A neat discovery: on Debian and Red Hat, Perl is present by default and provides
Name.pl, a table of Unicode character codes and descriptions. Now you can quickly search for unicode characters by code or description, simply by grepping that file; this lets you use regexes, gives a compact overview, and is faster than going to a Unicode information websites. (But I’m glad those websites are there when my terminal font doesn’t display the character, for example.)
The grepping is just a one-liner:
grep -i 'some character' "$(locate Name.pl | head -1)". The link goes to a script in my dotfiles that passes the result through a Python script that parses the code and adds the character itself to the line.
$ unicode apl ⌶ 02336 APL FUNCTIONAL SYMBOL I-BEAM ⌷ 02337 APL FUNCTIONAL SYMBOL SQUISH QUAD ⌸ 02338 APL FUNCTIONAL SYMBOL QUAD EQUAL ⌹ 02339 APL FUNCTIONAL SYMBOL QUAD DIVIDE [...]