ruby - Search and match string, only after a certain point in a file -

ruby - Search and match string, only after a certain point in a file -

how do scan file after finding particular line. first results not count. illustration (search 3s after finding line says "begin here"):

sample file 1 3 3 4 begin here 2 3 3 1 4

the expected output 2 3s

ruby's .. operator friend:

data.each_line |line| line.chomp! next unless (line =~ /^begin here$/) .. false puts line if line == '3' end __end__ 1 3 3 4 begin here 2 3 3 1 4

save file , run , you'll see:

3 3

.. (and much more obscure ...) come perl, , useful particular kind of use.

what happens .. two-state operator works if or unless first status line =~ /^begin here$/ in case. when status met, operator sticks, i.e., returns true until sec test matches, (returns true). 1 time happens, flip-flop starts returning false again.

in code, i'm fooling returning true, because sec test false. in other words, code reads end of data.

.. (and ...) really useful when you're scanning file, looking blocks of info occur throughout file. if sec conditional test found end of block, .. reset , code skip through file until found next block start, triggered, , started capturing again.

it's people haven't seen __end__ or data used. __end__ way tell ruby there no additional code executed beyond point. data internal file handle points lines next __end__ , can treated io , file objects. it's useful supplying info must have script, don't want set separate file. in case i'm pretending lines after __end__ separate file. easy-peasy.

ruby