使用Ruby来处理文本的教程

message = 'Heal the World…'

puts message

message1 = "Take home Rs #{100*3/2} "

puts message1

Output :

# ./string1.rb

# Heal the World…

# Take home Rs 150

irb>> str = >>EOF

irb>> "hello world

irb>> "how do you feel?

irb>> "how r u ?

irb>> EOF

"hello, world\nhow do you feel?\nhow r u?\n"

irb>> puts str

hello, world
how do you feel?
how r u?

irb>> str = "The world for a horse" # String initialized with a value

The world for a horse

irb>> str*2      # Multiplying with an integer returns a 
           # new string containing that many times
           # of the old string.

The world for a horseThe world for a horse

irb>> str + " Who said it ? "  # Concatenation of strings using the '+' operator

The world for a horse Who said it ?

irb>> str<<" is it? " # Concatenation using the '<<' operator

The world for a horse is it?

irb>> str[0] # The '[]' operator can be used to extract substrings, just 
      # like accessing entries in an array.
      # The index starts from 0.
84 # A single index returns the ascii value
      # of the character at that position

irb>> str[0,5] # a range can be specified as a pair. The first is the starting 
      # index , second is the length of the substring from the
      # starting index.

The w

irb>> str[16,5]="Ferrari" # The same '[]' operator can be used
         # to replace substrings in a string
         # by using the assignment like '[]='
irb>>str

The world for a Ferrari

Irb>> str[10..22] # The range can also be specified using [x1..x2] 

for a Ferrari

irb>> str[" Ferrari"]=" horse" # A substring can be specified to be replaced by a new
        # string. Ruby strings are intelligent enough to adjust the
        # size of the string to make up for the replacement string.

irb>> s

The world for a horse

irb>> s.split  # Split, splits the string based on the given delimiter
        # default is a whitespace, returning an array of strings.

["The", "world", "for", "a", "horse"]

irb>> s.each(' ') { |str| p str.chomp(' ') }

        # each , is a way of block processing the
   # string splitting it on a record separator
   # Here, I use chomp() to cut off the trailing space

"The"
"world"
"for"
"a"
"horse"

irb>> str = "hello, world"

hello, world

irb>> str.upcase

HELLO, WORLD

irb>>str   # str, remains as is.

Hello, world

irb>> str.upcase!  # here, str gets modified by the '!' at the end of 
        # upcase.
HELLO, WORLD

irb>> str

HELLO, WORLD

require 'csv'

writer = CSV.open('mycsvfile.csv','w')

begin

 print "Enter Contact Name: "

 name = STDIN.gets.chomp

 print "Enter Contact No: "

 num = STDIN.gets.chomp

 s = name+" "+num

 row1 = s.split

 writer << row1

 print "Do you want to add more ? (y/n): "

 ans = STDIN.gets.chomp

end while ans != "n"

writer.close

file = File.new('mycsvfile.csv')

lines = file.readlines

parsed = CSV.parse(lines.to_s)

p parsed

puts ""

puts "Details of Contacts stored are as follows..."

puts ""

puts "-------------------------------"

puts "Contact Name | Contact No"

puts "-------------------------------"

puts ""

CSV.open('mycsvfile.csv','r') do |row|

 puts row[0] + " | " + row[1] 

 puts ""
end

Enter Contact Name: Santhosh

Enter Contact No: 989898

Do you want to add more ? (y/n): y

Enter Contact Name: Sandy

Enter Contact No: 98988

Do you want to add more ? (y/n): n

Details of Contacts stored are as follows...

---------------------------------
Contact Name | Contact No
---------------------------------

Santhosh | 989898

Sandy | 98988

<cart id="userid">

<item code="item-id">

 <price>

 <price/unit>

 </price>

 <qty>

 <number-of-units>

 </qty>

</item>

</cart>

require 'rexml/document'

include REXML

file = File.new('shoppingcart.xml')

doc = Document.new(file)

root = doc.root

puts ""

puts "Hello, #{root.attributes['id']}, Find below the bill generated for your purchase..."

puts ""

sumtotal = 0

puts "-----------------------------------------------------------------------"

puts "Item\t\tQuantity\t\tPrice/unit\t\tTotal"

puts "-----------------------------------------------------------------------"

root.each_element('//item') { |item| 

code = item.attributes['code']

qty = item.elements["qty"].text.split(' ')

price = item.elements["price"].text.split(' ')

total = item.elements["price"].text.to_i * item.elements["qty"].text.to_i

puts "#[code]\t\t #{qty}\t\t   #{price}\t\t   #{total}"

puts ""

sumtotal += total

}

puts "-----------------------------------------------------------------------"

puts "\t\t\t\t\t\t  Sum total : " + sumtotal.to_s

puts "-----------------------------------------------------------------------"

Hello, santhosh, Find below the bill generated for your purchase...

-------------------------------------------------------------------------
Item   Quantity    Price/unit    Total
-------------------------------------------------------------------------
CS001    2       100      200

CS002    5       200      1000

CS003    3       500      1500

CS004    5       150      750

-------------------------------------------------------------------------
               Sum total : 3450
--------------------------------------------------------------------------

doc = Document.new

doc.add_element("cart1", {"id" => "user2"})

cart = doc.root.elements[1]

item = Element.new("item")

item.add_element("price")

item.elements["price"].text = "100"

item.add_element("qty")

item.elements["qty"].text = "4"

cart .elements << item

require 'rexml/document'

require 'rexml/streamlistener'

include REXML

class Listener

 include StreamListener

 def tag_start(name, attributes)

 puts "Start #{name}"

 end

 def tag_end(name)

 puts "End #{name}"

 end

end

listener = Listener.new

parser = Parsers::StreamParser.new(File.new("shoppingcart.xml"), listener)

parser.parse

Start cart

Start item

Start price

End price

Start qty

End qty

End item

Start item

Start price

End price

Start qty

End qty

End item

Start item

Start price

End price

Start qty

End qty

End item

Start item

Start price

End price

Start qty

End qty

End item

End cart