3. Self-learning Linux road: Shell feature three: command history

Command history

Summary: Bash holds a list of commands that have been executed in the past.

The command process for the current shell is saved in memory.

When you exit, save the hidden folder to the current User folder. Bash_histroy, ls-a can view

　　

History Shortcuts:

!#: #为命令历史列表中的命令编号 (#history: View the history and number of commands in the cache)

!: Executes the previous one, equivalent to the direction key

!-1: Perform the first countdown command

!string: The last command in the execution history that starts with string

History-c: Emptying the command history in the cache

history-d #: Delete section # command

HISTORY-A: Append to Buffer

　　arguments referencing the previous command :

!$ or shortcut ESC release and press.

　　

Environment Variables for command history

Histsize:

echo $HISTSIZE: View the value of a variable-"1000

Histfile:

echo $HISTFILE:/root/.bash_history

Histfilesize:

echo $HISTFILESIZE: 1000

Histcontrol: Controlling the generation of command history

Echo $HISTCONTROL

1. Ignoredups: Ignore consecutive and repetitive commands

2. Ignorespace: The command to start the space is ignored

3. Ignoreboth: Merging on two functions

To modify the value of the Histcontrol, just run the assignment statement.

　　

　　　　

3. Self-learning Linux road: Shell feature three: command history