#!/usr/bin/perl -w
#
# ========================================================================
# sar2rrd.pl
# ------------------------------------------------------------------------
#
# This script can be used to parse sar command output.
# It will create RRDTool archives and graphs.
#
# You can use command line arguments to select the graphs
# and the columns you wish.
#
# ------------------------------------------------------------------------
# Author: Jerome Delamarche (jd@maje.biz - jd@trickytools.com)
# Version: 1.2
# Date: 06 Feb 2007
#
# Changes:
#	Automatically detect RRDTool version to escape colons chars
#	  in graph legend if necessary (from version 1.2 of RRDTool,
#	  it is necessary !)
#	Generated PNG names are prefixed by the hostname
# ------------------------------------------------------------------------
# Version: 1.1
# Date: 25 Jan 2007
#
# Changes:
#	Ignore lines such as "HH:MM:SS   LINUX RESTART"
#	Take care of time given as "HH:MM:SS PM" or "HH:MM:SS AM"
#	  instead of "HH:MM:SS"
#	New command line argument to specify the date format on the
#	  first output line (MDY or DMY)
#	Date field separator can be a '.' or a '/'
# ------------------------------------------------------------------------
# Version: 1.1
# Date: 30 Jan 2007
# ------------------------------------------------------------------------
# TODO: for memory graphing, should use the -b 1024
# ========================================================================
#
use strict;
use Getopt::Std;
use Time::Local;
use Date::Calc qw(Add_Delta_Days);

my $rrdtool      = "/usr/local/rrdtool/bin/rrdtool";
my $rrddir       = "./rrd";
my $imgdir       = "./img";
my $imgwidth	 = 400;
my $imgheight	 = 200;
my $dateformat	 = "MDY";	# format of the date on the 1st output line
my $sarfile	 = "";
my $startdate    = "";
my $enddate	 = "";
my $graph_name_spec = "";
my $graph_col_sign  = "";
my @graph_col_spec  = ();
my $graph_startsec = 0;
my $graph_endsec   = 0;
my $step	 = 0;
my $line_width	 = 1;
my $hostname     = "localhost";
my $starttime    = "";
my $secondtime   = "";
my $endtime   	 = "";
my $measurecount = 0;
my $logarithmic  = "";
my $verbose	 = 0;
my @colors	 = ( "FF0000", "0000FF", "00FFFF", "FF00FF", "FFFF00", "00FF00", "000000", "C0C0C0", "FF8C00", "8FBC8F" );

# "multiple" graphs are stats like Block Device or CPU Usage that indicate one line per item
#14:46:56          DEV       tps  rd_sec/s  wr_sec/s
#14:47:01       dev1-0      0,00      0,00      0,00
#14:47:01       dev1-1      0,00      0,00      0,00

