Converting file to string and replacing string text with user input

Question

I need to replace placeholders NOUN, VERB, ADJ, and ADV in a file solution09.txt with user input.

Madlib solution09.txt:

One day I was watching my son [ADV] play with his [NOUN]. He was pretending the [NOUN] were [ADJ]. After a few minutes he was pretending to [VERB], because one of the [NOUN] drove away. When i asked him about it he [ADV] said, umm it's funny when [NOUN] [VERB] because [NOUN] can't really [VERB].

I think I successfully put the file into a string, but I have to read the string, and replace the placeholders with user input. Once I replace, I need to output the new madlib. I'm getting the user input into variables, but I'm not sure how to correctly replace the placeholder with the users input.

Current code:

file = File.open("solution09.txt", "r")
contents = file.read
puts "Enter a noun: "
noun = gets.chomp

puts "Enter a verb: "
verb = gets.chomp

puts "Enter an adjective: "
adj = gets.chomp

puts "Enter an adverb: "
adv = gets.chomp

if file.include?('NOUN')
  file1= file.gsub("[NOUN]", noun, "[VERB]", verb, "ADJ", adj, "ADV", adv)
end

First issue I see would be that gsub doesn't quite work like that. If you want to do multiple substitutions, then you need to make multiple calls to gsub, like `new_string = old_string.gsub('[NOUN]', noun).gsub('[VERB]', verb)` You can string as many gsubs as you want like that. Second issue is that you're inconsistent with your [] surrounding the parts of speech. NOUN and VERB have them, ADJ and ADV don't. Third issue is that you're calling gsub on `file`, which is the file object, rather than `contents`, which is a string that represents your data. That should be enough to get started. — Some Guy, Jun 06 '16 at 02:40
That is exactly what I needed to get it to output correctly. Thank you! — Nate_LADE, Jun 06 '16 at 02:46

score 1 · Answer 1 · answered Jun 06 '16 at 05:16

You can also build a replacement hash:

filename = "solution09.txt"
contents = File.read(filename)
replacements = {}

puts "Enter a noun: "
replacements['[NOUN]'] = gets.chomp

puts "Enter a verb: "
replacements['[VERB]'] = gets.chomp

puts "Enter an adjective: "
replacements['[ADJ]'] = gets.chomp

puts "Enter an adverb: "
replacements['[ADV]'] = gets.chomp

And pass it to gsub:

contents.gsub(Regexp.union(replacements.keys), replacements)

Regexp.union creates a pattern that matches any of the given keys.

score 0 · Accepted Answer · edited May 23 '17 at 11:58

Your code should look like

filename = "solution09.txt"
contents=File.read(filename)

puts "Enter a noun: "
noun=gets.chomp

puts "Enter a verb: "
verb=gets.chomp

puts "Enter an adjective: "
adj=gets.chomp

puts "Enter an adverb: "
adv=gets.chomp

if contents.include?('NOUN')
  { "\[NOUN\]" => noun,
    "\[VERB\]" => verb,
    "\[ADJ\]" => adj,
    "\[ADV\]" => adv
  }.each do |key, value|
    contents.gsub!(key, value)
  end
  File.open(filename, "w") { |f| f << contents }
end

You need separate operation for read and write. There are other ways to do this

You can see how to do with single file pointer https://stackoverflow.com/a/10173112/1380263

You can also use ruby methods which interact with shell and use sed command (system, backticks, peopen)

Really depends on what suits your situation the best

There are so many ways to code to get the same results. This is another example of how every one has their own way of coding. — Nate_LADE, Jun 06 '16 at 03:23

sawa · Answer 3 · 2016-06-06T05:25:22.887

0

file = File.read("solution09.txt")
.gsub(/\[(NOUN|VERB|ADJ|ADV)\]/) do
  part = case $1
  when "NOUN" then "a noun"
  when "VERB" then "a verb"
  when "ADJ" then "an adjective"
  when "ADV" then "an adverb"
  end
  puts "Enter #{part}: "
  gets.chomp
end

edited Jun 06 '16 at 05:25

answered Jun 06 '16 at 03:09

sawa

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This is a great way to shorten up my code. Thank you for providing your solution! – Nate_LADE Jun 06 '16 at 03:24
1

This is not equivalent to the OPs code. It will prompt for every single replacement. (BTW, your `case` statement is missing an `end`) – Stefan Jun 06 '16 at 05:08
1

@Stefan Thanks for pointing out. I realized that it was not the same, but I wasn't sure about the OP's intention. – sawa Jun 06 '16 at 05:26

Converting file to string and replacing string text with user input

3 Answers3