'mu' is a simple script to get real memory usage (not VSZ, not RSS but PSS) of a given PID or process pattern (uses pgrep).Check these didactic URLs for a nice explanation about memory consumption [1] and cache [2]:[1] http://emilics.com/blog/article/mconsumption.html[2] http://blog.scoutapp.com/articles/2010/10/06/determining-free-memory-on-lin…

mu

#!/bin/bash
#
# Copyright (C) 2013, Roberto C. Morano <rcmova@gmail.com>
# 
# This software is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
# 
# This software is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
# 
# You should have received a copy of the GNU General Public License
# along with this library; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
#
# As a special exception, if you link this library with other files to
# produce an executable, this library does not by itself cause the
# resulting executable to be covered by the GNU General Public License.
# This exception does not however invalidate any other reasons why the
# executable file might be covered by the GNU General Public License.

function get_mu_by_pid() {

    PID=$1
    SMAPS="/proc/$PID/smaps"
    if [[ -z $(head -n3 $SMAPS 2>/dev/null) ]]
    then
        echo "Permission denied for PID $PID"
    fi

    for portion in $(grep Pss $SMAPS | awk '{print $2}'); do MU=$(expr $MU + $portion); done

    if [ ! -z $MU ]
    then
        echo $MU
    else
        echo "Process does not use memory. Yeah, Really!"
    fi

}

PID=$1
MU=""
PID_MAX_LEN=$(cat /proc/sys/kernel/pid_max | wc -L)

if [ -z $PID ]
then
    BASENAME=$(basename $0)
    echo "$BASENAME: missing argument"
    echo "Usage: $BASENAME PID|PROC_PATTERN"
    exit 1
else
    # if pid is not numerical then pgrep string and print every ocurrency
    if [[ -z $(echo $PID | grep "^[0-9]\{1,$PID_MAX_LEN\}$") ]]
    then
        for arg in $(pgrep $PID); do echo "$(get_mu_by_pid $arg) ($arg)"; done
    else
        get_mu_by_pid $PID
    fi
fi