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From: russotto@eng.umd.edu (Matthew T. Russotto)
Newsgroups: comp.sys.mac.programmer,aus.mac
Subject: Re: Danger Will Robinson, traps for young player.
Message-ID: <1990Aug20.143025.2160@eng.umd.edu>
Date: 20 Aug 90 14:30:25 GMT
References: <11591@wehi.dn.mu.oz>
Sender: news@eng.umd.edu (The News System)
Organization: College of Engineering, Maryversity of Uniland, College Park
Lines: 33

In article <11591@wehi.dn.mu.oz> JON@wehi.dn.mu.oz (Jon Eaves) writes:
>I want to extract the UserName from the Chooser. No problems, just use 
>tempHandle = GetString(CHOOSERNAME), then how do I get the "string" from
>the tempHandle.  The process I was using was
>	 strcpy(tempString,PtoCstr((char *)(*tempHandle));
>Great, this sets tempString correctly. BUT, the Chooser Name field gets
>mangled because the resource handle is now in 'C' string format.
>When the application exits, the resource map is saved and the System
>becomes unstable (Got the 'Cant Load the Finder', bomb !!)
>
>Now some questions.
>1) Why the hell is the handle to the resource attached to that resource?

You would have to ask an oldtimer@apple.com, but my guess would be MEMORY--
making copies each time you call GetString is expensive, especially in 128K.

>   Doesn't it make some sort of copy? At no stage do I explicitly use
>	ChangedResource(tempHandle);WriteResource(tempHandle);
>   Why is it saved then?

It may not be-- it may only be changed until you reboot-- remember that there
is only one resource handle for all applications that use the string.

>2) What is the best way to extract stuff from 'tempHandle' so that things
>   like that don't happen?  I presume there is a nice 'safe' way of doing
>   this.

strncpy(tempString,((char *)(*tempHandle)) + 1,
	 (size_t)(*(unsigned char *)(*tempHandle)));
tempString[*(unsigned char *)(*tempHandle)] = '\0';
--
Matthew T. Russotto	russotto@eng.umd.edu	russotto@wam.umd.edu
][, ][+, ///, ///+, //e, //c, IIGS, //c+ --- Any questions?