Practical steps to remove command history from your shell while understanding the limits of secure deletion. 16.11.2025 | reading time: 2 min Command-line history can leak passwords and secrets; this guide shows concrete steps to remove Bash history from memory and disk and explains when deletion is or is not truly secure. Hands-on example Imagine a technician who finished a session on a shared machine and wants no trace left: first prevent the session from writing to disk with `unset HISTFILE`, then clear the in-memory list with `history -c`, then overwrite the history file with `history -w` and finally securely remove the file with `shred -u -z ~/.bash_history`, verifying with `ls -la ~/.bash_history` to confirm absence. Why those steps work Do them in order: `unset HISTFILE` stops the shell from saving at exit, `history -c` clears the current session history, `history -w` writes the empty list to the HISTFILE so it no longer contains commands, and `shred` overwrites and deletes the file; still, overwriting can fail on SSDs, copy-on-write or journaling filesystems, so understand the limits. Shells, logs and pitfalls Different shells keep different files like `~/.zsh_history` or `~/.config/fish/fish_history` and system services may record activity elsewhere, so removing a history file does not erase syslog, auditd, bash logs in /var, or backups; be aware of multiplexers and remote session logs as well. Other practical options Consider alternatives: use full-disk encryption to protect historical artifacts, set `HISTSIZE` and `HISTFILESIZE` to zero for ephemeral sessions, and combine secure-deletion tools with operational controls such as restricted sudo logs and centralized auditing to reduce data leakage. Closing path forward Securely clearing shell history is straightforward but imperfect; learn the tools, know filesystem limits, and build habits that avoid placing secrets on the command line, and if you want to deepen your LINUX skills consider exam paths like CompTIA Linux+ or LPIC-1 and intensive preparation at bitsandbytes.academy. Join Bits & Bytes Academy First class LINUX exam preparation. security utilities scripting