my %sarstats	 = (
			"proc_s" => {
					"ignore_col" 	=> undef,
					"title"		=> "Process per Second",
					"unit"		=> "count/s",
					"multiple"	=> 0,
					"keysize"	=> 1,
			},
			"runq_sz" => {
					"ignore_col" 	=> undef,
					"title"		=> "Queue Size and Load Average",
					"unit"		=> "count",
					"multiple"	=> 0,
					"keysize"	=> 1,
			},
			"tps" => {
					"ignore_col" 	=> undef,
					"title"		=> "I/O Transfer Rate",
					"unit"		=> "count/s",
					"multiple"	=> 0,
					"keysize"	=> 1,
			},
			"pgpgin_s" => {
					"ignore_col" 	=> undef,
					"title"		=> "Paging Statistics",
					"unit"		=> "count/s",
					"multiple"	=> 0,
					"keysize"	=> 1,
			},
			"DEV" => {
					"ignore_col" 	=> undef,
					"title"		=> "Block Device Activity",
					"unit"		=> "count/s",
					"multiple"	=> 1,
					"keysize"	=> 1,
			},
			"INTR" => {
					"ignore_col" 	=> undef,
					"title"		=> "Interrupt Count",
					"unit"		=> "count/s",
					"multiple"	=> 1,
					"keysize"	=> 1,
			},
			"IFACE" => {
					"ignore_col" 	=> undef,
					"title"		=> { 
								"rxpck_s" => "Network Statistics",
								"rxerr_s" => "Network Failure Statistics",
							   },
					"unit"		=> "count/s",
					"multiple"	=> 1,
					"keysize"	=> 2,
			},
			"totsck" => {
					"ignore_col" 	=> undef,
					"title"		=> "Socket Statistics",
					"unit"		=> "count",
					"multiple"	=> 0,
					"keysize"	=> 1,
			},
			"kbmemfree" => {
					"ignore_col" 	=> undef,
					"title"		=> "Memory and Swap Utilization",
					"unit"		=> "count",
					"multiple"	=> 0,
					"keysize"	=> 1,
			},
			"frmpg_s" => {
					"ignore_col" 	=> undef,
					"title"		=> "Memory Statistics",
					"unit"		=> "count",
					"multiple"	=> 0,
					"keysize"	=> 1,
			},
			"CPU" => {
					"ignore_col" 	=> undef,
					"title"		=> { 
								"prct_user" => "CPU Utilization",
								"i000_s" => "Interruption Statistics",
							   },
					"unit"		=> "count",
					"multiple"	=> 1,
					"keysize"	=> 2,
			},
			"dentunusd" => {
					"ignore_col" 	=> undef,
					"title"		=> "Inode and Files Statistics",
					"unit"		=> "count",
					"multiple"	=> 0,
					"keysize"	=> 1,
			},
			"cswch_s" => {
					"ignore_col" 	=> undef,
					"title"		=> "Context Switches per Second",
					"unit"		=> "count",
					"multiple"	=> 0,
					"keysize"	=> 1,
			},
			"pswpin_s" => {
					"ignore_col" 	=> undef,
					"title"		=> "Swapping Statistics",
					"unit"		=> "count",
					"multiple"	=> 0,
					"keysize"	=> 1,
			},
		   );
my %opts	 = ();

getopts("?d:i:t:f:oH:W:vS:e:s:g:",\%opts);
if (exists($opts{'?'})) { Usage(); }
if (exists($opts{'d'})) { $rrddir = $opts{'d'}; }
if (exists($opts{'i'})) { $imgdir = $opts{'i'}; }
if (exists($opts{'f'})) { $sarfile = $opts{'f'}; }
if (exists($opts{'t'})) { $dateformat = $opts{'t'}; }
if (exists($opts{'H'})) { $imgheight = $opts{'H'}; }
if (exists($opts{'W'})) { $imgwidth = $opts{'W'}; }
if (exists($opts{'o'})) { $logarithmic = "-o"; }
if (exists($opts{'s'})) { $startdate = $opts{'s'}; }
if (exists($opts{'e'})) { $enddate = $opts{'e'}; }
if (exists($opts{'S'})) { $step = $opts{'S'}; }
if (exists($opts{'v'})) { $verbose = 1; }

# Parameters check:
# should specify multiple files ? a hostname ? a range ? data to process ?
die("'$rrdtool' is not an executable") if ! -x $rrdtool;
die("RRD Directory '$rrddir' is not a writeable directory") if ! -d $rrddir || ! -w $rrddir;
die("Image Directory '$imgdir' is not a writeable directory") if ! -d $imgdir || ! -w $imgdir;
if ($sarfile eq "") {
	print "sar result file not set. Please use -f option\n";
	Usage();
}
die("sar File '$sarfile' is not a readable") if ! -r $sarfile;

if (exists($opts{'g'})) { 
	my @graph_spec_parts = split(/:/,$opts{'g'});
	if (scalar(@graph_spec_parts) < 2) {
		print "Incorrect syntax for '-g' option: should be '-g graphname:(+|-)column,...\n";
		Usage();
	}
	if (!exists($sarstats{$graph_spec_parts[0]})) {
		die("Value of graph specification does not start by a valid statistics name (".$graph_spec_parts[0].")\n");
	}
	$graph_col_sign = substr($graph_spec_parts[1],0,1);
	if ($graph_col_sign ne "-" && $graph_col_sign ne "+") {
		print "Incorrect syntax for '-g' option: should be '-g graphname:(+|-)column,...\n";
		Usage();
	}

