Simon Tatham / is on Nostr

Free software developer and hobby mathematician.

Author and lead developer of #PuTTY, and "Simon Tatham's Portable Puzzle Collection", a set of one-player puzzle games running on many platforms. Also various smaller or less well known things.

Web site: https://www.chiark.greenend.org.uk/~sgtatham/

Last Notes

2024-07-07 09:16:27

A piece of "motivational CSS" that I sometimes include in web pages I haven't finished writing yet:
.FIXME {
background: rgb(160,0,0);
color: rgb(0,255,0);
font-weight: bold;
font-family: "Comic Sans MS";
}
That way, when I write something like
<span class="FIXME">come back and add a link to xyz</span>
in the body text, I'm _really_ motivated to make that horrible thing go away.

2024-07-06 13:49:41

Have nothing in your home that you do not
● know to be useful
● believe to be beautiful
● feel unaccountable vague fondness for
● can imagine a hypothetical situation in which you'd *really* need it
● firmly intend to get round to doing something with one of these days
● can't remove because of all the other junk piled on top of it
● feel guilty about not dealing with something more important first
● fear throwing away in case you remember tomorrow why you bought it
● miscellaneous

2024-06-17 15:06:57

Everyone's tired of the standard test values you make up by writing English words in hex, like 0xDEADBEEF, or 0xDEFACED, or 0xC0FFEE.
But if you're writing in C or C++, you can get a few slightly less familiar ones by making use of the U, L, UL, LL or ULL suffixes on integer literals. 0xBA5EBALL, 0xDAFF0D1L, 0xDECE17FUL.
Or maybe you think those are still boring? Then just stick with 0xDULL.

2024-06-13 12:33:56

- reply

for that I use a tiny utility I wrote called 'reservoir', which reads and buffers input until EOF, then writes it all out again. With the -o option, you can tell it a file to overwrite. So you can do this kind of thing, without depending on your filter tool having an option that works like sed -i:
$arbitrary_filtering_command < filename | reservoir -o filename
https://www.chiark.greenend.org.uk/~sgtatham/utils/
https://www.chiark.greenend.org.uk/~sgtatham/utils/reservoir.html

2024-06-10 10:34:08

'mkdir -p' lets you make a deeply nested subdirectory like a/b/c/d, making all the intermediate directories on the way to it. So if even 'a' doesn't exist, it'll make that, then a/b, etc.
But you can also get it to make multiple _non_-nested directories, because it accepts '..' in the path and doesn't treat it specially:
$ mkdir -p alpha/../beta/../gamma
$ ls
alpha beta gamma
$

2024-05-28 09:41:36

- reply

yes! The last time I tried *really violently* to get into a DVD case (as it turned out, because of a security device the shop had forgotten to remove), I destroyed the disc completely.
That time, the film was 'Pirates of the Caribbean'. So I'll always remember it as the day I _almost_ watched Jack Sparrow.

2024-05-28 08:34:57

My Blu-ray of Dune Part 2 was delivered. The polythene wrapping on the case was rather tight, so I had to use the point of a knife to get into it.
I thought that approach lacked artistry, but I didn't let that stop me.

2024-05-22 10:06:59

Who was the most privileged member of the Beatles?
Ring 0.
#GeekJoke

2024-04-25 16:12:29

In bash, writing ${var?} instead of just ${var} or $var means if var isn't defined then bash will throw an error and _not_ execute your command, instead of expanding it to "" and carrying on.
mv file1 file2 $subdir # oops, I overwrote file2
mv file1 file2 ${subdir?} # error message instead of disaster
My favourite use of this is for example commands in documentation, with placeholders for the user to fill in. Then it's OK if a user accidentally copy-pastes it _without_ filling them in!

2024-04-25 16:12:29

2024-04-15 19:20:58

We've released #PuTTY version 0.81. This is a SECURITY UPDATE, fixing a #vulnerability in ECDSA signing for #SSH.
If you've used a 521-bit ECDSA key (ecdsa-sha2-nistp521) with any previous version of PuTTY, consider it compromised! Generate a new key pair, and remove the old public key from authorized_keys files.
Other key types are not affected, even other sizes of ECDSA. In particular, Ed25519 is fine.
This vulnerability has id CVE-2024-31497. Full information is at https://www.chiark.greenend.org.uk/~sgtatham/putty/wishlist/vuln-p521-bias.html