How to check if ping responded or not in a batch file

Question

I want to continuously ping a server and see a message box when ever it responds i.e. server is currently down. I want to do it through batch file.

I can show a message box as said here http://stackoverflow.com/questions/774175/how-can-i-open-a-message-box-in-a-windows-batch-file/774253#774253

and can ping continuously by

ping <servername> -t

But how do I check if it responded or not?

Answer 1

The following checklink.cmd program is a good place to start. It relies on the fact that you can do a single-shot ping and that, if successful, the output will contain the line:

Packets: Sent = 1, Received = 1, Lost = 0 (0% loss),

By extracting tokens 5 and 7 and checking they're respectively "Received" and "1,", you can detect the success.

@setlocal enableextensions enabledelayedexpansion
@echo off
set ipaddr=%1
:loop
set state=down
for /f "tokens=5,7" %%a in ('ping -n 1 !ipaddr!') do (
    if "x%%a"=="xReceived" if "x%%b"=="x1," set state=up
)
echo.Link is !state!
ping -n 6 127.0.0.1 >nul: 2>nul:
goto :loop
endlocal

Call it with the name (or IP address) you want to test:

checklink 127.0.0.1
checklink localhost
checklink nosuchaddress

---

To only notify you when the state changes, you can use:

@setlocal enableextensions enabledelayedexpansion
@echo off
set ipaddr=%1
set oldstate=neither
:loop
set state=down
for /f "tokens=5,7" %%a in ('ping -n 1 !ipaddr!') do (
    if "x%%a"=="xReceived" if "x%%b"=="x1," set state=up
)
if not !state!==!oldstate! (
    echo.Link is !state!
    set oldstate=!state!
)
ping -n 2 127.0.0.1 >nul: 2>nul:
goto :loop
endlocal

---

However, as Gabe points out in a comment, you can just use ERRORLEVEL so the equivalent of that second script above becomes:

@setlocal enableextensions enabledelayedexpansion
@echo off
set ipaddr=%1
set oldstate=neither
:loop
set state=up
ping -n 1 !ipaddr! >nul: 2>nul:
if not !errorlevel!==0 set state=down
if not !state!==!oldstate! (
    echo.Link is !state!
    set oldstate=!state!
)
ping -n 2 127.0.0.1 >nul: 2>nul:
goto :loop
endlocal

Answer 2

You can ping without "-t" and check the exit code of the ping. It reports failure when there is no answer.

Answer 3

The question was to see if ping responded which this script does.

However this will not work if you get the Host Unreachable message as this returns ERRORLEVEL 0 and passes the check for Received = 1 used in this script, returning Link is UP from the script. Host Unreachable occurs when ping was delivered to target notwork but remote host cannot be found.

If I recall the correct way to check if ping was successful is to look for the string 'TTL' using Find.

@echo off
cls
set ip=%1
ping -n 1 %ip% | find "TTL"
if not errorlevel 1 set error=win
if errorlevel 1 set error=fail
cls
echo Result: %error%

This wont work with IPv6 networks because ping will not list TTL when receiving reply from IPv6 address.