Chisel是facebook開源的輔助xcode進行iOS開發(fā)調試的工具，包含一系列更加有用的lldb命令，而且Chisel還支持添加本地以及自定義命令。本文從工具介紹開始，帶大家認識并使用這一強大工具。

Chisel 簡介

github地址

安裝

直接按照官方文檔進行：

1. 安裝Homebrew

ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"

2. 安裝Chisel

brew update
brew install chisel

3. 更新.lldbinit
   .lldbinit文件是lldb啟動之前加載的文件，用于lldb的初始化，每次lldb啟動都會加載。安裝chisel成功之后，終端會打印如下提示，按照提示，將啟動chisel的命令復制到.lldbinit文件中。

   
   
   chisel安裝.png
   
   

   我是通過如下命令直接將上面的命令寫入文件中(>>表示追加到文件尾，如果你已經添加過則無需再次添加)

echo command script import /usr/local/opt/chisel/libexec/fblldb.py >> ~/.lldbinit

4. 重啟xcode并check
   check方法有兩種，第一種是打開終端依次輸入：llbd<enter>,help<enter>；第二種方法是打開xcode，打斷點并執(zhí)行到斷點處，輸入help命令。滾動help的結果，當找到Current user-defined commands:一行，即表示安裝成功。

   
   
   chisel安裝check.png

Chisel常用命令簡介

• pmethods
  print the class and instance methods of a class.

• pclass
  Print the inheritance starting from an instance of any class.

• poobjc
  Print the expression result, with the expression run in an ObjC++ context. (Shortcut for "expression -O -l ObjC++ -- " ).

• pviews
  Print the recursion description of <aView>.

• pcells
  Print the visible cells of the highest table view in the hierarchy.

• pblock
  Print the block`s implementation address and signature.

• mask
  Add a transparent rectangle to the window to reveal a possibly obscured or hidden view or layer's bounds

• border
  Draws a border around <viewOrLayer>. Color and width can be optionally provided. Additionally depth can be provided in order to recursively border subviews.

• show
  Show a view or layer.

添加本地及自定義命令

參考官方文檔，這里整理出基本步驟如下：

1. 開發(fā)命令腳本
   官方文檔提供了一個example（源碼貼在下面方便大家閱讀）
2. 更新.lldbinit
   同Chisel安裝完成后的步驟一樣，需要將初始化的命令同步到.lldbinit文件中。
3. check命令
   同check Chisel是否安裝成功的方法一樣。

#!/usr/bin/python
# Example file with custom commands, located at /magical/commands/example.py

import lldb
import fblldbbase as fb

def lldbcommands():
  return [ PrintKeyWindowLevel() ]
  
class PrintKeyWindowLevel(fb.FBCommand):
  def name(self):
    return 'pkeywinlevel'
    
  def description(self):
    return 'An incredibly contrived command that prints the window level of the key window.'
    
  def run(self, arguments, options):
    # It's a good habit to explicitly cast the type of all return
    # values and arguments. LLDB can't always find them on its own.
    lldb.debugger.HandleCommand('p (CGFloat)[(id)[(id)[UIApplication sharedApplication] keyWindow] windowLevel]')

最后，Enjoy yourself！