Some of the basic features of bash on Linux:

Command Completion : tab

The shell program receives a request from the user to execute the command, and when the analysis is complete, the leftmost string is treated as a command

command lookup mechanism :

To find internal commands :

according to directory set in PATH environment variable, from left to right, search for file name under directory

The given heading character, if it can uniquely identify a command file program, directly complements the

given a heading character, if a command file program cannot be uniquely identified , thelist is given at a time tab

Path Completion : Tab

Under the given starting path, match each file in the path with the start string under the corresponding path.

if it can be uniquely identified, the direct completion

Otherwise, tab again , give the list

Double click Tab:

/2tab Show All directories below the root directory, including hidden directories

./2tab current directory subdirectories, including hidden directories

*2tab current directory subdirectories, excluding hidden directories

~2tab List of all users

$2tab All variables

@2tab/etc/hosts Record (CentOS7 not supported)

=2tab equivalent to ls –A (CentOS7 not supported)

mkdir: Create a new directory

Mkdir-p: automatically create parent directories on Demand

-V: Show detailed procedures

-M: directly given permissions

Note : The path base name is the action object of the command, and the path before the base name must exist

RmDir: Deleting a directory

Rmdir-p: When a directory is deleted, if its parent directory is empty, it is deleted

-V: Display procedure

Command line expansion :

~: automatically expands to the user's home directory, or the specified user's home directory

{}: Can host a comma-delimited list of paths and be able to expand multiple paths

For example:/tmp/{a,b} is equivalent to /tmp/a/tmp/b

execution status result of the command :

Bash outputs secondary results with status return values

Success : 0

failed : 1-255

after the command execution completes, its status return value is saved in bash 's special variable $? in

References :

Strong quote : '

Weak reference : ""

Command Reference : '

Bash shortcut keys :

Ctrl + L clear screen, equivalent to clear command

Ctrl + C abort command

Ctrl + S lock screen

Ctrl + q unlock

Ctrl + a cursor moves to the beginning of the command, which is equivalent to Home

Ctrl + e cursor moves to the end of the command line, equivalent to end

Ctrl + u Delete from cursor to beginning of command

Ctrl + k Remove from cursor to end of command line

CP Command : Copy

single Source copy : CP [OPTION] ... [-T] SOURCE DEST

if DEST does not exist : The file is created in advance and the data stream of the source file is copied to DEST

if DEST exists :

if DEST file : Overwrite destination file

if DEST Directory file : first Create a file with the same name as the source file in the DEST directory and copy its data stream

Multi-source replication : CP [OPTION] ... SOURCE ... DIRECTORY

if DEST does not exist : Error

if DEST exists :

if DEST Non-directory file : Error

if DEST is a directory file : Copy each file to the directory separately and keep the original

CP [OPTION] ...-t DIRECTORY SOURCE ...

Common Options :

-I: interactive replication, that is, before overwriting to remind users to confirm

-F: force overwrite target file

-r: Recursive copy directory

Historical: command-line history

command history is typically recorded in a . bash_history file, with the default record of

The history in the current shell is recorded in memory and will only be saved in . Bash_history after exiting.

-C: empty command History

-D Offset: Delete the specified offset command in history

N: Show recent nth history

-A: append the newly executed command history list to the history file for this session

-N: read unread rows to History list in history file

-r: read History file attached to History list

-W: Save History list to specified history file

-P: expands the history parameter into multiple lines, but does not exist in the history list

-S: expands the history parameter into a row, appended to the history list

Histsize Modify history Storage Bar Number

Histfile Specifies the location of the history file, the default is ~/.bash_history

Histfilesize the number of storage bars for the command that specifies the history file

histtimeformat= "%F%T" shows the specific execution time of each command

Histignore= "STR1:STR2" blocks certain command-sensitive strings from being displayed

control the command history mode :

Environment variables: Histcontrol

Ignoredups Default, ignore duplicate commands, continuous and same as "repeat"

Ignorespace ignores all commands that start with a blank

Ignoreboth equivalent to Ignoredups, Ignorespace 's combination

Erasedups Delete duplicate commands

!n: executes the History command historical output corresponding to the ordinal n command

!n: executes the last nth command in history

Some of the basic features of bash on Linux: