Tips and tricks: How do I capture the output of “top” to a file?
by the editorial team
The command top is a very useful tool to capture information about process running on Linux. Many times this information may need to be captured to a file. This can be done with the following command:
top -b -n1 > /tmp/top.txt
This will run top once write the output to a file and exit.
The command top can also be run so that it will give multiple reports. To run top 5 times and wait 5 seconds between each output the command would be:
top -b -n5 -d5 > /tmp/top.txt
April 16th, 2008 at 2:34 pm
This is a very simple, but very helpful tip. Thanks!
April 21st, 2008 at 7:11 pm
[…] Fonte: Red Hat Magazine […]
April 26th, 2008 at 12:06 am
Just to point out that you certainly can use pipes too.
Here’s snippet from my quick radiusguard script that makes sure radiusd stays running and does not take more than 20% of the cpu.
…
runlevel=$(who -r | sed ’s/.*run-level *\([3-5]\) .*$/\1/’)
if [ $(chkconfig –list radiusd | grep -c “$runlevel:on”) -eq 1 ]; then
# get radiusd cpu usage
CPU_USAGE=$(top -b -n 1 |\
awk ‘/^[0-9]+ radiusd/ { cpu = $9 }
END { printf(”%i\n”, length(cpu) == 0 ? -1 : cpu); }’)
export CPU_USAGE
echo “$CPU_USAGE” >/var/tmp/radiusguard.last
if [ $CPU_USAGE -eq -1 ]; then
act ’service radiusd stop ; service radiusd start’
else
if [ $CPU_USAGE -ge 20 ]; then
act ’service radiusd restart’
fi
fi
fi
act is a function that sends email on event including outputs of the commands run. Runlevel is checked against chkconfig so that it won’t run berzerk when startup script is intentionally disabled or similar situations.
Needed that script before last upgrade with radius, it just was occationally acting a cpu hog or died mysterioysly. Cpu hogging was really bad, it rendered the LDAP service in the same host unuseable.
Cheers,
:-) riku
May 9th, 2008 at 8:31 am
This command is similar to ps command
give ps -el > /usr/process.txt