Checks if a ttf file (true type font) supports a given unicode codepoint (must be given as a 4 char hexa code, eg 2666 for BLACK DIAMOND SUIT)

check_codepoint.rb

#!/usr/bin/ruby

ttf=ARGV[0]
cp=ARGV[1].rjust(4,"0")
cp1="00"+cp[0..1]
cp2=cp[2..3]

s=%x{fc-query "#{ttf}"}
charset=s.scan(/charset: \n\t(.*?)\n[^\t]/m).flatten[0].split("\n\t")
row=charset.find{|r| r=~/^#{cp1}: /}
if row==nil then
  puts "not supported"
else
  num=cp2.to_i(16)
  section_index=num/32
  section=row.split(" ")[section_index+1]
  binary=section.split(//).map{|z| z.to_i(16).to_s(2).rjust(4,"0")}.join
  index=num % 32
  if binary[index]=="0" then 
   puts "not supported"
  else
   puts "supported"
  end
  
end