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Infinite "while" loop subshell loses current date variable

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# 1  
Old 05-19-2015
Infinite "while" loop subshell loses current date variable
I have a simple script to log network connectivity to a set of systems.

However, as expected the date appended to the log never changes because the new variable is lost when the loop starts again. Can someone clue me in on how to get around this issue?


Code:
#!/bin/bash
LOG=/tmp/netlog
when=`/bin/date`

while true;
do

for server in srv1 srv2 srv3 srv4 srv5;
do

ping -c 1 $server > /dev/null
if [ $? -ne 0 ]; then
 echo "$server-DOWN!" $when >> $LOG.$server
#   mail
else
        echo "$server-UP!" $when >> $LOG.$server
fi
done

done

# 2  
Old 05-19-2015
To execute a command, put it in $( ). You can embed this inside "" quotes like a variable.

i.e.

Code:
echo "$(date +%Y-%m-%d-%H-%M-%S) server down"

I recomend YYYY-MM-DD-HH-MM-SS dates at the beginning of log lines, because they sort and compare so nicely. You'll be able to check if a line is >= "2014-10-10-12-00-00" just with ordinary alphanumeric comparison, etc.
This User Gave Thanks to Corona688 For This Post:
woodson2
# 3  
Old 05-19-2015
Assign "when" inside the loop.
This User Gave Thanks to Scott For This Post:
woodson2
# 4  
Old 05-19-2015
Quote:
Originally Posted by Scott
Assign "when" inside the loop.

So simple..Thanks.

---------- Post updated at 04:04 PM ---------- Previous update was at 04:03 PM ----------

Quote:
Originally Posted by Corona688
To execute a command, put it in $( ). You can embed this inside "" quotes like a variable.

i.e.

Code:
echo "$(date +%Y-%m-%d-%H-%M-%S) server down"

I recomend YYYY-MM-DD-HH-MM-SS dates at the beginning of log lines, because they sort and compare so nicely. You'll be able to check if a line is >= "2014-10-10-12-00-00" just with ordinary alphanumeric comparison, etc.
Thanks, I'll give this a try as well.
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