3 Shell & command line

Every entry filed under Shell & command line and its subtopics.

13 entries

0424 Cron-safe wrapper: lock, log and report failures for any scheduled command Wrap any cron or timer job so it never runs twice at once, writes a timestamped log, keeps the exit code and… Intermediate · Step by step · Linux Script cron & timers · Shell scripting 15 Oct 2026
0425 jq cheat script: pretty-print, filter and flatten JSON from a file or stdin A small read-only bash wrapper around jq with the recipes you keep looking up: pretty, compact, sorted keys, list paths, pick fields,… Beginner · Cheat sheet · Linux, macOS Script jq & JSON on the command line · Modern command-line tools · Text processing 15 Oct 2026
0366 restic backup wrapper with tagging, retention and a weekly check A bash wrapper that runs restic backup on a fixed list of paths, applies a keep-daily/weekly/monthly policy with forget and prune, runs… Intermediate · Step by step · Linux, macOS Script Backup tools · Backups & syncing 15 Oct 2026
0367 verify-latest-backup: alert when the newest dump is too old or too small A read-only bash check that finds the newest file in a backup directory, compares its age and size against limits, optionally tests… Beginner · Step by step · Linux Script Backups & syncing · Strategy & restore drills 15 Oct 2026
0335 Docker cleanup script with dry run and confirmation A bash wrapper around docker system prune that shows disk usage and lists what would be removed, supports a dry-run flag, and… Beginner · Step by step · Linux, macOS Script Docker basics · Shell scripting 15 Oct 2026
0178 Create a sudo user with an SSH key and disable password login A bash script that creates an admin user in the sudo or wheel group, installs their SSH public key and can switch… Advanced · Step by step · Linux Script Keys & config · Users, sudo & hardening 15 Oct 2026
0109 A vzdump wrapper script with checks, retention and a log file A Bash wrapper around vzdump that checks the target storage first, backs up chosen guests or all guests with zstd and keep-last… Intermediate · Step by step · Linux Script Backup & restore · Shell scripting 15 Oct 2026
0108 List all Proxmox VE guests with status and locks (pvesh + jq) A Bash script that lists every VM and container in the cluster with node, status, lock, memory and uptime, using the Proxmox… Intermediate · Cheat sheet · Linux Script Shell scripting · VMs & containers 15 Oct 2026
0076 jq recipes: 23 one-liners for JSON on the command line A runnable collection of jq filters for everyday JSON work: pick fields, filter with select, reshape, sort, count, group, pass shell variables,… Intermediate · Cheat sheet · Linux, macOS, Windows Script Command-line tools · jq & JSON on the command line 15 Oct 2026
0058 Safe bash script template with set ‑euo pipefail and trap A starting point for bash scripts that stops on errors, rejects unset variables, cleans up temp files on exit and parses options.… Intermediate · Cheat sheet · Linux, macOS Script Shell scripting 15 Oct 2026
0059 Incremental snapshot backups with rsync A bash script that copies a folder into dated snapshots with rsync, hard-links unchanged files to the previous snapshot to save space,… Advanced · Step by step · Linux, macOS Script Backups & syncing · Shell scripting 15 Oct 2026
0060 Find the biggest files and folders eating your disk A short bash script that lists the largest files over a size limit and the largest subfolders, using find, du, sort and… Beginner · Step by step · Linux, macOS Script Finding files & text · Text processing 15 Oct 2026
0061 Fix: Address already in use (free a busy port) Your server cannot start because another process already listens on its port. This script shows which process holds the port and stops… Intermediate · Fixes an error · Linux, macOS Script Processes & ports · Shell scripting 15 Oct 2026