bin/memory

#!/bin/bash
#
# z3bra - (c) wtfpl 2014

usage () {
    cat <<EOF
usage: $(basename $0) [-hptu]
    -h : print help
    -p : percentage of memory used (default)
    -t : total available memory
    -u : memory used (human-readable)
EOF
}

# display the total of available memory in human readable format
memtotal () {
    read mem <<< `grep -E 'MemTotal' /proc/meminfo |awk '{print $2}'`

    if [ $mem -gt 1048576 ]; then
        mem=`bc <<< "scale=2; $mem / 1048576"`
        mem="${mem}G"
    elif [ $mem -gt 1024 ]; then
        mem=`bc <<< "$mem / 1024"`
        mem="${mem}M"
    fi

    echo $mem
}

# display the memory used in human readable format
memused () {
    read t f <<< `grep -E 'Mem(Total|Free)' /proc/meminfo |awk '{print $2}'`
    read b c <<< `grep -E '^(Buffers|Cached)' /proc/meminfo |awk '{print $2}'`
    mem=`bc <<< "($t - $f - $c - $b)"`

    if [ $mem -gt 1048576 ]; then
        mem=`bc <<< "scale=2; $mem / 1048576"`
        mem="${mem}G"
    elif [ $mem -gt 1024 ]; then
        mem=`bc <<< "$mem / 1024"`
        mem="${mem}M"
    fi

    echo $mem
}

# display the memory used in percentage
memperc () {
    read t f <<< `grep -E 'Mem(Total|Free)' /proc/meminfo |awk '{print $2}'`
    read b c <<< `grep -E '^(Buffers|Cached)' /proc/meminfo |awk '{print $2}'`
    mem=`bc <<< "100 * ($t - $f - $c - $b) / $t"`

    echo "${mem}%"
}


case $1 in
    -h) usage;;
    -t) memtotal;;
    -u) memused;;
     *) memperc;;
 esac