[hlcoders] Examples of uses for IEngine->ServerInsertCommand()

2005-06-09 Thread Mattie Casper


As promised, this email contains examples of the sorts of things that plugin
authors cannot manage in Source without some method to insert commands at the
beginning of the server command queue. This ability is vital for any plugin
wishing to create meta console commands. I.e. commands like alias, exec,
incrementvar, etc.

Variable expansion --

 EventScripts makes extensive use of variable expansion for its console
commands, and it's crippled without InsertCommand(). There's no way to arrange
for expanded commands to execute right away before the rest of a config file.
For example, let's say I added the following lines to a .cfg file (e.g.
server.cfg):

// server.cfg
// let's say 'mypluginvar' is a variable exposed by my plugin
mypluginvar "ClanMatch"
expandvars echo *** mypluginvar equals %mypluginvar%
echo *** The above line should say "mypluginvar equals ClanMatch"
echo *** server.cfg is completely done. should see nothing else.
// end server.cfg

So, if my plugin's 'expandvars' command expanded variables in the string
provided to it and then passed it back to the server, the only mechanism it can
use is ServerCommand(). This will place it AFTER everything else in the queue.
As such, the output would be:

*** The above line should say "mypluginvar equals ClanMatch"
*** server.cfg is completely done. should see nothing else.
*** mypluginvar equals ClanMatch

This is definitely not what someone writing a .cfg file would be expecting. They
expect the commands to go in order of writing. EventScripts supports a great
deal of variable expansion, but there's no support for intuitive ordering. This
example is trivial compared to the complicated scripts people are creating. It
really weakens the plugin when admins can't trust that your variables will be
expanded properly in relation to other commands in the cfg file.
-

Conditional expressions --
-
 EventScripts supports conditional expressions. These are also hindered without
InsertCommand(). The order of execution again gets all out of phase. For
example, let's say I added the following lines to a .cfg file (e.g. server.cfg):

// server.cfg
// let's say my plugin exposes an "exec_if" command
exec_if sv_gravity > 800 then reset_grav.cfg
echo *** sv_gravity was set back to 800 by increase_grav.cfg
exec_if sv_gravity > 800 then something_wrong.cfg
// end of server.cfg

In this case, the plugin command "exec_if" would test the condition "sv_gravity
> 800" and then use, sadly, ServerCommand() to place "exec reset_grav.cfg" in
the queue where it could reset the gravity back to 800. Unfortunately, this goes
to the very end of the queue, so the rest of the server.cfg executes first. This
means the second conditional will STILL see sv_gravity incorrectly because it
goes through the server command queue like this:

1. exec_if
2. echo
3. exec_if
4. exec reset_grav.cfg
5. exec something_wrong.cfg

#5 should never happen-- and #4 should happen before the 'echo' does. Yet we
can't do this because InsertCommand() isn't yet available to plugin writers.
-

Loops --
--
 EventScripts does not yet support loops, but these would also be possible if
Valve provided a way to insert commands at the beginning of the queue. Without
it, you cannot be certain that the loop lines will execute before the next line
in a script.
--

Enhanced versions of alias, exec, etc
-
EventScripts doesn't do this yet, but if I wanted to create an enhanced version
of these Valve commands, the new commands will always be deficient without
InsertCommand(). For example, if we wanted to write an optimized "exec" command
that cached the .cfg file in memory on the first execution and then always ran
it from memory whenever called (to avoid refetches from disk):

// server.cfg
memexec only_changes_on_reboot.cfg
exec load_plugins.cfg
// end of server.cfg

In this case, simulating "exec" is impossible if I wish to maintain the order of
a .cfg file. I.e., we can't cycle through the lines of the file and have them
inserted at the beginning of the command queue like Valve does. This means that
anytime we try to add the lines, they'll always fall *after* every other line in
the .cfg file. Order is important at times for plugins and the like, and without
that we just can't improve upon the console commands very well.
-


Anyway, I'm going to stop now because this is getting so long that I'm sure no
one will read it. ;) Rest assured that all of these things and more would be
possible if Valve enhanced the Source SDK to include a mechanism for adding
commands to the beginning of the queue.