	$graph_name_spec = $graph_spec_parts[0];
	@graph_col_spec = split(/,/,substr($graph_spec_parts[1],1));

	# Note: column names cannot be checked (or we must store predefined values somewhere ?)
}

# Added with v1.2:
# Try to determine RRDTool version:
my $version = `$rrdtool | grep Copyright`;
my $dummy;
($dummy,$version) = split(/ /,$version);
my @vparts = split(/\./,$version);
my $special_colon = 1;
if ($vparts[0] < 1 || ($vparts[0] == 1 && $vparts[1] < 2)) {
	$special_colon = 0;
}

# First pass:
# we determine the time range:
print "First Pass: determine the time range...\n";

my $firstline = 1;
my $headerline 	= 0;	# set to 1 when the next line is a header line
my $curdate   = "";
my ($startday,$startmonth,$startyear);
my ($endday,$endmonth,$endyear);
my $first_over = 1;
my $curitem   = "";
my @parts;

open(FD,"<$sarfile") or die("Could not open file '$sarfile' in read mode\n");
print "Processing file '$sarfile':\n";
while (<FD>) {
	chomp;
	if ($_ eq "") { $headerline = 1; next; }

	# Added with v1.1: eliminate lines containing LINUX events
	if ($_ =~ /LINUX/) { next; }

	if ($firstline) {
		$firstline = 0;
		
		# should indicate the day:
		# format is: system version (hostname) DD.MM.YYYY
		# or: system version (hostname) DD/MM/YYYY
		$curdate = $_;
		$curdate =~ s/^.*\(.*\).*([[:digit:]]{2}[\.\/][[:digit:]]{2}[\.\/][[:digit:]]{4}).*$/$1/;

		# Added from v1.2:
		$hostname = $_;
		$hostname =~ s/^.*\((.*)\).*$/$1/;

		#print $curdate,"\n"; die;
		# Added with v1.1:
		if ($dateformat eq "MDY") {
			($startmonth,$startday,$startyear) = split(/[\.\/]/,$curdate);
		}
		elsif ($dateformat eq "DMY") {
			($startday,$startmonth,$startyear) = split(/[\.\/]/,$curdate);
		}
		else {
			die("Unknown Date Format: '$dateformat' (supported format are: MDY and DMY)\n");
		}
		#print "startday=$startday, startmonth=$startmonth, startyear=$startyear\n";
		($endday,$endmonth,$endyear) = ($startday,$startmonth,$startyear);
		$startmonth--;
		next;
	}

	# Multiple spaces are considered as a simple char:
	$_ =~ s/([[:space:]]+)/ /g;
	#print $_,"\n";
	@parts = split(/[[:space:]]/);

	#print $parts[0];

	# First field must be: HH:MM:SS
	if ($parts[0] !~ /[[:digit:]]{2}:[[:digit:]]{2}:[[:digit:]]/) { next; }

	# Added with v1.1: eliminate the 2nd column if it is a AM or a PM:
	if ($parts[1] eq "AM" || $parts[1] eq "PM") {
		Time24(\@parts); 

		# Eliminate the column:
		my $part0 = $parts[0];
		shift(@parts);
		shift(@parts);
		unshift(@parts,$part0);
	}

	if ($headerline) {
		$headerline = 0;

		# Examine next fields:
		shift(@parts);
		my $line = join(' ',@parts);
		if ($curitem ne "" && $curitem ne $line) {
			# we can stop, we got the start/end time by now:
			last;
		}

