I was looking for some standard symbols to represent the Control key and the Alt key, and couldn’t find one until I came across ISO/IEC 9995-7. 
Because I had much trouble finding a free copy of the document on the ’Net, I have made a table of the symbols and their functions below. I have marked those not present in Unicode as �.
Some examples: copy is usually [⎈ + C] and close is usually [⎇ + F4].
| Symbol |
Meaning/Summary |
| ⇧ |
Select level 2 (AKA Shift) |
| ⇫ |
Lock level 2 (AKA Shift-Lock) |
| ⇬ |
Caps lock |
| ⇭ |
Num lock |
| ⇮ |
Select level 3 |
| ⇯ |
Lock level 3 |
| ⇨ |
Group select |
| ⇰ |
Group lock |
| ␣ |
Space |
| ⍽ |
No-break space |
| ⎀ |
Insert |
| ⎁ |
Underline (continuous) |
| ⎂ |
Underline (discontinuous) |
| ⎃ |
Emphasize |
| ⎄ |
Compose characters |
| ⎅ |
Center |
| ⌫ |
Delete backwards |
| ␥ |
Delete |
| ⎚ |
Clear screen |
| ⇳ |
Scrolling (I assume this means Scroll lock) |
| � |
Help |
| ⎙ |
Print Screen |
| ⏎ |
Return |
| ⎆ |
Enter |
| ⎇ |
Alternate (Alt key) |
| ⎈ |
Control (Ctrl key) |
| ⎉ |
Pause |
| ⎊ |
Break/Interrupt |
| ⎋ |
Escape |
| ⎌ |
Undo |
| ↑ |
Cursor up |
| ↓ |
Cursor down |
| ← |
Cursor left |
| → |
Cursor right |
| ↟ |
Fast cursor up |
| ↡ |
Fast cursor down |
| ↞ |
Fast cursor left |
| ↠ |
Fast cursor right |
| ⇱ |
Home (Beginning) |
| ⇲ |
End |
| ⎗ |
Previous page |
| ⎘ |
Next page |
| ⇤ |
Tab left |
| ⇥ |
Tab right |
| � |
Line up |
| � |
Line down |
| � |
Backspace |
| � |
Partial line up |
| � |
Partial line down |
| � |
Partial space left |
| � |
Partial space right |
| � |
Set margin left |
| � |
Set margin right |
| � |
Release margin left |
| � |
Release margin right |
| � |
Release both margins |
| + |
Addition |
| − |
Subtraction |
| × |
Multiplication |
| ÷ |
Division |
| = |
Equals |
| ⎖ |
Decimal separator |
While Googling my way through the interwebs, I came across the 2008 Western Australian Certificate of Education sample examination for Stage 2 Biological Sciences. It contains this diagram:
If you’re wondering, the entire hierarchy is drawn from Umberto Eco’s novel Baudolino.
This is in reference to the current ‘Twitter image encoding challenge’ running on StackOverflow.
If we want to restrict ourselves to assigned, non-control, non-private Unicode characters, then by my reckoning that gives us 129,775 available characters.
wget http://unicode.org/Public/UNIDATA/UnicodeData.txt
awk -F ';' UnicodeData.txt -f countUnichars.awk | bc
countUnichars.awk source:
BEGIN { print "ibase=16" } # set bc to hex mode
$2 ~ /Private/ { # skip any lines with "private" in the description
getline;
}
n { # if n is set, then print the range for bc to calculate
printf("(%s-%s+1)+",$1,n);
n="";
}
$2 ~ /First>/ { # set n if the start of a range
n=$1;
getline;
}
$3 !~ "C." { # otherwise count anything that isn't some kind of a control character
i++;
}
END { # print out the count of everything else
printf("%X\n",i)
}This means we can store exactly 2377 bits (297 bytes) per message (this is 
), so if we use a 16-colour palette we can store about 594 pixels (
), which can almost reproduce the Mona Lisa thumbnail in the contest page.
I have wanted this for a while, and my brother linking me to this post was the last straw.
So here is a very quick and simple plugin; it simply puts a button on the toolbar that you can click when you want to stop playback after the current song. I based the toolbar button code on Alexandre Rosenfeld’s lastfm-queue plugin, since I had no idea where to start with that
Download it here, and put it into ~/.gnome2/rhythmbox/plugins/stop_after_song/. Activate it in Rhythmbox’s plugin dialog.
