History command and search in Linux CLI - Commands & Configuration

Introduction

Sometimes you forget the exact command you typed before or want to repeat a previous command quickly. The history command helps you see past commands, and searching lets you find the one you need without scrolling through everything.

When you want to repeat a command you ran earlier without retyping it all.

When you need to find a command you used days ago but don’t remember exactly how it looked.

When you want to check what commands you or someone else ran on the system.

When you want to save time by reusing complex commands from your history.

When you want to search for commands related to a specific task or keyword.

Commands

This command shows a numbered list of all the commands you have typed in the current shell session and previous ones saved in the history file.

Terminal

history

Expected Output

  1  ls -l

  2  cd /var/log

  3  cat syslog

  4  history

This command searches your command history for any commands containing the word 'git'. It helps you find specific commands quickly.

Terminal

history | grep git

Expected Output

  15  git status

  23  git commit -m 'fix bug'

  42  git push origin main

Pressing Ctrl + r starts a reverse search in your command history. You can type part of a command, and it will show the most recent match. Press Enter to run it or Ctrl + r again to find earlier matches.

Terminal

Ctrl + r

Expected Output

(reverse-i-search)`git': git push origin main

This runs the command numbered 42 from your history list. It saves time by letting you rerun a command without typing it again.

Terminal

!42

Expected Output

Everything pushed to origin main branch

Key Concept

If you remember nothing else from this pattern, remember: the history command and reverse search let you quickly find and reuse past commands without retyping.

Common Mistakes

Trying to run ! without a number or valid command reference

The shell will give an error because it doesn't know which command to run.

Use ! followed by a valid history number or command prefix, like !42 or !git.

Not pressing Ctrl + r to start reverse search and instead scrolling manually

Manually scrolling through history is slow and inefficient.

Use Ctrl + r and type part of the command to quickly find it.

Using history without piping to grep when searching for a specific command

You get a long list and have to look through everything manually.

Use history | grep keyword to filter commands by keyword.

Summary

Use the history command to list all past commands with numbers.

Use history | grep keyword to search commands containing a specific word.

Use Ctrl + r to interactively search and reuse previous commands quickly.

Use !number to rerun a command from the history list by its number.