Ubiquiti ERL script wanted to compare md5 values

JaredBusch

I was making sure a success worked like i thought because i was thinking that writing it to a system log would be good even on success.

scottalanmiller

Oh no, I think you are right, that syntax should work.

JaredBusch

Happy now?

jbusch@jared:~$ md5sum -c /config/bad.md5 && echo "Successful test of MD5" || echo "Failed test of MD5"
/root.dev/squashfs.img: OK
/root.dev/squashfs.o: FAILED
md5sum: WARNING: 1 of 2 computed checksums did NOT match
Failed test of MD5
jbusch@jared:~$ md5sum -c /config/good.md5 && echo "Successful test of MD5" || echo "Failed test of MD5"
/root.dev/squashfs.img: OK
/root.dev/squashfs.o: OK
Successful test of MD5
jbusch@jared:~$

scottalanmiller

Yes better

Don't forget the 2>/dev/null so you only get the result message.

JaredBusch

what is the 2 for? it still printed instead of sending the output to /dev/null

jbusch@jared:~$ md5sum -c /config/good.md5 2>/dev/null && echo "Successful test of MD5" || echo "Failed test of MD5"
/root.dev/squashfs.img: OK
/root.dev/squashfs.o: OK
Successful test of MD5
jbusch@jared:~$ md5sum -c /config/good.md5 > /dev/null && echo "Successful test of MD5" || echo "Failed test of MD5"
Successful test of MD5

scottalanmiller

Argh, I must be getting tired.

The 2 is good but not what we wanted. Just drop the 2 completely. Just >/dev/null

scottalanmiller

That's better, no extraneous junk. Just pass or fail.

scottalanmiller

Now if you want to run that every five minutes or hourly or daily or whatever you can pop it into the crontab and it will run it for you.

JaredBusch

@scottalanmiller said:

Argh, I must be getting tired.

The 2 is good but not what we wanted. Just drop the 2 completely. Just >/dev/null

I did. if you look again. And I even recalled the piping output to dev.null once i seen it fail. Like, oh yeah, I learned this a time or three..

JaredBusch

@scottalanmiller said:

Now if you want to run that every five minutes or hourly or daily or whatever you can pop it into the crontab and it will run it for you.

Yeah, I am thinking weekly to /var/log/ or something on success and the log and email on a problem.

But, now that I am this far on it, I want to look at not having to create the good.md5 on each ERL and after every upgrade (because the value will change). SO, I may need an actual bash script.

But that is not for tonight.

JaredBusch

Posted over on the UBNT forums.. We'll see what happens. I am heading to bed i think.

scottalanmiller

Good night.