Tag: linux

The Linux commands every sysadmin reaches for daily, file ops, process management, networking, and text manipulation you can't live without.

Apt says packages have been kept back during upgrade. What the message means on Debian 12 and Ubuntu, why it happens, and how to install those packages safely.

Upgrade one package with apt and leave the rest alone. The exact flag, why apt upgrade nginx does not work, version pinning, and held package behaviour.

Move Docker images between hosts without a registry using docker save and docker load, air-gapped deployments made simple.

Use docker cp to move files between running containers and your host machine, no volumes needed for one-off file transfers.

Access services on the host machine from inside a Docker container using host-gateway or host.docker.internal, no hardcoded IPs.

Containers share the kernel; VMs have their own. Understand the isolation trade-offs, overhead differences, and when to use which.

regreSSHion (CVE-2024-6387) is a remote code execution bug in OpenSSH, what it is, which versions are affected, and how to patch fast.

Run multiple commands in one docker exec call by piping a heredoc to the container shell, chain dependent steps and skip repeated container roundtrips.

xargs turns stdin into arguments, build complex pipelines, run parallel jobs, and handle filenames with spaces without breaking everything.

Advanced FFmpeg techniques, filter graphs, stream mapping, subtitle burning, speed adjustment, and batch processing scripts.

Shell globbing breaks inside docker exec because of how args are parsed, here's how to pass wildcards and asterisks correctly.