Read a configuration file

From Rosetta Code
Revision as of 04:26, 11 February 2011 by rosettacode>Kernigh (Append a quick Ruby solution. Renamed variable 'needpeeling' to 'needspeeling' to match line 'NEEDSPEELING'.)
Read a configuration file is a draft programming task. It is not yet considered ready to be promoted as a complete task, for reasons that should be found in its talk page.

The task is to read a configuration file in standard configuration file, and set variables accordingly. For this task, we have a configuration file as follows:

# This is a configuration file in standard configuration file format
#
# Lines that begin with a hash symbol or semicolon are treated as
# comments and will be ignored

# This is the fullname parameter
FULLNAME Foo Barber

# This is a favourite fruit
FAVOURITEFRUIT banana

# This is a boolean that should be set
NEEDSPEELING

# This boolean is commented out
; SEEDSREMOVED


For the task we need to set four variables according to the configuration entries as follows:

  • fullname = Foo Barber
  • favouritefruit = banana
  • needspeeling = true
  • seedsremoved = false

Ruby

<lang ruby>fullname = favouritefruit = needspeeling = seedsremoved = false

open("fruit.conf", "r") do |file|

 file.each_line do |line|
   line.chomp!
   key, value = line.split(nil, 2)
   case key
   when /^([#;]|$)/; # ignore line
   when "FULLNAME"; fullname = value
   when "FAVOURITEFRUIT"; favouritefruit = value
   when "NEEDSPEELING"; needspeeling = true
   when "SEEDSREMOVED"; seedsremoved = true
   when /^./; puts "#{key}: unknown key"
   end
 end

end

puts "fullname = #{fullname}" puts "favouritefruit = #{favouritefruit}" puts "needspeeling = #{needspeeling}" puts "seedsremoved = #{seedsremoved}"</lang>