Anyone curious about using EventScripts, you can find my forums here:
http://www.sourcemod.net/forums/viewforum.php?f=20

Thanks for reading this far. Maybe it will give other coders some ideas, too,
-Mattie


___

Re: [hlcoders] Examples of uses for IEngine->ServerInsertCommand()

2005-06-10 Thread Jeremy Swigart
Have you considered using a scripting language such as lua or
gamemonkeyscript or another one that supports fake threading?
Specifically you might be interested in their ability to execute over
many frames, yet still be written in a top down manner. Here's an
example of GMS, which I use in my bot.

/ server.cfg
if(sv_gravity > 800)
{
exec("reset_grav.cfg");
echo("gravity reset");
yield(); // suspend execution of the script till the next frame, can
also do sleep() commands
}
else
{
echo("gravity is fine");
}
echo("this happens the frame after the gravity is reset, or right away
if the exec didnt happen");

Everything you do and much more would be possible using the features
of an existing scripting language, and with it you'd get the power of
conditionals, tables, loops, and much more.

Just an idea.

J

On 6/9/05, Mattie Casper <[EMAIL PROTECTED]> wrote:
>
> As promised, this email contains examples of the sorts of things that plugin
> authors cannot manage in Source without some method to insert commands at the
> beginning of the server command queue. This ability is vital for any plugin
> wishing to create meta console commands. I.e. commands like alias, exec,
> incrementvar, etc.
>
> Variable expansion --
> 
>   EventScripts makes extensive use of variable expansion for its console
> commands, and it's crippled without InsertCommand(). There's no way to arrange
> for expanded commands to execute right away before the rest of a config file.
> For example, let's say I added the following lines to a .cfg file (e.g.
> server.cfg):
>
> // server.cfg
> // let's say 'mypluginvar' is a variable exposed by my plugin
> mypluginvar "ClanMatch"
> expandvars echo *** mypluginvar equals %mypluginvar%
> echo *** The above line should say "mypluginvar equals ClanMatch"
> echo *** server.cfg is completely done. should see nothing else.
> // end server.cfg
>
> So, if my plugin's 'expandvars' command expanded variables in the string
> provided to it and then passed it back to the server, the only mechanism it 
> can
> use is ServerCommand(). This will place it AFTER everything else in the queue.
> As such, the output would be:
>
> *** The above line should say "mypluginvar equals ClanMatch"
> *** server.cfg is completely done. should see nothing else.
> *** mypluginvar equals ClanMatch
>
> This is definitely not what someone writing a .cfg file would be expecting. 
> They
> expect the commands to go in order of writing. EventScripts supports a great
> deal of variable expansion, but there's no support for intuitive ordering. 
> This
> example is trivial compared to the complicated scripts people are creating. It
> really weakens the plugin when admins can't trust that your variables will be
> expanded properly in relation to other commands in the cfg file.
> -
>
> Conditional expressions --
> -
>   EventScripts supports conditional expressions. These are also hindered 
> without
> InsertCommand(). The order of execution again gets all out of phase. For
> example, let's say I added the following lines to a .cfg file (e.g. 
> server.cfg):
>
> // server.cfg
> // let's say my plugin exposes an "exec_if" command
> exec_if sv_gravity > 800 then reset_grav.cfg
> echo *** sv_gravity was set back to 800 by increase_grav.cfg
> exec_if sv_gravity > 800 then something_wrong.cfg
> // end of server.cfg
>
> In this case, the plugin command "exec_if" would test the condition 
> "sv_gravity
>  > 800" and then use, sadly, ServerCommand() to place "exec reset_grav.cfg" in
> the queue where it could reset the gravity back to 800. Unfortunately, this 
> goes
> to the very end of the queue, so the rest of the server.cfg executes first. 
> This
> means the second conditional will STILL see sv_gravity incorrectly because it
> goes through the server command queue like this:
>
> 1. exec_if
> 2. echo
> 3. exec_if
> 4. exec reset_grav.cfg
> 5. exec something_wrong.cfg
>
> #5 should never happen-- and #4 should happen before the 'echo' does. Yet we
> can't do this because InsertCommand() isn't yet available to plugin writers.
> -
>
> Loops --
> --
>   EventScripts does not yet support loops, but these would also be possible if
> Valve provided a way to insert commands at the beginning of the queue. Without
> it, you cannot be certain that the loop lines will execute before the next 
> line
> in a script.
> --
>
> Enhanced versions of alias, exec, etc
> -
>  EventScripts doesn't do this yet, but if I wanted to create an enhanced 
> version
> of these Valve commands, the new commands will always be deficient without
> InsertCommand(). For example, if we wanted to write an optimized "exec" 
> command
> that cached the .cfg file in memory on the first execution and then always ran
> it from memory whenever called (to avoid refetches from disk):

