#!/usr/bin/perl5

# usage: mrtg-getinfo-mem [ -m ]
#
# -m  mem info (mem used, - buffers)
#     default is to output overview of vm used (mem used, swap used)
#
# This script polls information from some /proc files and outputs the polled
# information in a format usable by mrtg. It can also function as a required
# file, in which case it will gather the data from /proc but not output
# anything to stdout.

open(MEMINFO, "/proc/meminfo") || die("/proc/meminfo: $!\nstopped");
while (<MEMINFO>) {
   if (/^Mem: +(\d+) +(\d+) +(\d+) +(\d+) +(\d+) +(\d+)/) {
      ($mem_total, $mem_used, $mem_free, $mem_shared, $mem_buffers, $mem_cached) = ($1, $2, $3, $4, $5, $6);
   } elsif (/^Swap: +(\d+) +(\d+) +(\d+)/) {
      ($swap_total, $swap_used, $swap_free) = ($1, $2, $3);
   }
}
close(MEMINFO);

open(UPTIME, "/proc/uptime") || die("/proc/uptime: $!\nstopped");
<UPTIME> =~ /^(\d+)/;
$uptime = $1;
close(UPTIME);

open(HOSTNAME, "/proc/sys/kernel/hostname") || die("/proc/sys/kernel/hostname: $!\nstopped");
$hostname = <HOSTNAME>;
chomp $hostname;
close(HOSTNAME);

# See if we are being require'd from another perl5 program.
# If we are, we expect caller(0) to return non-null information;
# in particular, $subroutine should be "(eval)" (by empirical observation).

($package, $filename, $line, $subroutine, $hasargs, $wantargs) = caller(0);
if (! defined $subroutine) {
   require 'getopts.pl';
   Getopts("ms");

   if ($opt_m) {
      printf("%d\n%d\n", $mem_used, $mem_used - $mem_buffers - $mem_cached)
   } else {
      printf("%d\n%d\n", $mem_used, $swap_used)
   }
   if ($uptime >= 86400) {
      my($days) = int($uptime/86400);
      printf("%d day%s, ", $days, $days == 1? "": "s");
   }
   printf("%02d:%02d:%02d\n", ($uptime/3600)%24, ($uptime/60)%60, $uptime%60);
   printf("%s\n", $hostname);
}
1;