我在哪里可以找到有关“sudo !!”的文档 命令

Question

我刚刚了解到 Linux 有一个sudo !!命令，它实际上适用sudo于最后输入的命令。我从来没有听说过。

这是通用控件吗？我在哪里可以找到有关它的文档？

Answer 1

这只是 bash 的快捷方式。sudo!!顺便说一下，它不是。它是sudo !!（注意空格）。

的!!在bash基本上是前一命令的扩展。

看看 bash 手册页的“历史扩展”部分：

http://www.gnu.org/software/bash/manual/bashref.html#Event-Designators

Answer 2

它实际上sudo !!，它是由命令的sudo，与你可能熟悉，和事件标志，!!，这是指最后输入的命令。您可以在bash手册页的Event Designators部分下找到更多信息。

Event Designators
   An event designator is a reference to a command line entry in the  his?
   tory  list.   Unless  the reference is absolute, events are relative to
   the current position in the history list.

   !      Start a history substitution, except when followed by  a  blank,
          newline,  carriage return, = or ( (when the extglob shell option
          is enabled using the shopt builtin).
   !n     Refer to command line n.
   !-n    Refer to the current command minus n.
   !!     Refer to the previous command.  This is a synonym for `!-1'.
   !string
          Refer to the most recent command preceding the current  position
          in the history list starting with string.
   !?string[?]
          Refer to the most recent command preceding the current postition
          in the history list containing string.  The trailing  ?  may  be
          omitted if string is followed immediately by a newline.
   ^string1^string2^
          Quick  substitution.   Repeat  the  previous  command, replacing
          string1 with string2.  Equivalent  to  ``!!:s/string1/string2/''
          (see Modifiers below).
   !#     The entire command line typed so far.