Create a timeseries TSV of physical memory usage by command name

trackmem.sh

#!/bin/sh
if [ $# -ne 2 ]; then
  exit;
fi

search=$1
delay=$2
header=0
os=$(uname)
if [ "$os" = "Darwin" ]; then
  while true; do
    t=
    for pid in $(pgrep "$search"); do
      if [ $header -eq 0 ]; then
        # time = RFC3339 timestamp
        # pid = process ID
        # physical = current physical memory
        # virtual = current virtual memory
        # search_term = search term
        printf "%s\t%s\t%s\t%s\t%s\n" "time" "pid" "physical" "virtual" "search_term"
        header=1
      fi
      printf "%s\t%s\t%s\t%s\t%s\n" \
        $(TZ=UTC date "+%Y-%m-%dT%H:%M:%SZ") \
        $(ps -o pid=,rss=,vsz= -p $pid | awk 'BEGIN {OFS=" "} {$1=$1; print}' 2>/dev/null) \
        "$search"
    done
    sleep "$delay"
  done
elif [ "$os" = "Linux" ]; then
  while true; do
    t=$(TZ=UTC date "+%Y-%m-%dT%H:%M:%SZ")
    for pid in $(pgrep "$search"); do
      if [ $header -eq 0 ]; then
        # time = RFC3339 timestamp
        # pid = process ID
        # physical = current physical memory
        # peak_physical = peak physical memory
        # virtual = current virtual memory
        # peak_virtual = peak virtual memory
        # search_term = search term
        # command_line = command line
        printf "%s\t%s\t%s\t%s\t%s\t%s\t%s\t%s\n" \
          "time" "pid" "physical" "peak_physical" "virtual" "peak_virtual" "search_term" "command_line"
        header=1
      fi
      printf "%s\t%s\t%s\t%s\t%s\t%s\t%s\t%s\n" \
        $(TZ=UTC date "+%Y-%m-%dT%H:%M:%SZ") \
        $pid \
        $(awk 'BEGIN {OFS=" "} /VmRSS|VmHWM|VmSize|VmPeak/ {x[substr($1,1,length($1)-1)] = $2} END {print x["VmRSS"], x["VmHWM"], x["VmSize"], x["VmPeak"]}' /proc/$pid/status 2>/dev/null) \
        "$search" \
        "$(sed -e "s/\x00/ /g" /proc/$pid/cmdline 2>/dev/null | sed -e "s/ $//")"
    done
    sleep "$delay"
  done
else
  echo "OS not supported" 1>&2
  exit 1
fi

For example, on Linux, tracking current and peak memory use

$ trackmem.sh bash 3
time	pid	physical	peak_physical	virtual	peak_virtual	search_term	command_line
2020-09-04T01:08:25Z	1	3444	3444	4112	4112	bash	bash
2020-09-04T01:08:28Z	1	3444	3444	4112	4112	bash	bash

On MacOS, only able to track current memory use

$ trackmem.sh bash 3
time	pid	physical	virtual	search_term
2020-09-04T01:07:49Z	21288	504	4296812	bash
2020-09-04T01:07:49Z	58937	404	4296812	bash
2020-09-04T01:07:49Z	78589	712	4296812	bash
2020-09-04T01:07:49Z	98061	1352	4296812	bash
2020-09-04T01:07:49Z	99640	736	4296812	bash
2020-09-04T01:07:52Z	21288	504	4296812	bash
2020-09-04T01:07:52Z	58937	404	4296812	bash
2020-09-04T01:07:52Z	78589	712	4296812	bash
2020-09-04T01:07:53Z	98061	1352	4296812	bash
2020-09-04T01:07:53Z	99640	736	4296812	bash