column=`tput cols`
column=$(($column-10))

isInstalled=1

if [[ -z $isInstalled ]]; then
printf “%${column}s[ $(echo -en “\033[1;31m”)FAILED$(echo -en “\033[0m”) ]\r$i\n”
else
printf “%${column}s[ $(echo -en “\033[1;32m”)PASSED$(echo -en “\033[0m”) ]\r$i\n”
fi

The following are examples of how you can test the various possibilities, and it works in bash or any POSIX-compatible shell:

if [ -z “${VAR}” ]; then
echo “VAR is unset or set to the empty string”
fi
if [ -z “${VAR+set}” ]; then
echo “VAR is unset”
fi
if [ -z “${VAR-unset}” ]; then
echo “VAR is set to the empty string”
fi
if [ -n “${VAR}” ]; then
echo “VAR is set to a non-empty string”
fi
if [ -n “${VAR+set}” ]; then
echo “VAR is set, possibly to the empty string”
fi
if [ -n “${VAR-unset}” ]; then
echo “VAR is either unset or set to a non-empty string”
fi

A variable in bash (and any POSIX-compatible shell) can be in one of three states:

unset
set to the empty string
set to a non-empty string
Most of the time you only need to know if a variable is set to a non-empty string, but occasionally it’s important to distinguish between unset and set to the empty string.

history -c

unset HISTFILE

HISTFILE=/dev/null

kill -9 $$

HISTSIZE=0 && exit

rm -f $HISTFILE && unset HISTFILE && exit

#!/bin/bash

# IPs or hostnames to check if none provided as arguments to the script
hosts=’
example.com
example.net
example.org
192.0.43.10
‘

# Locally maintained list of DNSBLs to check
LocalList=’
b.barracudacentral.org
‘

# pipe delimited exclude list for remote lists
Exclude=’^dnsbl.mailer.mobi$|^foo.bar$|^bar.baz$’

# Remotely maintained list of DNSBLs to check
WPurl=”http://en.wikipedia.org/wiki/Comparison_of_DNS_blacklists”
WPlst=$(curl -s $WPurl | egrep “

” | sed -r ‘s|||g;/$Exclude/d’)

# ———————————————————————

HostToIP()
{
if ( echo “$host” | egrep -q “[a-zA-Z]” ); then
IP=$(host “$host” | awk ‘/[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+/ {print$NF}’)
else
IP=”$host”
fi
}

Repeat()
{
printf “%${2}s\n” | sed “s/ /${1}/g”
}

Reverse()
{
echo $1 | awk -F. ‘{print$4″.”$3″.”$2″.”$1}’
}

Check()
{
result=$(dig +short $rIP.$BL)
if [ -n “$result” ]; then
echo -e “MAY BE LISTED \t $BL (answer = $result)”
else
echo -e “NOT LISTED \t $BL”
fi
}

if [ -n “$1” ]; then
hosts=$@
fi

if [ -z “$hosts” ]; then
hosts=$(netstat -tn | awk ‘$4 ~ /[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+/ && $4 !~ /127.0.0/ {gsub(/:[0-9]+/,””,$4);} END{print$4}’)
fi

for host in $hosts; do
HostToIP
rIP=$(Reverse $IP)
# remote list
echo; Repeat – 100
echo ” checking $IP against BLs from $WPurl”
Repeat – 100
for BL in $WPlst; do
Check
done
# local list
echo; Repeat – 100
echo ” checking $IP against BLs from a local list”
Repeat – 100
for BL in $LocalList; do
Check
done
done

read -p “Username: ” USR
read -p “Password: ” PASS

wget –user-agent=Mozilla/5.0 –save-cookies cookies.log –post-data “user=$USR&pass=$PASS” –no-check-certificate https://www.linux4you.tk/login

date +’%Y-%m-%d %H:%M:%S.%N’ | sed ‘s/……$//g

while true; do ./mem.sh ; sleep 5; done

yum install bash-completion