		# $curitem contains the whole columns except the 1st, because
		# sometimes, the 1st column can be ambiguous (see IFACE)
		$curitem = $line;
		next;	# the starttime starts AFTER the header line
	}

	# Is it the first row of value and the first date ?
	if ($starttime eq "") { $starttime = $parts[0]; }
	elsif ($secondtime eq "" && $starttime ne $parts[0]) { $secondtime = $parts[0]; }
		# Note: we suppose the first and second lines belong to the same day

	# Ignore lines which have identical timestamp (think of multiple CPU !)
	if ($endtime eq "" || $endtime ne $parts[0]) {
		$measurecount++;

		# cross over midnight ?
		if ($starttime gt $parts[0]) {
			if ($first_over) {
				eval {
					($endyear,$endmonth,$endday) = Add_Delta_Days($endyear,$endmonth,$endday,1);
				};
				if ($@) {
					die("Incorrect Date Format on the 1st line\nUse the -t option\n");
				}
				$first_over = 0;
			}
		}
		else {
			$first_over = 1;
		}
	}
	$endtime = $parts[0];
}
close(FD);

# Sanity check:
# we must have a start & endtime and curitem should not be empty:
if ($starttime eq "") { die("Could not determine the Start Time from the output file\n"); }
if ($endtime eq "") { die("Could not determine the End Time from the output file\n"); }
if ($curitem eq "") { die("No Item to graph found in the file\n"); }

print "$measurecount measures detected\n";
my $startsec = timelocal(reverse(split(/:/,$starttime)),$startday,$startmonth,$startyear);
my $secondsec = timelocal(reverse(split(/:/,$secondtime)),$startday,$startmonth,$startyear);
$endmonth--;
my $endsec = timelocal(reverse(split(/:/,$endtime)),$endday,$endmonth,$endyear);
#print "$startday,$startmonth,$startyear\n"; exit(0);

my $user_startsec = 0;
my $user_endsec= 0;
if ($startdate ne "") {
	$user_startsec = CheckDate($startdate,"start");
}
if ($enddate ne "") {
	$user_endsec = CheckDate($enddate,"end");
}
if ($user_startsec && $user_endsec && $user_endsec < $user_startsec) {
	die("The specified end date: $enddate, is anterior to the specified start date: $startdate\n");
}

$graph_startsec = ($user_startsec) ? $user_startsec : $startsec;
$graph_endsec = ($user_endsec) ? $user_endsec : $endsec;

# Second pass:
# create the graphs
print "Second Pass: create the graphs...\n";
print "Range starts from $starttime to $endtime for host $hostname\n";

# Compute the interval (in seconds) between to measures:
my $s = $secondsec - $startsec;
if ($step == 0) {
	$step = $s;
}
else {
	if ($step < $s) {
		die("The specified step ('$step') is less than the interval between two values ('$s')\n");
	}
}
print "Use Interval of $step seconds\n";

# Variables for graphs creation:
my $nextblock 	= 0;
my %graphs	= ();
my $dsheartbeat = 0;
my $dsstring 	= "";
my $rras	= "";

$headerline 	= 0;	# set to 1 when the next line is a header line
$first_over 	= 1;

my $sarstat	= "";
my $graphname 	= "";
my $dsname 	= "";
my $keyname	= "";
my $rrdfile 	= "";
my $cmd 	= "";
my $firstvalue 	= 1;	# skip the 1st value which is never significant with sar

my $title	= "";
my $vlabel	= "";
my $dsnames 	= "";
my $ismultiple  = 0;
my $skip	= ($graph_name_spec ne "") ? 1 : 0;

my $startidx;
my $idx;
my $status;

open(FD,"<$sarfile") or die("Could not open file '$sarfile' in read mode\n");
print "Processing file '$sarfile':\n";
while (<FD>) {
	chomp;
	if ($_ eq "") { $headerline = 1; next };

