NetNews Usenet Archive 1992 #31/NN_1992_31.iso/spool/comp/os/linux/22123

Text File | 1992-12-30 | 1.9 KB | 47 lines

Newsgroups: comp.os.linux
Path: sparky!uunet!think.com!spool.mu.edu!umn.edu!csus.edu!netcom.com!qualtrak
From: [e-mail] (Qual Trak)
Subject: Re: IMPORTANT [BUG in 0.99] Re: [ANNOUNCE]: linux version 0.99
Message-ID: <[e-mail]>
Organization: QualTrak Corporation
References: <[e-mail]> <[e-mail]> <[e-mail]>
Date: Wed, 30 Dec 1992 05:06:10 GMT
Lines: 36

In article <[e-mail]> [e-mail] (Mike Campbell ) writes:
>[e-mail] (Zdenek Radouch) writes:
>
>>Stephen Williams writes:
>
>>>Statics are either explicitly initialized or they are not.
>>>If they are not, their contents are UNDEFINED until set.
>>>This is per ANSI C.
>>>There is NO requirement of the compiler or system to zero
>>>un-initialized statics (or auto's).
>
>
>>I'll quote for you:
>
>>"A static object not explicitly initialized is initialized as if it
>>(or its members) were assigned the constant 0. The initial value of
>>an automatic object not explicitly initialized is undefined."
>
>
>You are correct - what would be the advantage of a static in a function?
>
>If you NEEDED to initialize it, you would lose the value of the variable
>every time the function was called, nullifying the advantage statics have
>in functions, (namely holding a value out of visibility).

You're correct up until the last two paragraphs - Although I can't
quote chapter and verse, maybe someone else will - a static variable
with an initializer is initialized exactly one time, which can be
considered to happen the first time the variable comes into scope.

I looked in k&r 2d ed and couldn't find reference to the above, but I've
seen it somewhere.
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John Birchfield - QualTrak Corp [phone] Home [phone]
[e-mail]
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