		echo ""
	fi
}
 
if [ ! -z $1 ] && [ $lib_script_name = "lib_main" ]; then
	"$1" "$2" "$3" "$4" "$5" "$6" "$7" "$8" "$9" "${10}" "${11}" "${12}" "${13}" "${14}" "${15}"
fi

Here are some examples to demostrate how it works:

Source code

# [#########################################..........................................] 50.0%
for i in {1..100}; do
	lib_progress_bar $i 100
done

Source code
   
# [@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@__________________________________________] 50.0%
for i in {1..100}; do
	lib_progress_bar -c '@' -u ' ' $i 100
done

Source code
   
#   (******************************                            ) 50 percent
for i in {1..754}; do
	lib_progress_bar -c '*' -u '-' -d 0 -p '   (' -s ')' -% ' percent' -m 75 $i 754
done

Source code
   
#|******.......|-- 50.00%
for i in {1..100}; do
	lib_progress_bar -c '*' -u '.' -d 2 -p '|' -s '|--' -% ' ' -m 25 $i 100
done

Source code
   
# [######################----------------------] 51.43%
for i in {1..1241}; do
	lib_progress_bar -d 2 -m 55 $i 1241
done
Finally, here is a real-world example showing how to use it for blocking TOR nodes:
Source code
   
#!/bin/bash
 
IPTABLES_TARGET="DROP"
IPTABLES_CHAINNAME="TOR"
 
WORKING_DIR="/tmp/"
 
# get IP address of eth0 network interface
IP_ADDRESS=$(ifconfig eth0 | awk '/inet addr/ {split ($2,A,":"); print A[2]}')
 
if ! iptables -L "$IPTABLES_CHAINNAME" -n >/dev/null 2>&1 ; then			#If chain doesn't exist
	iptables -N "$IPTABLES_CHAINNAME" >/dev/null 2>&1				#Create it
fi
 
cd $WORKING_DIR
 
wget -q -O - http://proxy.org/tor_blacklist.txt -U NoSuchBrowser/1.0 > temp_tor_list1
sed -i 's|RewriteCond %{REMOTE_ADDR} \^||g' temp_tor_list1
sed -i 's|\$.*$||g' temp_tor_list1
sed -i 's|\\||g' temp_tor_list1
sed -i 's|Rewrite.*$||g' temp_tor_list1
 
wget -q -O - "https://check.torproject.org/cgi-bin/TorBulkExitList.py?ip=$IP_ADDRESS&port=80" -U NoSuchBrowser/1.0 > temp_tor_list2
wget -q -O - "https://check.torproject.org/cgi-bin/TorBulkExitList.py?ip=$IP_ADDRESS&port=9998" -U NoSuchBrowser/1.0 >> temp_tor_list2
sed -i 's|^#.*$||g' temp_tor_list2
 
iptables -F "$IPTABLES_CHAINNAME"
 
CMD=$(cat temp_tor_list1 temp_tor_list2 | uniq | sort)
UBOUND=$(echo "$CMD" | grep -cve '^\s*$')
 
for IP in $CMD; do
	let COUNT=COUNT+1
	lib_progress_bar $COUNT $UBOUND
	iptables -A "$IPTABLES_CHAINNAME" -s $IP -j $IPTABLES_TARGET
done
 
iptables -A "$IPTABLES_CHAINNAME" -j RETURN
 
rm temp_tor*
	


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I have updated to the jQ theme by http://devolux.nh2.me/.

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Back again
Brian’s back
tell a friend

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