Something like this? Only handles a single request at a time, though.

#!/usr/bin/perl

use strict; # https://perlmonks.org/?node_id=11134663
use warnings;
use IO::Socket;
use IO::Select;

my $listen = IO::Socket::INET->new( LocalPort => 8080, # setup
  Listen => 256, Reuse => 1) or die $@;
my $sel = IO::Select->new($listen);

sub checkforrequests
  {
  for my $fh ( $sel->can_read(0) ) # 0 for poll
    {
    my $socket = $fh->accept;
    my $request = '';
    1 while sysread $socket, $request, 4096, length $request
      and not $request =~ /\n\r?\n/; # empty line test
    print $request =~ s/^/got HTTP packet: /gmr; # FIXME for testing
    # FIXME process request here
    print $socket "OK\n"; # FIXME sample response
    $request =~ /quit/ and die "exiting on 'quit'\n"; # FIXME for test
+ing
    }
  }

while( 1 ) # your loop as I understand it
  {
  select undef, undef, undef, 0.2; # FIXME your non-network stuff
  checkforrequests(); # this is added to your loop
  }
[download]

I used wget to talk to it, like this

wget -q -O - http://localhost:8080/CMD=changeplaylist
[download]

and I get an output of

got HTTP packet: GET /CMD=changeplaylist HTTP/1.1
got HTTP packet: User-Agent: Wget/1.21.1
got HTTP packet: Accept: */*
got HTTP packet: Accept-Encoding: identity
got HTTP packet: Host: localhost:8080
got HTTP packet: Connection: Keep-Alive
got HTTP packet:
[download]

A clever client could hang it if it tried. Should probably be done with a more extensive multi-connection handler, but they get bigger :)
( Which is why monks, including me, will suggest using an async package.)

Excellent... For my basic need, this works. Thanks!

For completeness (or overkill, if you prefer), here's a version with no blocking reads that can handle multiple clients with overlapped packets and only processes a packet when it is complete. It does that by using a hash to store partial data per connection until a complete packet arrives.

#!/usr/bin/perl

use strict; # https://perlmonks.org/?node_id=11134663
use warnings;
use IO::Socket;
use IO::Select;

my %data;
my $listen = IO::Socket::INET->new( LocalPort => 8080,
  Listen => 256, Reuse => 1) or die $@;
my $sel = IO::Select->new($listen);

sub checkforrequests
  {
  for my $fh ( $sel->can_read(0) ) # 0 for poll
    {
    if( $fh == $listen )
      {
      my $socket = $listen->accept;
      $data{$socket} = '';
      $sel->add( $socket );
      print "new client $socket\n";
      }
    elsif( sysread $fh, $data{$fh}, 4096, length $data{$fh} )
      {
      if( $data{$fh} =~ s/^(.*?\n\r?\n)//s ) # any whole HTTP commands
        {
        my $command = $1;
        print $command =~ s/^/got HTTP packet: /gmr;
        # FIXME process request here
        print $fh "OK\n"; # FIXME sample response
        shutdown $fh, 1;
        $command =~ /quit/ and die "exiting on 'quit' command\n";
        }
      }
    else
      {
      delete $data{$fh};
      $sel->remove( $fh );
      print "client left $fh\n";
      }
    }
  }

while( 1 ) # your loop as I understand it
  {
  select undef, undef, undef, 0.2; # FIXME your non-network stuff
  checkforrequests(); # this is added to your loop
  }
[download]

Mine is a little different

use strict; use warnings; 
  select (STDOUT); $| = 1; select(STDOUT);

# http://127.0.0.1/exit
# http://127.0.0.1/hi
# http://127.0.0.1/null
# http://127.0.0.1/unknown 

  use IO::Handle;
  use IO::Socket;
  use IO::Select;
  my $server = IO::Socket::INET->new( Proto     => 'tcp',
                                     PeerAddr  => "127.0.0.1",  # only
+ us  
                                     LocalPort => 80,
                                     Listen    => SOMAXCONN,
                                     Reuse     => 1);

  die "can't setup server on 80" unless $server;

  my $sel_read  = IO::Select->new();
  my $sel_write = IO::Select->new();
  my $sel_error = IO::Select->new();
  $sel_read-> add($server);

  my $cmdrun={}; 
  $cmdrun->{'/exit'}  =sub{exit;} ;
  $cmdrun->{'/hi'}    =sub{my $fh=shift; print $fh "\nhi\n";} ;
  $cmdrun->{'/null'}  =sub{} ;


  while(1) { 
    checkforrequests(); 
    } # superloop 

exit; 

sub checkforrequests { 
    my $timeout=1; 
    my ($rd_ptr,$wr_ptr,$er_ptr)=IO::Select->select($sel_read,undef,$s
+el_error,$timeout);
    for my $fh (@$rd_ptr) {
      if ($fh == $server) {
          my $client = $server->accept;
          $client->autoflush(1);
          $sel_read->add($client);
         } # server 
      else { 
          my $line=<$fh>; 
          print "line:$line";  
          my ($junk,$post)=split(' ',$line,3); 
          my $cmd=$cmdrun->{$post}; 
          if ($cmd) {&$cmd($fh);} 
          else {  print $fh "\n\nNO\n";  } 
          $sel_read->remove($fh);
          close $fh;
          } # client 
      } # for fh 
} # checkforrequests
[download]

Thanks Huck.

I was able to quickly adapt Tybalt89's suggestion in my code. I will give your suggestion a try as well.

Comparing and contrasting different solutions while learning is always helpful. Thanks again

They have a similar base

Mine does a two step between accept and read, a client CAN create the connection and wait a bit before writing, so mine wont block there. But in general http: clients shouldnt matter.

His has a better read, the way i commonly use it is a lot like his, but i just collect data, then have another loop that looks for completed lines so i dont block on the \n. IN both of these examples we block on the \n read, mine till \n, his to blank line.

I added a cmd lookup table for what to execute

I only look at the first line sent.

I added the /null command to show you what might happen if you dont send anything back

«…This is basic stuff…»

It isn’t. BTW and if it matters: Net::Curl::Simple is non-blocking:

«Net::Curl excells in asynchronous operations, thanks to a great design of libcurl(3). To take advantage of that power Net::Curl::Simple interface allways uses asynchronous mode. If you want a blocking request, you must either set callback to undef or call join() method right away.»