Re: [hlcoders] Examples of uses for IEngine->ServerInsertCommand()

2005-06-10 Thread Mattie Casper

Thanks for the suggestion, but, as you may have guessed, this has been
considered. ;)  Yet, creating an entire scripting engine isn't the goal of
EventScripts. There are lots of different scripting engines out there, and they
definitely have their place for administrators who understand coding.
EventScripts is trying to be the middle-ground between a structured/scoped
language and the console commands they know and love. As I mentioned below, ES
doesn't yet support looping and the like and may never do so--- it's not
intended to be a full-powered scripting language.

With EventScripts, we're trying to enhance the console commands so that even
everyday normal console/rcon commands and normal autoexec.cfg/server.cfg files
can take advantage of very simple logic and variable expansion. We don't need
everything a scripting language can do, we just want some basic enhancements to
the command console. Most of these console enhancements would be along the lines
Valve was already been moving, e.g. with "setinfo" and "incrementvar".

Yet, even in the case of a full blown scripting language, not having
InsertCommand() means that any scripts/commands that you wished to invoke via a
normal Valve cfg file would have the same ordering problem if they needed to
pass commands back to the server (e.g. exec, changelevel, kickid, etc). These
commands would execute *after* the current .cfg file was totally resolved and
not in-place. This wouldn't be intuitive and would likely cause problems! It
wouldn't be a problem if you didn't allow the console to launch scripts, but the
server console is a great place for invoking things like that (especially
remotely).

*** TO CLARIFY, this isn't a problem just for scripting engines! *** It's a
problem for ANY PLUGIN that uses console commands and needs to interact with the
console. Let's say I wrote a console command "mattie_exec" that took Con_Argv(1)
and passed it to exec with a different directory prefix (e.g. my mod's
directory).

// server.cfg
mattie_exec blah.cfg
exec load_plugins.cfg
// end of server.cfg

Now, the mattie_exec command, all it does is call engine->ServerCommand("exec
matties_mod\blah.cfg\n"). In this case, the console would execute like this:

1. (contents of server.cfg added to the queue around LevelInit())
2. mattie_exec runs (places "exec mattie_mod\blah.cfg" at end of queue)
3. exec load_plugins.cfg runs (all plugins activated, configured, etc)
4. exec mattie_mod\blah.cfg runs

You see that even though the mattie_exec command was placed in a certain order
in the cfg file, it's irrelevant. Any server commands those commands rely upon
cannot be activated until after the entire .cfg file has been processed. This
means that if the "load_plugins.cfg" relied upon any settings created in
blah.cfg, there's no way at all to get it to work short of bypassing the plugin
commands.

Admittedly, this is a simple example, but it underscores the issue outside of a
scripting context. Plugin console commands could be calling back to any number
of other console commands. We all have access to ServerCommand(), right? Well,
just like Valve, we need it's sister command in order to create proper console
commands. Sometimes we don't care about ordering, so ServerCommand() might be
appropriate, but many times ordering *will* be important. We truly need
ServerInsertCommand(), and I hope everyone can see that.

Thanks for your help and for reading this far,
-Mattie

----- Original Message -
From: "Jeremy Swigart" <[EMAIL PROTECTED]>
To: 
Sent: Friday, June 10, 2005 7:17 AM
Subject: Re: [hlcoders] Examples of uses for IEngine->ServerInsertCommand()



Have you considered using a scripting language such as lua or
gamemonkeyscript or another one that supports fake threading?
Specifically you might be interested in their ability to execute over
many frames, yet still be written in a top down manner. Here's an
example of GMS, which I use in my bot.

/ server.cfg
if(sv_gravity > 800)
{
exec("reset_grav.cfg");
echo("gravity reset");
yield(); // suspend execution of the script till the next frame, can
also do sleep() commands
}
else
{
echo("gravity is fine");
}
echo("this happens the frame after the gravity is reset, or right away
if the exec didnt happen");

Everything you do and much more would be possible using the features
of an existing scripting language, and with it you'd get the power of
conditionals, tables, loops, and much more.

