Limit the output of the TOP command to a specific

Question

If you call the top command, you get all the running processes. But how can I limit the output only to a certain process name like "java"?

I've tried this top -l 2 | grep java but in this way you get only snapshots and not a continuously updated list. And top -l 0 | grep java is not really clear.

Answer 1

Find the pids of the processes you want to monitor and then use the -p option which allows you to provide a list of pids to the top command.

Example:

top -p 18884 -p 18892 -p 18919

  PID USER     PRI  NI  SIZE  RSS SHARE STAT %CPU %MEM   TIME CPU COMMAND
18884 user  25   0  672M  95M  9476 S     0.0  1.1   0:02   1 java
18892 user  25   0 2280M 123M 12252 S     0.0  1.5   0:05   1 java
18919 user  22   0 1492M 198M 28708 S     0.0  2.4   0:07   1 java

(I believe you can also pass in a comma-separated list.)

Answer 2

Expanding on @dogbane's answer, you can get all the PIDs for a named process with pgrep to do the following:

top -p "$(pgrep -d ',' java)"

Answer 3

Using the answer from here I was able to create a one liner

top -pid $(pgrep process_name | sed -e ':a' -e 'N' -e '$!ba' -e 's/\n/ -pid /g')

This works for me on MacOS 10.12 (Sierra)

Answer 4

I prefer the following so I can still use top interactively without having to look up the pids each time I run it:

top -p `pgrep process-name | tr "\\n" "," | sed 's/,$//'`

Of course if the processes change you'll have to re-run the command.

Explanation:

• pgrep process-name returns a list of process ids which are separated by newlines
• tr "\\n" "," translates these newlines into commas, because top wants a comma-separated list of process ids
• sed is a stream editor, and sed 's/,$//' is used here to remove the trailing comma

Answer 5

I solved my problem using:

top -n1 -b | grep "proccess name"

in this case: -n is used to set how many times top will what proccess
and -b is used to show all pids

it's prevents errors like : top: pid limit (20) exceeded

Answer 6

The following code updates a list of processes every 5 seconds via the watch command:

watch -n 5 -t top -b -n 1 -p$(pgrep java | head -20 | tr "\\n" "," | sed 's/,$//')