Linux basic commands -history

history command

Shell built-in command

history command to display a specified number of the instruction command, a read command history file directory to the history and the history command buffer command buffer write command in the file directory.

When the command is used alone, only the history display command, the command line, the symbol may be used !to perform the specified number of commands. For example, to execute the second command history, enter !2.

Command history is stored in memory when you exit or log shell, automatically save or read. In memory, history command only capable of storing 1000 history command, which is by the number of environment variables HISTSIZEto control.

grammar

history (Option) (parameters)

Options

- C: Clear the current command history;
 - A: The history command buffer write command in the command file history;
 - R & lt: the command history file command reads the current command history buffer;
 - W : the current command history write buffer command history command file.

parameter

n: n recent print commands.

Examples

Using the history command to display the 10 most recently used command history, enter the following command:

[root@localhost ~]# history 10
   92  ls
   93  cd ..
   94  ls
   95  exit
   96  ls -a
   97  cd .ssh/
   98  ls
   99  cat known_hosts
  100  exit
  101  history 10