Open an arbitrary number of resources safely in ruby
I'm too lazy to work out what happens if I try
1 filenames.map {|f| File.open(f) }and the thirteenth file doesnt exist, but I bet I don't like it.
1 module Enumerable 2 # Example: 3 # ['a','b'].with_files {|f,g| ... } 4 # is the same as 5 # File.open('a') {|f| File.open('b') {|g| ... } } 6 # You can specify modes with 7 # [['a', 'rb'], ['b', 'w']].with_files ... 8 def with_files( 9 meth = File.method(:open), 10 offset=0, 11 inplace=false, 12 &block 13 ) 14 if inplace then 15 if offset >= length then 16 yield self 17 else 18 fname,mode = *self[offset] 19 File.open(fname,mode) {|f| 20 self[offset] = f 21 self.with_files(meth,offset+1,true,&block) 22 } 23 end 24 else 25 dup.with_files(meth,offset,true,&block) 26 end 27 end 28 end
