[ale] End of Time, *nix Time

[Bob Toxen]

The strange characters (on my screen they show as ?? but are for ASCII
hex escapes) appear due to the Micro$oft virus altering xtime's output
on the way to your posting.

I've just uploaded the new and improved code to my web site so please
download again and email just me (transam at VerySecureLinux.com) if you
get any more compiler warnings or strange results to be addressed.

This new version improves the messages to be less cryptinc but the
program does assume you know something about how time is handled in
*nix.  The short answer is that if you have the old signed 32-bit
time_t type then the largest year you will see will be 2038 in 
output of the form "Day-of-week Month Day ##:##:## Year".

Bob

On Sat, Apr 25, 2026 at 10:29:17AM -0700, Ron via Ale wrote:
> Bob Toxen via Ale wrote on 2026-04-24 19:43:
> > # Download this program: wget http://verysecurelinux.com/xtime.c #
> > Compile: make xtime # Run: ./xtime -q
> 
> I downloaded an compiled this.
> 
> Lots of warnings when running `make`, but it compiled.
> 
> What am I to make of the output? I can make no sense of it.
> 
> 
> $ ./xtime -q
> Copyright (c) Bob Toxen 2026.?? All rights reserved.
> 
> This program will analyze your *nix for the well-known bug if the
> seconds since 01/01/1970 exceeds a signed 32 bit (4-byte) integer.
> If it outputs abnormal output for years beyond 2038 then your computer
> will fail at that time, about 12 years from now.
> 
> Many *nix systems were fixed decades ago so that this variable became
> an unsigned 32-bit int, which can keep time until 2106.
> More recently most systems went to a signed 64-bit int.
> 
> Note that most Unix and Linux distributions corrected the time
> problem by approximately 2014 to work until 2106 (using an unsigned
> 32-bit number) or well beyond if using a 64-bit number but maybe the code
> will fail before the largest 64-bit signed (292,271,022,989 years)
> or unsigned number is exceeded.
> 
> 
> If it is not fixed in your version, well, good luck.
> 
> sizeof char=1, sizeof short=2, sizeof int=4, sizeof long=8, sizeof long
> long=8, sizeof time_t=8
> 
> Current years and seconds since the epoch: 56 1777137911
> ?? seconds/year:31536000, seconds/year including leap year:31557600, delta
> seconds:21600, delta hours:6
> 
> Biggest?? ??signed 4-byte long: years inc=?? ?? ?? ?? ?? ?? 0, years in the
> future=?? ?? ?? ?? ?? ??11, Mon Jan 18 19:14:07 2038
> Biggest unsigned 4-byte long: years inc=?? ?? ?? ?? ?? ?? 0, years in the
> future=?? ?? ?? ?? ?? ??79, Sat Feb?? 6 22:28:15 2106
> 
> Time: years inc=?? ?? ?? ?? ?? ?? 1, years in the future= ??2147437525, Wed
> Jun 12 15:25:11 2147483647
> 
> Welcome to the Restaurant at the end of the universe.?? Hello, your Majesty.
> 
> Biggest?? ??signed 8-byte long: years inc=?? ?? ?? ?? ?? ?? 0, years in the
> future= 292271022988,
> ERROR: Invalid seconds since Epoch in localtime
> Error code: Value too large for defined data type
> 
> Biggest unsigned 8-byte long: years inc=?? ?? ?? ?? ?? ?? 0, years in the
> future=?? ?? ?? ?? ?? -56, Wed Dec 31 15:59:59 1969
> 

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