simple question about a char

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Originally Posted by citizen

>> A lot of people thing (sic) a string is just an array of char.

But a string is an array of char in C. Those people would be right.

Zeroing out memory can be done if you have a security concern, like cpjust suggests, and even then one could consider it a little overkill since RAM is not persistent memory.

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I wouldn't call it overkill. Other bugs in your program could allow hackers to read parts of memory that could contain sensitive data, or if your program does a core dump, the sensitive data could show up in the dump file.
Some customers at my company complained that some of our dump files contained user passwords in plain text.

Quote:

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Originally Posted by C_ntua

-So if the actual question is emptying an array of char then you should empty everything in the array (except if you want something more specific). As you would do if you wanted to empty an array of int.

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Except that you can't "empty" an array.

Perhaps an "empty" char array would be one that starts with 0?

I think we're talking about zeroing out every element in the array here.

I didn't read what (s)he was using the array for, thus I wasn't 100% sure. If you are doing string related stuff that is not a matter of system security, it is so much faster to just zero out the first char than to overwrite an entire array.

Why even zero out the first character if you don't have to? strcpy() works just as well on strings that already contain data. :)

You're right, though. It's more secure (if you care about that sort of thing) to zero every element in an array, but it's much easier and faster to zero only the first element. And despite what C_ntua may say, I think "\0xxx" is an empty string. ;)