Limit the output of the TOP command to a specific process name

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

Answer 1

I came here looking for the answer to this on OSX. I ended up getting what I wanted with bash and awk:

topfiltered() {
  [[ -z "$1" ]] && return
  dump="/tmp/top_dump"
  rm -f "$dump"
  while :; do
    clear
    [[ -s "$dump" ]] && head -n $(( $LINES - 1 )) "$dump"
    top -l 1 -o cpu -ncols $(( $COLUMNS / 8 )) | awk -v p="$(pgrep -d ' ' $@)" '
        BEGIN { split(p, arr); for (k in arr) pids[arr[k]]=1 }
        NR<=12 || ($1 in pids)
    ' >"$dump"
  done
}

I loop top in logging mode and filter it with awk, building an associative array from the output of pgrep. Awk prints the first 12 lines, where line 12 is the column headers, and then every line which has a pid that's a key in the array. The dump file is used for a more watchable loop.