#! /bin/sh
if [ $# -lt 1 ];  then
    echo "usage $0 cmd or $0 -p PID";
    exit  1;
fi

if [ "$1X" = "-pX" ]; then
    PID=$2
else
    $1 & PID=$!
fi

STATUS_FILE="/proc/$PID/status"
LOG_FILE="${PID}.dat"
PLOT_FILE="${PID}.plt"

draw() {
    cat << EOF >$PLOT_FILE
set term postscript
set output "$PID.ps"
plot '${LOG_FILE}' using 1:2 with lines title 'VmSize', \
'${LOG_FILE}' using 1:3 with lines title 'VmRss', \
'${LOG_FILE}' using 1:4 with lines title 'VmLib'
set term x11
replot
EOF

    gnuplot -persist $PLOT_FILE
    exit 0
}

trap draw SIGINT

CPT=0
while [ 1 ]; do
    if [ ! -e $STATUS_FILE ]; then break; fi
    awk "BEGIN{ vmSize=0; vmRss=0; vmLib=0; }
    /VmSize/ {vmSize = \$2 }
    /VmRSS/ { vmRss = \$2 }
    /VmLib/ { vmLib = \$2 }
    END { print $CPT\" \"vmSize\" \"vmRss\" \"vmLib }
    " $STATUS_FILE >> $LOG_FILE
    sleep 1
    ((CPT=CPT+1));
done

draw