Learn how bash runs commands, automates tasks and becomes the operator's best tool. 22.02.2026 | reading time: 2 min Bash is the default interactive shell on many Linux systems and the scripting language that ties system tasks together; here you will see how to use it to run commands and automate routine work. Automate a Log Cleanup Example: create a small bash script to move logs older than seven days to an archive and run it; the script and a sample run are shown below. ```#!/usr/bin/env bash set -euo pipefail shopt -s nullglob mkdir -p /var/log/myapp/archive for f in /var/log/myapp/*.log; do if [[ $(stat -c %Y "$f") -lt $(date -d '7 days ago' +%s) ]]; then mv "$f" /var/log/myapp/archive/ echo "Archived: $f" fi done ``` Run it with `bash cleanup_logs.sh` and you might see: ```$ bash cleanup_logs.sh Archived: /var/log/myapp/error.log Archived: /var/log/myapp/access.log ``` What Bash Really Offers Bash is more than a prompt: it provides powerful parameter expansion, arrays, process substitution, job control, here-docs and programmable completion; use `bash -c` to run a command from another process, `-i` for interactive shells and `--login` for login behaviour, and prefer POSIX constructs when portability matters. When to Reach for Other Tools For pure POSIX scripts use /bin/sh to maximize portability because some systems link it to dash; for interactive experience consider zsh, and combine bash with tools like awk, sed and GNU coreutils to process text and data efficiently. Next Steps Practice by converting manual workflows into small bash scripts, test edge cases and version your scripts in a repository; deepen knowledge for exams like CompTIA Linux+ or LPIC-1 and consider intensive preparation at bitsandbytes.academy to make your skills certification-ready. Join Bits & Bytes Academy First class LINUX exam preparation. scripting utilities processes
