Managing Linux Command History: View, Search, Modify, and Clear

When developing on Linux, re‑typing long commands can be tedious; the up‑arrow only shows recent entries, making it hard to retrieve older commands, especially after closing an Xshell session.

The history command lists the last 1000 commands by default, and you can increase this limit by editing HISTSIZE and HISTFILESIZE in .bash_profile :

<code>echo "HISTSIZE=2000" >> .bash_profile

echo "HISTFILESIZE=2000" >> .bash_profile
source ~/.bash_profile</code>

To display timestamps alongside each entry, set the format variable:

<code>export HISTTIMEFORMAT="%F %T"</code>

Now history shows when each command was executed.

Search the history interactively with Ctrl +r . For example, typing usr after pressing Ctrl +r will locate the command usr/local/nginx/sbin/nginx -t used to test an Nginx configuration.

Repeat the most recent command using the up‑arrow, !! , or !-1 . To execute a specific entry by its number, use !1020 (replace 1020 with the desired index shown by history ).

The history size can be adjusted as shown earlier; the variables control how many entries are displayed ( HISTSIZE ) and how many are stored in the history file ( HISTFILESIZE ). Example entries after modification:

<code> 1039 2021-03-02 22:29:37 echo "HISTSIZE=2000" >> .bash_profile
 1040 2021-03-02 22:29:58 echo "HISTFILESIZE=2000" >> .bash_profile
 1041 2021-03-02 22:30:20 source ~/.bash_profile</code>

To clear the entire history, run:

<code>history -c</code>

Summary

View history with history

Search with Ctrl +r

Repeat last command using !! or !-1

Execute a specific entry with !<em>n</em> (e.g., !1020 )

Adjust displayed count via HISTSIZE

Adjust stored count via HISTFILESIZE

Clear history with history -c