Date: Tue, 21 May 2002 13:05:35 +0300 (IDT)
From: Eli Zaretskii <eliz AT is DOT elta DOT co DOT il>
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To: Alex Vinokur <alexvn AT bigfoot DOT com>
cc: djgpp AT delorie DOT com
Subject: Re: mktime() & time_t
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On Tue, 21 May 2002, Alex Vinokur wrote:

> | > However : May mktime() return -1 ?
> |
> | It's in the docs: mktime returns -1 if you feed it with time outside the
> | range of dates it can represent.
> 
> But in this case mktime() returns UINT_MAX ( not  -1 ) because time_t if of 'unsigned int' type.

The bit patterns of UINT_MAX and -1 are exactly the same in DJGPP, so 
these are just two different names for the same value.

The reason the docs doesn't say UINT_MAX is that time_t can be signed on 
some platforms, unsigned on others.  Using -1 for comparison makes your 
programs more portable.  Especially since the C standard and Posix both 
say mktime should return -1 if it fails.

The same situation occurs with functions like `read' and `write', IIRC.