Export formatted list of symbols defined in a C/C++ library

exportsym.rb

#!/usr/bin/env ruby

#==============================================================================
#
# Searches for a library either local or on the system and prints out a sorted
# list of all exported symbols found within it. (UNIX-like systems only)
#
# Useful for creating a wrapper/bindings for a C/C++ library.
#
# Example: exportsym tar
#   - Searches system for tar.so, tar.a, libtar.so, libtar.a, etc, etc.
#   - Outputs list of exported functions
#
#==============================================================================

lib = ARGV[0]
unless lib
  puts 'No library name specified'
  exit
end

SEARCH_PATHS = ['.', '/usr/lib', '/lib', '/var/lib']
EXTENSIONS = ['.so', '.a']

path = nil

SEARCH_PATHS.product(EXTENSIONS).each do |c|

  dir = c.first
  ext = c.last

  path = File.join(dir, lib + ext)
  break if File.exist?(path)

  unless /^lib/.match(lib)
    path = File.join(dir, 'lib' + lib + ext)
    break if File.exist?(path)
  end
  path = nil
end

if path.nil?
  puts "Unable to locate library \"#{lib}\""
  exit
end

result = `nm -D --defined-only '#{path}' -f bsd`
list = []
result.split("\n").map(&:chomp).each do |line|
    match = /^[\h]+ ([\w]) (.+)/.match(line)
    unless match
        warn("failed to match '${line}'")
        next
    end
    list << $2
end
list.sort!
list.each { |item| puts item }