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Use ping to test if a server is up

Terminal - Use ping to test if a server is up
if [ "$(ping -q -c1 google.com)" ];then wget -mnd -q http://www.google.com/intl/en_ALL/images/logo.gif ;fi
2010-03-23 04:15:03
User: alf
Functions: wget
-1
Use ping to test if a server is up

Bash scrip to test if a server is up, you can use this before wget'ing a file to make sure a blank one isn't downloaded.

Alternatives

There are 5 alternatives - vote for the best!

Terminal - Alternatives

Know a better way?

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What others think

If you're not going to have an "else" clause, you can shorten that to:

[ "$(ping -q -c1 google.com)" ] && wget ...

'if' works by using the '[' (test) command, but you can use it directly.

Comment by flatcap 234 weeks and 1 day ago

Alternatively (not as pretty):

ping -c1 google.com > /dev/null && wget ...
Comment by flatcap 234 weeks and 1 day ago

Wouldn't it be better to use curl -I to check the headers for a 200 OK? Just because a machine is responding to pings, that doesn't mean that the webserver is up.

Comment by eightmillion 234 weeks and 1 day ago

I don't have the means to test this example at the moment, but I believe it should work.

curl -Is google.com 2>&1 | grep -q "200 OK" && wget ...
Comment by eightmillion 234 weeks and 1 day ago

Great alternatives, I'll have to give these a try!

Comment by alf 234 weeks and 1 day ago

'if' expects a command. '[' is actually a program, not part of the shell. So you can actually just do

if ping -q -c1 google.com; then ...
Comment by recursiverse 234 weeks ago

No need for the 'then' or even an 'else', just use && or ||

e.g.:

ping -c1 host.com > /dev/null && echo "YES" || echo "NO"

This is the equivalent of:

if ping -c1 host .com > /dev/null then echo "YES" else echo "NO" fi
Comment by finkployd 205 weeks and 6 days ago

Your point of view

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