	# Added with v1.1: eliminate lines containing LINUX events
	if ($_ =~ /LINUX/) { next; }

	# Multiple spaces are considered as a simple char:
	$_ =~ s/([[:space:]]+)/ /g;
	@parts = split(/[[:space:]]/);

	# First field must be: HH:MM:SS
	if ($parts[0] !~ /[[:digit:]]{2}:[[:digit:]]{2}:[[:digit:]]/) { next; }

	# Added with v1.1: eliminate the 2nd column if it is a AM or a PM:
	if ($parts[1] eq "AM" || $parts[1] eq "PM") {
		Time24(\@parts); 

		# Eliminate the column:
		my $part0 = $parts[0];
		shift(@parts);
		shift(@parts);
		unshift(@parts,$part0);
	}

	# Check if current line is the header for a multiple graph:
	if ($nextblock) {
		# if the column name is not in the @graphs array, 
		# add it and create a new graph, otherwise, all the graphs
		# have been created...
		my $graphname = $parts[1];
		if (exists($graphs{$graphname})) {
			$nextblock = 0;
		}
		else {
			$graphs{$graphname} = 1;
			$rrdfile = "$rrddir/$dsname$keyname-$graphname.rrd";
			$cmd = "$rrdtool create $rrdfile -b $startsec -s $step $dsstring $rras";
			MySystem($cmd);
			$firstvalue = 1;
		}
	}

	# Handle header line and determine if we analyze a new statistics:
	if ($headerline) {
		$headerline = 0;

		# Do we need to create a new graph ?
		my $len = scalar(@parts) - 1;
		my $line = join(' ',@parts[1..$len]);
		if ($sarstat ne $line) {
			# Dump the former graph:
			if ($sarstat ne "") {
				CreateImage();
			}

			# Create a new graph:
			$dsname = MakeDSName($parts[1]);
			if ($graph_name_spec ne "") {
				if ($dsname eq $graph_name_spec) {
					print "Analyzing data for $dsname\n";
					$skip = 0;
				}
				else {
					print "Skip data for $dsname\n";
					$sarstat = $line;
					$skip = 1;
					next;
				}
			}
			else {
				print "Analyzing data for $dsname\n";
			}

			# the DS Name depends on the keysize:
			# Sanity check:
			$keyname = "";
			if (!exists($sarstats{$dsname})) {
				die("Unknown dsname: $dsname\n");
			}
			if ($sarstats{$dsname}{'keysize'} > 1) {
				$keyname = MakeDSName($parts[2]);
				$keyname = "-".$keyname;
			}

			$dsheartbeat = 2 * $step;
			$dsstring = "";
			$dsnames  = "";

			# Is it a single or a multiple graph ?
			$ismultiple = $sarstats{$dsname}{'multiple'};
			$startidx = ($ismultiple) ? 2 : 1;

			for ( $idx = $startidx ; $idx < scalar(@parts) ; $idx++ ) {
				my $ds = MakeDSName($parts[$idx]);
				if ($dsstring ne "") { $dsnames .= ":"; }
				$dsstring .= "DS:$ds:GAUGE:$dsheartbeat:0:U ";
				$dsnames .= $ds;
			}

			$rras = "RRA:AVERAGE:0.5:1:$measurecount";

			# Is it a single or a multiple graph ?
			$ismultiple = $sarstats{$dsname}{'multiple'};
			if (!$ismultiple) {
				$rrdfile = "$rrddir/$dsname$keyname.rrd";
				$cmd = "$rrdtool create $rrdfile -b $startsec -s $step $dsstring $rras";
				MySystem($cmd);
				$firstvalue = 1;
			}
			else {
				# we cannot create the RRD now, we must analyse the next lines:
				$nextblock = 1;
				%graphs = ();
			}
		}

