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Elixir交互式Shell: 2. 常用命令

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

原文 https://segmentfault.com/a/1190000004910720

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