start-memcached

memcached是一个高性能的分布式的内存对象缓存系统

#!/usr/bin/perl -w

# start-memcached
# 2003/2004 - Jay Bonci <[e-mail]>
# This script handles the parsing of the /etc/memcached.conf file
# and was originally created for the Debian distribution.
# Anyone may use this little script under the same terms as
# memcached itself.

use strict;

if($> != 0 and $< != 0)
{
	print STDERR "Only root wants to run start-memcached.\n";
	exit;
}

my $params; my $etchandle; my $etcfile = "/etc/memcached.conf";

# This script assumes that memcached is located at /usr/bin/memcached, and
# that the pidfile is writable at /var/run/memcached.pid

my $memcached = "/usr/bin/memcached";
my $pidfile = "/var/run/memcached.pid";

# If we don't get a valid logfile parameter in the /etc/memcached.conf file,
# we'll just throw away all of our in-daemon output. We need to re-tie it so
# that non-bash shells will not hang on logout. Thanks to Michael Renner for 
# the tip
my $fd_reopened = "/dev/null";

	sub handle_logfile
	{
		my ($logfile) = @_;
		$fd_reopened = $logfile;
	}

	sub reopen_logfile
	{
		my ($logfile) = @_;

		open *STDERR, ">>$logfile";
		open *STDOUT, ">>$logfile";
		open *STDIN, ">>/dev/null";
		$fd_reopened = $logfile;
	}

# This is set up in place here to support other non -[a-z] directives

my $conf_directives = {
	"logfile" => \&handle_logfile,
};

if(open $etchandle, $etcfile)
{
	foreach my $line (<$etchandle>)
	{
		$line ||= "";
		$line =~ s/\#.*//g;
		$line =~ s/\s+$//g;
		$line =~ s/^\s+//g;
		next unless $line;
		next if $line =~ /^\-[dh]/;

		if($line =~ /^[^\-]/)
		{
			my ($directive, $arg) = $line =~ /^(.*?)\s+(.*)/; 
			$conf_directives->{$directive}->($arg);
			next;
		}

		push @$params, $line;		
	}

}else{
	$params = [];
}

	push @$params, "-u root" unless(grep "-u", @$params);
	$params = join " ", @$params;

if(-e $pidfile)
{
	open PIDHANDLE, "$pidfile";
	my $localpid = <PIDHANDLE>;
	close PIDHANDLE;

	chomp $localpid;
	if(-d "/proc/$localpid")
	{
		print STDERR "memcached is already running.\n"; 
		exit;		
	}else{
		`rm -f $localpid`;
	}

}

my $pid = fork();

if($pid == 0)
{
		reopen_logfile($fd_reopened);
		exec "$memcached $params";
		exit(0);

}else{
	if(open PIDHANDLE,">$pidfile")
	{
		print PIDHANDLE $pid;
		close PIDHANDLE;
	}else{

		print STDERR "Can't write pidfile to $pidfile.\n";
	}
}