egghelp.org community

[raider2k]

hi folks ^^

this time im looking for a way to catch errors that usually crash the eggy WITHOUT crashing it. ive seen this somewhere once, i tried it already with

[nml375]

That script is not quite properly written; I'd rather suggest something along these lines:

[raider2k]

both are just examples, aka the original code from that forum thread, of course i modified it to my needs

im wondering a bit about your examples - where is $scripts in foreach script $scripts coming from? and where is $::errorInfo coming from? im not able to follow the pointer from one to the other in that case, sorry :> (i see that $::errorInfo is also in the original thread, didnt pay much attention to it - is it some kind of global var?)

[raider2k]

[nml375]

First, your questions..

I placed my code in a proc I called "loadsafe", that takes one parameter (the list of scripts). So $scripts comes from the proc argument list..

Next, $::errorInfo:
This is a global variable (see the namespace operator :, that contains details regarding the latest error that occured. Since I use a full namespace path when accessing the variable, I don't have to use the global command.

Regarding your code, I would recommend that you do not build your list of scripts that way. You'll get away with it most of the times, but if your filenames contains characters such as { or }, you might be up for a nasty surprise (plus it's really bad coding practise that we see all too often).

Regarding your issues with the list command and using backslash (\), did you place a newline immediately after the backslash? It is solely used to escape the newline, so there cannot be any spaces or other characters between the \ and the newline.
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NML_375, idling at #eggdrop@IrcNET

[raider2k]

yup, this is true, figured where scripts comes from when i copied and modified it to my needs ^^

yup, namespace global var, got that, just wasnt really sure ^^

im wondering a bit whats so wrong about my code, having escapable character in FILENAMES isnt going to happen at all, i NEVER used and never will use special chars in a filename, is there anything i need to be aware of or is it only characters which need to be escape in case of?

[nml375]

The problem is that tcl lists are very delicate, while alot of coders/users think having one item per line automatically makes the string a list. The tcl interpreter will try it's best to parse the string as a list when using foreach, lindex, etc. but every now and then the string is too poorly formatted to make sense of.
In your case, you'll most likely get away with it, as I said in my previous post. But since this forum is alot about helping people code (better), I like to point out issues like these. If you get too comfortable with this "sloppy" (no offense) coding, it's very easy to start using them in cases where this really becomes an issue.

All this said, if it works for you, of course feel free to do it any way you feel comfortabe. I just wan't you to be aware of posible issues.
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NML_375, idling at #eggdrop@IrcNET

[raider2k]

ok, im always interested in becoming better, its just not clear enough to me what exactly i wasnt doing so properly.

is it about those " \ "'s ? if you dont mind please post me an example based on my code, i think that would help me out

btw: i also remember you telling me to use split $text before i lindex it in another post some time ago, still remember and also using it

[nml375]

The improper thing is that you are handling a string as if it was a list. You can craft strings that tcl manages to interpret as lists, though it still is a string. For trivial list elements, this is fairly easy, but simply adding a space into the element makes it non-trivial. If you're not careful, it'll catch you offguard, giving you a nice headache.. Or if you use this with a Windows-style filesystem (using \ instead of /}).

You can indeed use split to convert a string into a proper list, and using lindex on a string is technically the same improper issue. However, "split $text" would often be used when the content of $text comes from a remote user, where you have no control what-so-ever of it's original content (hence you cannot quarantee it to be a valid list structure).

Actually, that's quite a good example how "sloppy" coding might sneak up and stab you in the back.. You get comfortable using something like this:

[raider2k]

i think ... im confused right now

[nml375]

Ahh, sorry.
I guess the simplest way of putting it is this:
Whenever a command expects a parameter value to be a list, make sure you are providing a list - not a string.
The simplest way of creating a list, is either to use the list command - or to split a string into a list. If you try to handcraft lists, you're bound to run into trouble sooner or later.

Oh, and regarding the examples in the previous post:
The first example demonstrates an improper script where I 'get away' with it because my string resembles a list well enough for tcl to understand it.
The second extends the improper scripting by accepting 'untrusted data' as a list - and it appears to work in most cases. Except in some non-trivial cases, where the script all of a sudden seems to stop working.

Your script is similar to example 1 right now. The step to something like example 2 isn't that far away...
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NML_375, idling at #eggdrop@IrcNET

[raider2k]

mhm, i think now i know what you mean
very interesting, i hope ill keep that in mind
thx nml ^^

[user]

[nml375]

Nice catch, user. I'll update my post in a minute or so..
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NML_375, idling at #eggdrop@IrcNET

[raider2k]

W O N D E R F U L L

because right now i wanted to ask why its coming up with some errors here and there, i think missing uplevel was the answer to that not-yet-asked-question

thx again for help, thx to both of you

btw: since the loadsource proc does a list on script from foreach scripts, am i safe to use set scripts { .... } now? im still a bit confused regarding that as i want to put each script into its own line, starting from the very first line until the last one, "set scripts [list" into the line before the first and "]" into the line after the last one. doing this now results in an error telling me that bot doesnt understand command "scripts/reg.tcl"