plotmem

#!/bin/zsh -e

interval=2

case $1 in
    --help)
        echo "plotmem: plots the memory usage of a command in real-time using gnuplot"
        echo "Usage: $0 [options] command [command-options]"
        echo "Options:"
        echo "	-i <int>  specify the refresh interval, in seconds (default 2)"
        exit 0;;
    -i)
        shift
        interval=$1
        shift;;
esac

"$@" &
pid=$!
title=$(basename $1)

data=$(mktemp -t plotmem-XXXXX)

trap "rm -f $data" EXIT

procdir=/proc/$pid
echo "# timestamp virtual resident fds" >> $data
first=1
t0=$(date +%s.%N)
fds0=0
echo "$t0 0 0 0" >> $data

plot_loop() {
    while [ -d "$procdir" ]; do
        vmsize=$(awk '/^VmSize:/ { print $2; }' $procdir/status 2>/dev/null || break)
        vmrss=$(awk '/^VmRSS:/ { print $2; }' $procdir/status 2>/dev/null || break)
        fds=$(ls $procdir/fdinfo 2>/dev/null | wc -l)
        if [ "$fds" -eq "$fds0" ]; then fds=""; else fds0=$fds; fi
        date +"%s.%N $vmsize $vmrss $fds" >> $data
        if [ $first -eq 0 ]; then
            echo "replot";
        else
            cat <<EOF
plot "$data" using (\$1-$t0):(\$2/1000) with lines title "Virtual", \
          "" using (\$1-$t0):(0):(\$3/1000) with filledcurves lc rgb "#7777aa" notitle, \
          "" using (\$1-$t0):(\$3/1000) with lines title "Resident", \
          "" using (\$1-$t0):4 with points pt 6 title "Open fds" axes x1y2
EOF
            first=0
        fi
        sleep $interval
    done
}

trap "" 2

catch_stop() {
    trap 2
    plot_loop # should stop once program is dead
    echo "Program killed. Log in $data. Press enter to close and cleanup." >&2
    read
}

{
    echo "set term wxt noraise title \"$title\""
    echo "set title \"$title\""
    echo 'set yrange [0:]'
    echo 'set xlabel "Time (seconds)"'
    echo 'set ylabel "Memory usage (MB)"'
    echo 'set ytics nomirror'
    echo 'set y2range [0:]'
    echo 'set y2tics scale 1'
    echo 'set y2label "Fds"'
    echo 'set key left box'

    trap catch_stop 2
    plot_loop

    trap 2
    echo "Program ended. Log in $data. Press enter to close and cleanup." >&2
    read
} | gnuplot >/dev/null