		$sarstat = $line;
		next;
	}

	if ($firstvalue) { $firstvalue = 0; next; }
	if ($skip) { next; }

	# did we cross over midnight ?
	if ($starttime gt $parts[0]) {
		if ($first_over) {
			$startmonth++;
			($startyear,$startmonth,$startday) = Add_Delta_Days($startyear,$startmonth,$startday,1);
			$startmonth--;
			$first_over = 0;
		}
	}
	else {
		$first_over = 1;
	}

	# This is a measure line: we must update the graph
	$secondsec = timelocal(reverse(split(/:/,$parts[0])),$startday,$startmonth,$startyear);
	my $DATA = "$secondsec:";
	$startidx = ($ismultiple) ? 2 : 1;
	for ( $idx = $startidx ; $idx < scalar(@parts) ; $idx++ ) {
		$parts[$idx] =~ s/,/\./g;
		if ($idx > $startidx) { $DATA.= ":"; }
		$DATA .= $parts[$idx];
	}
	if ($ismultiple) {
		$rrdfile = "$rrddir/$dsname$keyname-".$parts[1].".rrd";
	}
	$cmd = "$rrdtool update $rrdfile -t $dsnames $DATA";
	MySystem($cmd);
}
close(FD);

# Dump the former graph:
if ($sarstat ne "") {
	CreateImage();
}

sub CheckDate
{
	my ($date,$label) = @_;
	my @date;
	my $sec;
	my $month;

	@date = split(/[ :-]/,$date);
	$sec = timelocal($date[5],$date[4],$date[3],$date[1],$date[0]-1,$date[2]);
	#print "sec=$sec, startsec=$startsec, endsec=$endsec\n";
	if ($sec < $startsec) {
		$month = $startmonth+1;
		die("The $label date specified on the command line: $date, is anterior to the first date read in the file: $month-$startday-$startyear $starttime\n");
	}
	if ($sec > $endsec) {
		$month = $endmonth+1;
		die("The $label date specified on the command line: $date, is posterior to the last date read in the file: $month-$endday-$endyear $endtime\n");
	}

	return $sec;
}

sub Time24
{
	my ($parts) = @_;

	# Add 12 hours, but 12PM is 12 and 12AM is 00:
	#print "p0=",${$parts}[0],"--";
	my @thetime = split(/:/,${$parts}[0]);

	if (${$parts}[1] eq "AM") {
		if ($thetime[0] eq "12") { 
			${$parts}[0] = "00:".$thetime[1].":".$thetime[2]; 
		}
	}
	else {
		if ($thetime[0] ne "12") { 
			${$parts}[0] = $thetime[0]+12;
			${$parts}[0] .= ":".$thetime[1].":".$thetime[2]; 
		}
	}

	if ($verbose) { print "Time24: new time is: ",${$parts}[0],"\n"; }
}

sub MakeDSName
{
	my ($name) = @_;

	$name =~ s/%/prct_/g;
	$name =~ s/[^[:alnum:]]/_/g;

	return $name;
}

sub CreateImage 
{
	if ($skip) { return; }

	$title = $sarstats{$dsname}{'title'};
	$vlabel = $sarstats{$dsname}{'unit'};

	# $dsnames is col1:col2:....
	# we must apply $graph_col_sign and $graph_col_spec here:

	my @ds = split(/:/,$dsnames);
	my $defs = "";
	my $color;
	my $imgfile;
	COL: for ( my $idx = 0 ; $idx < scalar(@ds) ; $idx++ ) {
		if ($graph_name_spec ne "") {
			my $colname = $ds[$idx];
			if ($graph_col_sign eq "+") {
				# the column must be listed
				my $found = 0;
				foreach my $col (@graph_col_spec) {
					if ($col eq $colname) { 
						$found = 1;
						last;
					}
				}
				if (!$found) { next COL; }
			}
			else {
				# the column must not be listed
				foreach my $col (@graph_col_spec) {
					if ($col eq $colname) { 
						next COL;
					}
				}
			}
		}

