[ale] End of Time, *nix Time

[Ron]

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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