Ruby11 拾遗

Agenda

1. Loop
2. Expression
3. File Read/Write
4. Debug
5. Process & Thread

Loop

while

a = 10
while a > 0
  puts a
  a -= 1
end

until

a = 100

until a == 0
  puts a
  a -= 1
end

loop

a = 10

loop do
  break if a <= 0
  puts a
  a -= 1
end

循环控制

1. break
2. next

break

for x in 1..10
  break if x == 5
  puts x
end

next

for x in 1..10
  next if x == 6
  puts x
end

Expression

=~ 正则匹配 匹配到返回首字符匹配的位置，匹配不到返回nil

/hello/i =~ "hello world" # => 0

!~ 正则匹配 是否匹配不到 匹配到返回fals 匹配不到返回true

/666/i !~ "hello world" # => true

alias 别名

def hello
  'hello'
end

alias old_hello hello

def hello
  'new hello'
end

puts old_hello
puts hello

File Read/Write 文件读写

1. File.read
2. File.readlines
3. File#rewind etc
4. IO.read/write

File Read

file = File.open('run.log', 'r')
while line = file.gets
  puts line
end

File Write

file = File.open('run.log', 'a+')
file.puts 'hello'
file.close

File.open('run.log', 'a+') do |f|
  f.puts 'hello'
end

Debug

Debug 工具

1. ruby debugger
2. byebug

byebug

$ gem install byebug

require 'byebug'

def hello name
  byebug #此处会有断电，然后可以看上下文的变量
  puts name
end

hello 'world'

Process & Thread 进程和线程

Process

pid = Process.fork{
  #...
}

Thread

Thread.new{
  #...
}