How to Use History Command in Linux

The history Linux command is a handy tool that displays a list of all the commands that a user has previously executed in the terminal. This list is stored in a history file, and by using the history command, you can view this file, making it easier to recall and reuse past commands.

This command is commonly used to track actions performed in the terminal, especially when troubleshooting or repeating complex command sequences. It can save time and effort by allowing users to quickly recall and rerun previous commands without having to type them out again. Some users also utilize the history to audit or review actions taken in the system, aiding in system administration and security.

General syntax for history command:

history [OPTIONS...]

1. Show used commands

history [number]

This command displays a limited number of previously executed commands.

Example:

The history 5 command in Linux will display the last 5 commands that were executed in the terminal. Here’s a sample output:

  501  git status
  502  cd /var/www/html
  503  ls -la
  504  nano myfile.txt
  505  history 5

Each line shows a command from the history, preceded by a unique number that represents the command’s position in the history file. In this example, the last five commands that were run are shown, including the history 5 command itself.

2. Delete commands from history list

history -d [number]

Use the -d option to delete commands from the history list.

Example:

Before deleting:

1  ls
2  cd Documents/
3  touch file.txt
4  nano file.txt
5  rm file.txt
6  history

After running history -d 5:

1  ls
2  cd Documents/
3  touch file.txt
4  nano file.txt
5  history

As you can see, the 5th command (rm file.txt) has been removed from the history.

3. Search used command within history

history | grep [text]

The history | grep command helps you find commands that match a text pattern.

Example:

The history | grep cat command in Linux will search through your command history and display all the lines that contain the word “cat.” The grep command filters the output of the history command to only show lines with the specified pattern, in this case, “cat.” Here’s a sample output:

  42  cat file.txt
  73  cat /etc/passwd
 100  cat documents/note.txt | more
 123  concatenate file1.txt file2.txt > combined.txt
 150  cat logs/error.log | grep "ERROR"

In this example, each line begins with a number representing the command’s position in the history, followed by the command itself. It includes every instance where “cat” appears, whether it’s the cat command itself or just part of another word or command.

4. Clearing the history list

history -c

The -c (clear) option is used to clear all commands from the history list.

5. Execute the command with event number

!number

This command allows you to execute commands with an event number from the history list. There is no need to write a complete command.

Example:

Suppose the 10th command in your history was ls -l, which lists files in the current directory in long format. If you run !10, the output might look something like this:

total 24
drwxr-xr-x 5 user user 4096 Aug  6 10:00 Documents
drwxr-xr-x 2 user user 4096 Aug  6 09:45 Downloads
drwxr-xr-x 2 user user 4096 Aug  6 09:45 Music
drwxr-xr-x 2 user user 4096 Aug  6 09:45 Pictures

This output shows the contents of the current directory, just as if you had run the ls -l command directly.

6. Write changes to bash_history file

history -w [filename]

Use this option to write all changes made in the current session to the bash_history file.

Example:

The history -w file.txt command in Linux doesn’t produce output in the terminal itself. Instead, it writes the current history of commands to a file named file.txt.

So, if you were to open file.txt, you might see something like this:

1 cd /home/user/documents
2 ls -la
3 sudo apt-get update
4 nano file.txt
5 history -w file.txt

This file now contains the list of commands that were previously executed in the terminal, and you can view or edit it using any text editor.

More Linux commands: