history

history linux command cheatsheet by Thamizhiniyan C S

Introduction

This command is used to display the history list with line numbers.

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Syntax

history [-c] [-d offset] [n] or history -anrw [filename] or history -ps arg [arg...]

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Important Flags

Flag	Description
-c	Clear the history list by deleting all of the entries.
-d offset	Delete the history entry at position OFFSET. Negative offsets count back from the end of the history list.
-a	Append history lines from this session to the history file.
-n	Read all history lines not already read from the history file and append them to the history list.
-r	Read the history file and append the contents to the history list.
-w	Write the current history to the history file.
-p	Perform history expansion on each ARG and display the result without storing it in the history list.
-s	Append the ARGs to the history list as a single entry.

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Executing Command without making an entry in history

Executing a command with space character " " as a prefix will get the job done.

# The following command won't make an entry in history since it is prefixed 
# with a space character
  echo "Some Kinda API Key"

Disabling and Enabling history

To prevent recording commands in the history list, temporarily disable recording by using:

set +o history

To re-enable recording, use:

set -o history

The commands have no output

Interactive Mode Commands

Flag	Description
ctrl-P	Move to the previous history entry. This is the same action as the up arrow.
ctrl-N	Move to the next history entry. This is the same action as the down arrow.
alt-<	Move to the beginning (top) of the history list.
alt->	Move to the end (bottom) of the history list, i.e., the current command line.
ctrl-R	Reverse incremental search. This searches incrementally from the current command line up the history list.
alt-P	Reverse search, non-incremental. With this key, type in the search string and press enter before the search is performed.
alt-N	Forward search, non-incremental.
ctrl-O	Execute the current item in the history list and advance to the next one. This is handy if you are trying to re-execute a sequence of commands in the history list.

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Additional Features of history

Flag	Description
!!	Repeat the last command. It is probably easier to press the up arrow and enter.
![number]	Repeat history list item number.
![number]:p	Displays the command associated with event number without executing it.
!-[number]	Add a dash (-) before the command number to run a specific command from the end of the list.
![string]	Repeat last history list item starting with string.
!?[string]	Repeat last history list item containing string.
^[old string]^[new string]^	If you made a typo in a previous command, change it using this syntax. You can find a detailed example below

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Examples

Command	Description
history	Displays the command history.
history 5	Shows the last 5 commands from the command history.
!1997	Reruns the command with event number 1997.
!1997:p	Displays the command associated with event number 1997 without executing it.
!-7	To reuse the seventh last command
history | grep chpasswd	Filters and displays only the commands containing the term “chpasswd.”
!!	Reruns the last executed command.
!command_starting_string	Executes the latest command starting with “command_starting_string.”
history -d 1996	Removes the command with event number 1996 from history.
history -c	Clears the entire command history.
history | tail	Displays the last 10 commands from the history.

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Customizing history output to show datetime stamps

Add the following line to the .bashrc file:

export HISTTIMEFORMAT="<DateTime_Format>"

Available Date Time Formats	Description
%d	Day.
%m	Month.
%y	Year.
%H	Hour.
%M	Minutes.
%S	Seconds.
%F	Full date (Y-M-D format).
%T	Time (H:M:S format).
%c	Complete date and timestamp (Day-D-M-Y H:M:S format).

For example, To view the complete date and timestamp for each command in history, use the following format:

export HISTTIMEFORMAT="%c "

Now save the file and run the command source .bashrc or open a new terminal and run the history command to see the DateTime stamps.

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Fixing Typos in Previous Command

If you made a typo in a previous command, use the following syntax to fix it:

^[old_string]^[new_string]^

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References

Linux history Command with ExamplesKnowledge Base by phoenixNAP

How to Display Command History in Linux | history Command - GeeksforGeeksGeeksforGeeks