script does not fetch properly - linux

Question

#!/usr/bin/perl
if (! eval "require LWP::UserAgent;")
{
$ret = "LWP::UserAgent not found";
}
if ( exists $ARGV[0]) {
if ($ret)
{
print "no ($ret)\n";
exit 1;
}
my $ua = LWP::UserAgent->new(timeout => 5);
my $response = $ua->request(HTTP::Request->new('GET',$ARGV[0]));
my #content = split (/\n/, $response->content);
my $active_connections = -1;
if ($content[0] =~ /^Active connections:\s+(\d+)\s*$/i) {
$active_connections = $1;
}
my $accepts = -1;
my $handled = -1;
my $requests = -1;
if ($content[2] =~ /^\s+(\d+)\s+(\d+)\s+(\d+)\s*$/) {
$accepts = $1;
$handled = $2;
$requests = $3;
}
my $reading = -1;
my $writing = -1;
my $waiting = -1;
if ($content[3] =~ /Reading: (\d+) Writing: (\d+) Waiting: (\d+)\s*$/) {
$reading = $1;
$writing = $2;
$waiting = $3;
}
print "nginx_active:$active_connections nginx_reading:$reading nginx_writing:$writing nginx_waiting:$waiting ";
print "\n";
}
My nginx status page:
Active connections: 2
server accepts handled requests
2 2 2
Reading: 0 Writing: 1 Waiting: 1
running:
./get_nginx_clients_status.pl http://IP/nginx_status
nginx_active:-1 nginx_reading:-1 nginx_writing:-1 nginx_waiting:-1
I should be getting:
nginx_accepts:113869 nginx_handled:113869 nginx_requests:122594
Any idea what could be wrong?

Answer 1

Your code states:
my $accepts = -1;
my $handled = -1;
my $requests = -1;
And your output is:
nginx_active:-1 nginx_reading:-1 nginx_writing:-1 nginx_waiting:-1
Therefore, because you test:
$content[2] =~ /^\s+(\d+)\s+(\d+)\s+(\d+)\s*$/
... it follows that $content[2] does not contain the information your regular expression demands. Have you tried adding print $content[2] . "\n"; to help debug your script?
The Debugger
Please consider use of the Perl debugger. It will answer obvious problems very quickly for you.
Start your script using the -d flag. Then step through your code one line at a time using n to go to the next line, l to list the code at the current point, and x #content (for example) to list the contents of variables each step of the way.