mem_info extraction in perl

mem_info.pl

        my @meminfo = `/bin/cat /proc/meminfo`;
        
        
     
        foreach (@meminfo) {
            chomp;
            if (/^Mem(Total|Free):\s+(\d+) kB/) {
                my $counter_name = $1;
                if ($counter_name eq 'Free') {
                    $free_memory_kb = $2;
                }
                elsif ($counter_name eq 'Total') {
                    $total_memory_kb = $2;
                }
            }
            elsif (/^(Buffers|Cached|SReclaimable):\s+(\d+) kB/) {
                $caches_kb += $2;
            }
        }
        $used_memory_kb = $total_memory_kb - $free_memory_kb;
        
        
        
        /* 
        
The meminfo on a linux system looks like this 

 cat /proc/meminfo
MemTotal:       33570880 kB
MemFree:        17162456 kB
Buffers:          487780 kB
Cached:          7907992 kB
SwapCached:            0 kB
Active:         10313908 kB
Inactive:        2921112 kB
Active(anon):    4937860 kB
Inactive(anon):   536140 kB
Active(file):    5376048 kB
Inactive(file):  2384972 kB
Unevictable:           0 kB
Mlocked:               0 kB
SwapTotal:      16776664 kB
SwapFree:       16776664 kB
Dirty:               960 kB
Writeback:             0 kB
AnonPages:       4839136 kB
Mapped:           751596 kB
Shmem:            634888 kB
Slab:            2176696 kB
SReclaimable:    2096216 kB
SUnreclaim:        80480 kB
KernelStack:        9160 kB
PageTables:            0 kB
NFS_Unstable:          0 kB
Bounce:                0 kB
WritebackTmp:          0 kB
CommitLimit:    33562104 kB
Committed_AS:   17407816 kB
VmallocTotal:   34359738367 kB
VmallocUsed:        6384 kB
VmallocChunk:   34359727640 kB
HardwareCorrupted:     0 kB
DirectMap4k:    33554432 kB
DirectMap2M:           0 kB
 
 
Alternate strategy to extract the same details is to use the vmstat: 

    	my $command_line = `vmstat | tail -1 | awk '{print \$4,\$5}'`;
    	chomp $command_line;
        my @memlist      = split(/ /, $command_line);
    
        # Define the calculating scalars
        $used_memory_kb  = $memlist[0]/1024;
        $free_memory_kb = $memlist[1]/1024;
        $total_memory_kb = $used_memory_kb + $free_memory_kb; 
        
        
        
Note: Scalar conversion 
  vmstat
procs -----------memory---------- ---swap-- -----io---- -system-- -----cpu------
 r  b   swpd   free   buff  cache   si   so    bi    bo   in   cs us sy id wa st
 0  0      0 17161800 487780 10004248    0    0     0     4    0    0  0  0 100  0  0

     */