Поиск определенного рубинового слова в txt-файле

Question

Я пытаюсь создать рубиновый инструмент, который проходит через файл, ищущий определенную строку, и если он находит это слово, чем сохраняет его в переменной. Если «НЕ», он печатает «слово не найдено» на консоли. Это возможно? Как я могу это кодировать?

Answer 1

Вы можете использовать метод File#open и метод readlines как это.

test.txt

This is a test string. 
Lorem imsum. 
Nope. 

код

def get_string_from_file(string, file_path) 
    File.open(file_path) do |f| 
    f.readlines.each { |line| return string if line.include?(string) } 
    end 
    nil 
end 

file_path = './test.txt' 
var = get_string_from_file('Lorem', file_path) 
puts var || "word not found" 
# => "Lorem" 

var = get_string_from_file('lorem', file_path) 
puts var || "word not found" 
# => "word not found" 

Я надеюсь, что эта гидропотенциала.

Answer 2

Вот несколько примеров того, как вы могли бы найти определенное слово в текстовом файле с помощью IO из ядра Ruby: http://ruby-doc.org/core-2.3.1/

В find_word_in_text_file.rb:

# SETUP 
# 
filename1 = 'file1.txt' 
filename2 = 'file2.txt' 

body1 = <<~EOS 
    PHRASES 

    beside the point 
    irrelevant. 

    case in point 
    an instance or example that illustrates what is being discussed: the “green revolution” in agriculture is a good case in point. 

    get the point 
    understand or accept the validity of someone's idea or argument: I get the point about not sending rejections. 

    make one's point 
    put across a proposition clearly and convincingly. 

    make a point of 
    make a special and noticeable effort to do (a specified thing): she made a point of taking a walk each day. 
EOS 

body2 = <<~EOS 
    nothing to see here 
    or here 
    or here 
EOS 

# write body to file 
File.open(filename1, 'w+') {|f| f.write(body1)} 

# write file without matching word 
File.open(filename2, 'w+') {|f| f.write(body2)} 

# METHODS 
# 
# 1) search entire file as one string 
def file_as_string_rx(filename, string) 

    # http://ruby-doc.org/core-2.3.1/Regexp.html#method-c-escape 
    # http://ruby-doc.org/core-2.3.1/Regexp.html#method-c-new 
    rx = Regexp.new(Regexp.escape(string), true) # => /whatevs/i 

    # read entire file to string 
    # http://ruby-doc.org/core-2.3.1/IO.html#method-i-read 
    text = IO.read(filename) 

    # search entire file for string; return first match 
    found_word = text[rx] 

    # print word or default string 
    puts found_word || "word not found" 
    # —OR— 
    #STDOUT.write found_word || "word not found" 
    #STDOUT.write "\n" 
end 

# 2) search line by line 
def line_by_line_rx(filename, string) 

    # http://ruby-doc.org/core-2.3.1/Regexp.html#method-c-escape 
    # http://ruby-doc.org/core-2.3.1/Regexp.html#method-c-new 
    rx = Regexp.new(Regexp.escape(string), true) # => /whatevs/i 

    # create array to store line numbers of matches 
    matches_array = [] 

    # search each line for string 
    # http://ruby-doc.org/core-2.3.1/IO.html#method-c-readlines 
    #lines = IO.readlines(filename) 
    # 
    # http://ruby-doc.org/core-2.3.1/Enumerable.html#method-i-each_with_index 
    # http://stackoverflow.com/a/5546681/1076207 
    # "Be wary of "slurping" files. That's when you 
    # read the entire file into memory at once. 
    # The problem is that it doesn't scale well. 
    #lines.each_with_index do |line,i| 
    # 
    # —OR— 
    # 
    # http://ruby-doc.org/core-2.3.1/IO.html#method-c-foreach 
    i = 1 
    IO.foreach(filename) do |line| 

    # add line number if match found within line 
    matches_array.push(i) if line[rx] 

    i += 1 
    end 

    # print array or default string 
    puts matches_array.any? ? matches_array.inspect : "word not found" 
    # —OR— 
    #STDOUT.write matches_array.any? ? matches_array.inspect : "word not found" 
    #STDOUT.write "\n" 
end 

# RUNNER 
# 
string = "point" 

puts "file_as_string_rx(#{filename1.inspect}, #{string.inspect})" 
file_as_string_rx(filename1, string) 

puts "\nfile_as_string_rx(#{filename2.inspect}, #{string.inspect})" 
file_as_string_rx(filename2, string) 

puts "\nline_by_line_rx(#{filename1.inspect}, #{string.inspect})" 
line_by_line_rx(filename1, string) 

puts "\nline_by_line_rx(#{filename2.inspect}, #{string.inspect})" 
line_by_line_rx(filename2, string) 

# CLEANUP 
# 
File.delete(filename1) 
File.delete(filename2) 

Командная строка:

 
$ ruby find_word_in_text_file.rb 
file_as_string_rx("file1.txt", "point") 
point 

file_as_string_rx("file2.txt", "point") 
word not found 

line_by_line_rx("file1.txt", "point") 
[3, 6, 7, 9, 10, 12, 15, 16] 

line_by_line_rx("file2.txt", "point") 
word not found