Just an idea.

J

On 6/9/05, Mattie Casper <[EMAIL PROTECTED]> wrote:


As promised, this email contains examples of the sorts of things that plugin
authors cannot manage in Source without some method to insert commands at the
beginning of the server command queue. This ability is vital for any plugin
wishing to create meta cons

Re: [hlcoders] Examples of uses for IEngine->ServerInsertCommand()

2005-06-10 Thread Jeremy Swigart
I could be wrong, but even if ServerInsertCommand() puts the script
command at the front of the queue as opposed to the back, that still
wouldn't be executed until the current script is finished. Sounds like
really what you need is ServerCommandNow() that executes it right now,
so that when the next line of the current script runs, it can be sure
that the results of the script it just invoked is already done. Sounds
like even with ServerInsertCommand() it is gonna be a pain to get the
ordering right.

On 6/10/05, Mattie Casper <[EMAIL PROTECTED]> wrote:
> Thanks for the suggestion, but, as you may have guessed, this has been
> considered. ;)  Yet, creating an entire scripting engine isn't the goal of
> EventScripts. There are lots of different scripting engines out there, and 
> they
> definitely have their place for administrators who understand coding.
> EventScripts is trying to be the middle-ground between a structured/scoped
> language and the console commands they know and love. As I mentioned below, ES
> doesn't yet support looping and the like and may never do so--- it's not
> intended to be a full-powered scripting language.
>
> With EventScripts, we're trying to enhance the console commands so that even
> everyday normal console/rcon commands and normal autoexec.cfg/server.cfg files
> can take advantage of very simple logic and variable expansion. We don't need
> everything a scripting language can do, we just want some basic enhancements 
> to
> the command console. Most of these console enhancements would be along the 
> lines
> Valve was already been moving, e.g. with "setinfo" and "incrementvar".
>
> Yet, even in the case of a full blown scripting language, not having
> InsertCommand() means that any scripts/commands that you wished to invoke via 
> a
> normal Valve cfg file would have the same ordering problem if they needed to
> pass commands back to the server (e.g. exec, changelevel, kickid, etc). These
> commands would execute *after* the current .cfg file was totally resolved and
> not in-place. This wouldn't be intuitive and would likely cause problems! It
> wouldn't be a problem if you didn't allow the console to launch scripts, but 
> the
> server console is a great place for invoking things like that (especially
> remotely).
>
> *** TO CLARIFY, this isn't a problem just for scripting engines! *** It's a
> problem for ANY PLUGIN that uses console commands and needs to interact with 
> the
> console. Let's say I wrote a console command "mattie_exec" that took 
> Con_Argv(1)
> and passed it to exec with a different directory prefix (e.g. my mod's
> directory).
>
> // server.cfg
> mattie_exec blah.cfg
> exec load_plugins.cfg
> // end of server.cfg
>
> Now, the mattie_exec command, all it does is call engine->ServerCommand("exec
> matties_mod\blah.cfg\n"). In this case, the console would execute like this:
>
> 1. (contents of server.cfg added to the queue around LevelInit())
> 2. mattie_exec runs (places "exec mattie_mod\blah.cfg" at end of queue)
> 3. exec load_plugins.cfg runs (all plugins activated, configured, etc)
> 4. exec mattie_mod\blah.cfg runs
>
> You see that even though the mattie_exec command was placed in a certain order
> in the cfg file, it's irrelevant. Any server commands those commands rely upon
> cannot be activated until after the entire .cfg file has been processed. This
> means that if the "load_plugins.cfg" relied upon any settings created in
> blah.cfg, there's no way at all to get it to work short of bypassing the 
> plugin
> commands.
>
> Admittedly, this is a simple example, but it underscores the issue outside of 
> a
> scripting context. Plugin console commands could be calling back to any number
> of other console commands. We all have access to ServerCommand(), right? Well,
> just like Valve, we need it's sister command in order to create proper console
> commands. Sometimes we don't care about ordering, so ServerCommand() might be
> appropriate, but many times ordering *will* be important. We truly need
> ServerInsertCommand(), and I hope everyone can see that.
>
> Thanks for your help and for reading this far,
> -Mattie
>
> - Original Message -
> From: "Jeremy Swigart" <[EMAIL PROTECTED]>
> To: 
> Sent: Friday, June 10, 2005 7:17 AM
> Subject: Re: [hlcoders] Examples of uses for IEngine->ServerInsertCommand()
>
>
> > Have you considered using a scripting language such as lua or
> > gamemonkeyscript or another one that supports fake threading?
> > Specifically you might be interested in their ability to execute over
> >

