The Universe of Discourse

Sat, 25 Aug 2018

A software archaeology screwup

This week I switched from using the konsole terminal program to using gnome-terminal, because the former gets all sorts of font widths and heights wrong for high-bit characters like ⇒ and ③, making it very difficult to edit such text, and the latter, I discovered doesn't. Here's how konsole displays the text ☆☆★★★ “Good” as I move the cursor rightwards through it:

Uggggggh. Why did I put up with this bullshit for so long?

(I know, someone is going to write in and say the problem isn't in konsole, it's in the settings for the KooKooFont 3.7.1 package, and I can easily fix this by adding, removing, or adjusting the appropriate directives in /usr/share/config/fontk/config/fontulator-compat.d/04-spatulation, and… I don't care, gnome-terminal works and konsole doesn't.)

So I switched terminals, but this introduced a new problem: konsole would detect when a shell command had been run, and automatically retitle the tab it was run in, until the command exited. I didn't realize until this feature went away how much I had been depending on it to tell the tabs apart. Under gnome-terminal all the tabs just said Terminal.

Reaching back into my memory, to a time even before there were tabs, I recalled that there used to be a simple utility I could run on the command line to set a terminal title. I did remember xsetname, which sets the X window title, but I didn't want that in this case. I looked around through the manual and my bin directory and didn't find it, so I decided to write it fresh.

It's not hard. There's an escape sequence which, if received by the terminal, should cause it to retitle itself. If the terminal receives

    ESC ] 0 ; pyrzqxgl \cG

it will change its title to pyrzqxgl. (Spaces in the display above are for clarity only and should be ignored.)

It didn't take long to write the program:


from sys import argv, stderr

if len(argv) != 2:
    print("Usage: title 'new title'", file=stderr)

print("\033]0;{}\a".format(argv[1]), end="")

The only important part here is the last line. I named the program title, installed it in ~/bin, and began using it immediately.

A few minutes later I was looking for the tab that had an SSH session to the machine, and since the title was still Terminal, once I found it, I ran title plover, which worked. Then I stopped and frowned. I had not yet copied the program to Plover. What just happened?

Plover already had a ~/bin/title that I wrote no less than 14½ years ago:

   -rwxr-xr-x 1 mjd mjd 138 Feb 11  2004 /home/mjd/bin/title

Here it is:


my $title = join " ", @ARGV;
$title = qx{hostname -s || hostname} if $title eq "";
chomp $title;
print "\e]0;$title\cG";

Why didn't I find that before I wrote the other one?

The old program is better-written too. Instead of wasting code to print a usage message if I didn't use it right, I had spent that code in having it do something useful instead.

This is not the first time I have done something like this.

Oh well, at least I can reacquire the better UI now that I know about it.

[ Addendum 20220127: I did it again ]

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