waiter

#!/bin/bash
#waiter script (L) 8^12

MESSAGE="Wait"
WTIMEOUT=0
ITEM_ARR=0 #current item counter

CH_S[0]='-' #pseudographic items
CH_S[1]='/'
CH_S[2]='|'
CH_S[3]='\'

print_help()
{
    echo "use waiter <time> [message]"
    echo "<time> - wait time"
    echo "[message] - optional text message"
}

#parameters check

if [ -z $1 ];then #if no parameters
    print_help
    exit 2
fi

#if help request
if [ $1 = "-h" ];then
    print_help
    exit 2
fi

if [ $1 = "--help" ];then
    print_help
    exit 2
fi

if [ -n "$2" ];then
    MESSAGE=$2
fi

if (echo $1 | grep -E -q "^?[0-9]+$");then
    WTIMEOUT=$1
else
    echo "Not a number in first parameter <time>"
    exit 1
fi

echo -n $MESSAGE" ("$WTIMEOUT" secounds): "
tput sc #save cursor position

while [ $WTIMEOUT -ge 0 ]; do

    #print timeout and current pseudographic char
    printf '%3s %s' $WTIMEOUT ${CH_S[ITEM_ARR]}
    tput rc #restore cursor position
    sleep 1

    #decrease timeout and increase current item ctr.
    let "WTIMEOUT=WTIMEOUT-1"
    let "ITEM_ARR=ITEM_ARR+1"

    if [ $ITEM_ARR -eq 4 ];then
    #if items ctr > number of array items
    #starting with 0 item
    let "ITEM_ARR=0"
    fi

done

#next message starting with new string
printf '\n'