Shell script to Check Ping And Open ports

#Script to Check Ping To Remote Host And Open ports
#!/bin/bash

    # check if service name passed to script as argument, if there no arguments (0) do next

    if [ "$#" = "0" ];

    then

    #write to terminal usage

    echo “Usage: $0 ”

    #since no arguments – we need to exit script and user re-run

    exit 1
    fi

    #writing parameters to variables

    host=$1
    port=$2
    email=”test@expertslogin.com”
    subject=”Script result”

    #Check if ping ok -q to quite mod, -c 4 for 4 checks

    if ping -q -c 4 $host >/dev/null
    then
    # next lines writes result variable

    ping_result=”OK”
    else
    ping_result=”NOT OK”

    fi #end of fi loop

    #next command check if port opened via nc command, and getting exit status of nc command

    nc_result=`nc -z $host $port; echo $?`

    #check of exit status of nc command, and write results to variables

    if [ $nc_result != 0 ];
    then
    port_result=”not opened”
    else
    port_result=”opened”
    fi #exit of fi loop

    #writing message that script will email and write to output

    message=”Ping to host – ${ping_result}, port $port ${port_result}.”

    #next check if ping or port check is failed (ping if not OK and exit status of nc if not 0)

    if [ "$ping_result" != "OK" -o "$nc_result" != "0" ];
    then
    echo “$message” #this line write warning message to terminal

    echo “$message” | mail -s “$subject” $email #this line send email

    fi

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TEST NOW-----

Ping to localhost and check is 22 port opened (ssh server)

    desktop:~/$ ./script 127.0.0.1 22
    Ping to host – OK, port 22 not opened.
    desktop:~/$

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