RE: [hlcoders] Examples of uses for IEngine->ServerInsertCommand()

2005-06-11 Thread Karl \"XP-Cagey\" Patrick
> Yet, even in the case of a full blown scripting language, not having
> InsertCommand() means that any scripts/commands that you wished to
> invoke via a normal Valve cfg file would have the same ordering problem if

> they needed to pass commands back to the server (e.g. exec, changelevel,
> kickid, etc).

One solution to your problem that doesn't require an API change is
instructing users to write a one-line config file that simply calls your
plugin-enabled parser to run on another file.  E.g. have the entire contents
of autoexec.cfg be "eventscripts_exec autoexec_script.cfg\n".  Once you have
that arrangement, there aren't any commands that you need to preempt from
the top level scripts--load and manipulate the entire autoexec_script.cfg
file in memory to perform whatever transforms you need, then feed the entire
transformed file to the server in a block.  Delayed insertion removes the
need for preemptive insertion, and as far as your end users know or care,
they're still using Valve's config system.

Placement of the entire config into a one-off file isn't seamless, but it's
not hard for users to understand and it doesn't require much extra work or
drive space.  If HL2 calls two script files, say autoexec.cfg and
server.cfg, at nearly the same time and they both contain a single call into
a one-off, the execution order will appear to be the same to end users even
if the second exec comes before or in the middle of the interpreted commands
from the first file, since the effect of calling the second file would place
its commands after the complete set of commands from the intial file
(assuming the whole file interpret-and-stuff mechanism described above and
synchronous server command execution).

You really don't need out-of-order placement for variable substitution or
subscript execution using this scheme--you could even support calls into
other files and process them entirely in place before you begin inserting
the top level file. You might want to have preemptive insertion for live
evaluation of loop conditions, but that problem can also be solved through
delayed insertion - keep all commands after the evaluation statement in
memory until you get back your result. Simple loop counters can be unrolled
in place instantly, and I'm not sure how much complexity a configuration
script really needs.

My 2 cents,

Karl


> -Original Message-
> From: [EMAIL PROTECTED] [mailto:hlcoders-
> [EMAIL PROTECTED] On Behalf Of Jeremy Swigart
> Sent: Friday, June 10, 2005 6:20 AM
> To: hlcoders@list.valvesoftware.com
> Subject: Re: [hlcoders] Examples of uses for IEngine-
> >ServerInsertCommand()
>
> I could be wrong, but even if ServerInsertCommand() puts the script
> command at the front of the queue as opposed to the back, that still
> wouldn't be executed until the current script is finished. Sounds like
> really what you need is ServerCommandNow() that executes it right now,
> so that when the next line of the current script runs, it can be sure
> that the results of the script it just invoked is already done. Sounds
> like even with ServerInsertCommand() it is gonna be a pain to get the
> ordering right.
>
> On 6/10/05, Mattie Casper <[EMAIL PROTECTED]> wrote:
> > Thanks for the suggestion, but, as you may have guessed, this has been
> > considered. ;)  Yet, creating an entire scripting engine isn't the goal
> of
> > EventScripts. There are lots of different scripting engines out there,
> and they
> > definitely have their place for administrators who understand coding.
> > EventScripts is trying to be the middle-ground between a
> structured/scoped
> > language and the console commands they know and love. As I mentioned
> below, ES
> > doesn't yet support looping and the like and may never do so--- it's not
> > intended to be a full-powered scripting language.
> >
> > With EventScripts, we're trying to enhance the console commands so that
> even
> > everyday normal console/rcon commands and normal autoexec.cfg/server.cfg
> files
> > can take advantage of very simple logic and variable expansion. We don't
> need
> > everything a scripting language can do, we just want some basic
> enhancements to
> > the command console. Most of these console enhancements would be along
> the lines
> > Valve was already been moving, e.g. with "setinfo" and "incrementvar".
> >
> > Yet, even in the case of a full blown scripting language, not having
> > InsertCommand() means that any scripts/commands that you wished to
> invoke via a
> > normal Valve cfg file would have the same ordering problem if they
> needed to
> > pass commands back to the server (e.g. exec, changelevel, kicki

Re: [hlcoders] Examples of uses for IEngine->ServerInsertCommand()

2005-06-11 Thread Mattie Casper

This is also something I've considered-- I was just discussing this in my forum.
Obviously writing my own 'exec' (and a lot of surrounding overhead) is a way I
can achieve what I want without Valve providing the appropriate mechanism.

