centos memory usage one liner

centos_memory_usage_one_liner

// memory usage percent (integral)
free | awk 'NR==2' | awk '{print int($3/$2*100)}'

// actual memory usage (integral)
// http://open-groove.net/linux-command/free/
free | awk 'NR==2' | awk '{print int(($3-($6+$7))/$2*100)}'

// swap memory usage percent (integral)
free | awk 'NR==4' | awk '{print int($3/$2*100)}'

// total memory usage percent (integral)
free -t | awk 'NR==5' | awk '{print int($3/$2*100)}'