Elixir交互式Shell: 2. 常用命令

Elixir交互式Shell: 1. 运行时系统标记
Elixir交互式Shell: 2. 常用命令
Elixir交互式Shell: 3. 创建本地和远程Shell
Elixir交互式Shell: 4. 处理文件和脚本
Elixir交互式Shell: 5. 配置IEx

这是IEx系列五部分中的第二部分, 在这一部分中, 我们将说明如何使用IEx中的命令

补全

在IEx中数输入Elixir, 让后按Tab键, 显示不全的结果

iex(60)> Elixir.
Access                    Agent                     Application               
ArgumentError             ArithmeticError           Atom                      
BadArityError             BadFunctionError          BadMapError               
BadStructError            Base                      Behaviour                 
Bitwise                   CaseClauseError           Code                      
Collectable               CompileError              CondClauseError           
Dict                      Elixir                    Enum                      
Enumerable                ErlangError               Exception                 
File                      Float                     FunctionClauseError       
GenEvent                  GenServer                 HashDict                  
HashSet                   IEx                       IO                        
Inspect                   Integer                   Kernel                    
KeyError                  Keyword                   List                      
Logger                    Macro                     Map                       
MapSet                    MatchError                Module                    
Node                      OptionParser              Path                      
Port                      Process                   Protocol                  
Range                     Record                    Regex                     
RuntimeError              Set                       Stream                    
String                    StringIO                  Supervisor                
SyntaxError               System                    SystemLimitError          
Task                      TokenMissingError         TryClauseError            
Tuple                     URI                       UndefinedFunctionError    
UnicodeConversionError    Version            

所有Enum模块中以字母m开头的函数

iex(60)> Enum.m
map/2           map_join/3      map_reduce/3    max/1           
max_by/2        member?/2       min/1           min_by/2        
min_max/1       min_max_by/2

帮助 (h/0, h/1)

通过h命令, 我们可以查看模块文档, 模块中函数的文档

h/0 显示IEx.Helpers文档
h/1 显示某个模块, 函数的文档

显示模块文档

iex(60)> h Enum     

显示函数文档

iex(62)> h Enum.reduce

文件和目录辅助功能

显示当前目录

iex(1)> pwd
/ElixirProjects/distributed/distro

列出当前目录中的文件和子目录, 和系统工具ls类似

iex(2)> ls
.editorconfig      .git               .gitignore         README.md          _build             
abc.sh             bcd.sh             config             def.sh             deps               
erl_crash.dump     lib                mix.exs            mix.lock           rel                
test

重启当前IEx Shell, 值编号变为(1)

iex(4)> respawn

Interactive Elixir (1.2.1) - press Ctrl+C to exit (type h() ENTER for help)
iex(1)> 

详细的命令列表可以直接在IEx Shell中键入h查看

iex(1)> h
...
  • b/1           - prints callbacks info and docs for a given module
  • c/2           - compiles a file at the given path
  • cd/1          - changes the current directory
  • clear/0       - clears the screen
  • flush/0       - flushes all messages sent to the shell
  • i/1           - prints information about the given data type
  • h/0           - prints this help message
  • h/1           - prints help for the given module, function or macro
  • import_file/1 - evaluates the given file in the shell's context
  • l/1           - loads the given module's beam code
  • ls/0          - lists the contents of the current directory
  • ls/1          - lists the contents of the specified directory
  • pid/3         — creates a PID with the 3 integer arguments passed
  • pwd/0         — prints the current working directory
  • r/1           — recompiles and reloads the given module's source file
  • respawn/0     — respawns the current shell
  • s/1           — prints spec information
  • t/1           — prints type information
  • v/0           — retrieves the last value from the history
  • v/1           — retrieves the nth value from the history
  • import_file/1 — evaluates the given file in the shell's context
...
iex(2)> 

访问前一个值

➜  iex
iex(1)> :os.timestamp
{1460, 298263, 550140}

iex(2)> v(-1)
{1460, 298263, 550140}

iex(3)> v(2)
{1460, 298263, 550140}

#iex:break

当输入错误, 无论如何也无法结束的时候输入 #iex:break结束当前行的输入, 而不必使用Ctrl + C结束IEx 会话.

可以试试下面的输入, 可以看到#iex:break的效果

iex(60)> list = [
...(60)> :a, "abc, :b]
...(60)> "
...(60)> ???
iex:63: warning: found ? followed by codepoint 0xA (newline), please use \n instead
...(60)> ;
iex:63: warning: found ? followed by codepoint 0xA (newline), please use \n instead
...(60)> .
iex:63: warning: found ? followed by codepoint 0xA (newline), please use \n instead
...(60)> #iex:break