Re: building rc on QNX4

[Gert-Jan Vons <vons@ocegr.fr>]

David Luyer <david_luyer@pacific.net.au> wrote:

>Basically some OS's (Digital Unix for one I think) have C libraries 
>which choke horribly if the size of the command line + environment array 
>is greater than a certain value, and if you have a number of complex
>functions in your shell this value (64k?) can be a pain.

For me "whatis |wc -c" returns 3308 bytes. However, I use a lot of lazy 
function loading, as has been talked about before on this list.

In my .rcrc, I have:

># Lazy function (un)loading.
>#
>fnlib = $home/bin/rcfuncs
>fn _ld { ~ $#* 1 && builtin . $fnlib/$1 }
>fn _unld { ~ $#* 1 && fn $1 { _ld $0 && $0 $* }}
>
># init all lazy functions by scanning the $fnlib directory
>name = () for ( name in `{builtin cd $fnlib ; ls} ) _unld $name

where my $home/bin/rcfuncs directory contains a number of files with rc 
function definitions (note that the file name must match the name of the 
function defined in it)

So until I actually use my rc functions, for a lot of them there's only 
"fn somefunc {_ld $0&&$0 $*}" in my environment, which gets expanded to 
the real function the first time I call somefunc.

And instead of re-reading my .rcrc file after every change to some 
function, I just do an "_unld newfunc", and the next time I call 
"newfunc", it is automatically reloaded from file.

If your functions are really big, you could even unload them 
automatically after use. But in that case, turning those functions into 
rc shell scripts is probably simpler...



         Gert-Jan
-----
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