		$color = $colors[$idx % scalar(@colors)];
		if ($ismultiple) {
			$defs .= "DEF:v$idx=RRDFILE:".$ds[$idx].":AVERAGE LINE$line_width:v$idx#$color:".$ds[$idx]." ";
		}
		else {
			$defs .= "DEF:v$idx=$rrdfile:".$ds[$idx].":AVERAGE LINE$line_width:v$idx#$color:".$ds[$idx]." ";
		}
	}

	if ($defs eq "") {
		die("No column selected to display the graph\n");
	}

	my $startdate = localtime($graph_startsec);
	my $enddate  = localtime($graph_endsec);
	if ($special_colon) {
		$startdate =~ s/:/\\:/g;
		$enddate =~ s/:/\\:/g;
	}
	#print $startdate,"\n";
	#print $enddate,"\n";
	my $legend = '"COMMENT:From '.$startdate.', To '.$enddate.'\\c" "COMMENT:\\n"';

	if ($ismultiple) {
		foreach $graphname (keys %graphs) {
			$imgfile = "$imgdir/$hostname-$dsname$keyname-$graphname.png";

			# set the good RRD file name:
			my $defs2 = $defs;
			$defs2 =~ s!RRDFILE!$rrddir/$dsname$keyname-$graphname.rrd!g;

			if ($keyname ne "") {
				my $keyname2 = substr($keyname,1); # suppress the leading '-'
				$title = $sarstats{$dsname}{'title'}{$keyname2}." for $graphname";
			}
			else {
				$title = $sarstats{$dsname}{'title'}." $graphname";
			}
			
			$cmd = "$rrdtool graph $imgfile -t '$title' -s $graph_startsec -e $graph_endsec $logarithmic -S $step -v '$vlabel' -w $imgwidth -h $imgheight -a PNG $legend $defs2 >/dev/null";
			MySystem($cmd);
		}
	}
	else {
		$imgfile = "$imgdir/$hostname-$dsname$keyname.png";

		$cmd = "$rrdtool graph $imgfile -t '$title' -s $graph_startsec -e $graph_endsec $logarithmic -S $step -v '$vlabel' -w $imgwidth -h $imgheight -a PNG $legend $defs >/dev/null";
		MySystem($cmd);
	}
}

sub MySystem
{
	my ($cmd) = @_;
	my $status;

	if ($verbose) { print $cmd,"\n"; }
	if ($status = system($cmd)) {
		die("Command '$cmd' failed with return code: $status\n");
	}
}

sub Usage
{
	print "Usage: $0\t[-?ov] [-d rrd_dir] [-i img_dir] [-W width] [-H height]\n";
	print "\t\t\t[-s start_date] [-e end_date] [-S step]\n";
	print "\t\t\t[-g graph_spec] [-t DMY|MDY] -f sar_file\n";
	print "Options:\n";
	print "\t-? : this help\n";
	print "\t-v : verbose mode\n";
	print "\t-o : use a logarithmic scale for Y scale\n";
	print "\t-d rrd_dir : directory where RRD files must be created\n";
	print "\t-i img_dir : directory where to place PNG images\n";
	print "\t-W width : images width (in pixels)\n";
	print "\t-H height : images height (in pixels)\n";
	print "\t-s start_date : start date (MM-DD-YYYY HH:MM:SS)\n";
	print "\t-e end_date : end date (MM-DD-YYYY HH:MM:SS)\n";
	print "\t-S step : interval (in seconds) between to values in the graph\n";
	print "\t-g graph_spec: by default all possible graphs are created\n";
	print "\t\tgraph_spec syntax is: data[:(+|-)column[,column...]]\n";
	print "\t\tthis creates only the graph and the specified columns\n";
	print "\t\tnote that graph and column name must contain '_' instead of '-'\n";
	print "\t-t MDY|DMY: indicates the format for the date displayed on the 1st output line\n";
	print "\t-f sar_file : file to analyse - create by the 'sar -f ...' command\n";

	exit(1);
}

exit(0);

# EOF