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

!~ 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{
  #...
}