It's not terrible to force all users to use a different .cfg file system, but
it's certainly not the idea behind EventScripts, or really what other plugin
authors might need. Other plugin authors trying to write commands that order
properly won't find very good ROI on rewriting an exec (they just have to live
with it). EventScripts itself is supposed to just extend the console with a
bunch of new commands -- we'd all prefer if it didn't require admins to change
how they're doing things today if they want them to work. Even if they did so
(as you say, I suspect a lot of users could live with it), all it takes is for
them to forget and add lines to the traditional .cfg files (which a lot of
rental sites provide web access to, edit-wise) and things get out of order
again.

Also keep in mind that people also use aliases to stack commands in groups into
the command buffer. I don't have a lot of recourse in those situations other
than providing my own 'alias' handler in the script preprocessor and disallowing
use of the conventional one if the user wishes things to order properly.

Anyway, it's certainly doable if my user base is comfortable with changing their
current paradigm and I reinvent the wheel a few times, but that's definitely
quite far out of line with what EventScripts was supposed to be. I.e. I just
want to add powerful console commands that should work fine in any server.cfg,
autoexec.cfg. I know I have to move 'out of that realm' if Valve's not able to
provide the InsertCommand() API, but that won't solve the problem for any plugin
but my own (unless they also re-invent the wheel to solve this).

All in all, I have options, and I appreciate the suggestions (keep 'em coming,
by all means!), but mostly my available options involve circumventing Valve and
creating my own independent engine. I'd, of course, much rather work with them
and interoperate. And to do so, I need this one easy and accessible command and
it will open a world of possibility for console commands.

On the platforms where EventScripts works best, already administrators are able
to recreate a huge number of plugins simply using .cfg files and some popular
admin plugins. See this thread for examples:
http://www.sourcemod.net/forums/viewtopic.php?t=898

Thanks again for your suggestions,
-Mattie


- Original Message -
From: "Karl "XP-Cagey" Patrick" <[EMAIL PROTECTED]>
To: 
Sent: Saturday, June 11, 2005 8:58 AM
Subject: RE: [hlcoders] Examples of uses for IEngine->ServerInsertCommand()



Yet, even in the case of a full blown scripting language, not having
InsertCommand() means that any scripts/commands that you wished to
invoke via a normal Valve cfg file would have the same ordering problem if



they needed to pass commands back to the server (e.g. exec, changelevel,
kickid, etc).


One solution to your problem that doesn't require an API change is
instructing users to write a one-line config file that simply calls your
plugin-enabled parser to run on another file.  E.g. have the entire contents
of autoexec.cfg be "eventscripts_exec autoexec_script.cfg\n".  Once you have
that arrangement, there aren't any commands that you need to preempt from
the top level scripts--load and manipulate the entire autoexec_script.cfg
file in memory to perform whatever transforms you need, then feed the entire
transformed file to the server in a block.  Delayed insertion removes the
need for preemptive insertion, and as far as your end users know or care,
they're still using Valve's config system.

Placement of the entire config into a one-off file isn't seamless, but it's
not hard for users to understand and it doesn't require much extra work or
drive space.  If HL2 calls two script files, say autoexec.cfg and
server.cfg, at nearly the same time and they both contain a single call into
a one-off, the execution order will appear to be the same to end users even
if the second exec comes before or in the middle of the interpreted commands
from the first file, since the effect of calling the second file would place
its commands after the complete set of commands from the intial file
(assuming the whole file interpret-and-stuff mechanism described above and
synchronous server command execution).

You really don't need out-of-order placement for variable substitution or
subscript execution using this scheme--you could even support calls into
other files and process them entirely in place before you begin inserting
the top level file. You might want to have preemptive insertion for live
evaluation of loop conditions, but that problem can 

Re: [hlcoders] Examples of uses for IEngine->ServerInsertCommand()

2005-06-11 Thread Mattie Casper

I'm pretty sure the command queue works the same as most of these games since
Quake. All 'exec' does is place all of the lines into the command queue in the
proper order. Then the command handler will take each command independently off
of the queue. At that point, they're not a 'block' or anything, they're just
individual commands that happen to be placed in the queue in a sequence. When
any individual command is processed, it can still insert commands at the front
of the queue and have it execute before the (former) next command is scheduled
to do so. This is almost certainly why an 'exec' or 'alias' within a cfg file
happens before continuing with other lines in the .cfg file-- they pretty much
always insert their looked-up lines into the front of the queue (these built-in
commands are basically a limited form of 'variable expansion' already). In order
to create other commands that can behave the same way, we need something like
ServerInsertCommand() rather than one that adds to the end of the queue.

So in short, I'm 95% certain that this command is exactly what the community
would need for this purpose.
-Mattie

- Original Message -
From: "Jeremy Swigart" <[EMAIL PROTECTED]>
To: 
Sent: Friday, June 10, 2005 9:20 AM
Subject: Re: [hlcoders] Examples of uses for IEngine->ServerInsertCommand()



I could be wrong, but even if ServerInsertCommand() puts the script
command at the front of the queue as opposed to the back, that still
wouldn't be executed until the current script is finished. Sounds like
really what you need is ServerCommandNow() that executes it right now,
so that when the next line of the current script runs, it can be sure
that the results of the script it just invoked is already done. Sounds
like even with ServerInsertCommand() it is gonna be a pain to get the
ordering right.

On 6/10/05, Mattie Casper <[EMAIL PROTECTED]> wrote:

Thanks for the suggestion, but, as you may have guessed, this has been
considered. ;)  Yet, creating an entire scripting engine isn't the goal of
EventScripts. There are lots of different scripting engines out there, and
they
definitely have their place for administrators who understand coding.
EventScripts is trying to be the middle-ground between a structured/scoped
language and the console commands they know and love. As I mentioned below,
ES
doesn't yet support looping and the like and may never do so--- it's not
intended to be a full-powered scripting language.

With EventScripts, we're trying to enhance the console commands so that even
everyday normal console/rcon commands and normal autoexec.cfg/server.cfg
files
can take advantage of very simple logic and variable expansion. We don't need
everything a scripting language can do, we just want some basic enhancements
to
the command console. Most of these console enhancements would be along the
lines
Valve was already been moving, e.g. with "setinfo" and "incrementvar".

Yet, even in the case of a full blown scripting language, not having
InsertCommand() means that any scripts/commands that you wished to invoke via
a
normal Valve cfg file would have the same ordering problem if they needed to
pass commands back to the server (e.g. exec, changelevel, kickid, etc). These
commands would execute *after* the current .cfg file was totally resolved and
not in-place. This wouldn't be intuitive and would likely cause problems! It
wouldn't be a problem if you didn't allow the console to launch scripts, but
the
server console is a great place for invoking things like that (especially
remotely).

*** TO CLARIFY, this isn't a problem just for scripting engines! *** It's a
problem for ANY PLUGIN that uses console commands and needs to interact with
the
console. Let's say I wrote a console command "mattie_exec" that took
Con_Argv(1)
and passed it to exec with a different directory prefix (e.g. my mod's
directory).

// server.cfg
mattie_exec blah.cfg
exec load_plugins.cfg
// end of server.cfg

Now, the mattie_exec command, all it does is call engine->ServerCommand("exec
matties_mod\blah.cfg\n"). In this case, the console would execute like this:

1. (contents of server.cfg added to the queue around LevelInit())
2. mattie_exec runs (places "exec mattie_mod\blah.cfg" at end of queue)
3. exec load_plugins.cfg runs (all plugins activated, configured, etc)
4. exec mattie_mod\blah.cfg runs

You see that even though the mattie_exec command was placed in a certain
order
in the cfg file, it's irrelevant. Any server commands those commands rely
upon
cannot be activated until after the entire .cfg file has been processed. This
means that if the "load_plugins.cfg" relied upon any settings created in
blah.cfg, there's no way at all to get it to work short of bypassing the
plugin
commands.

Admittedl