3 Shell & command line

10 entries match these filters

• 0049 Pipes and redirection: connecting commands A pipe sends one command's output into another command, and redirection sends output to a file. Together they let small tools build… Beginner · Concept · Linux, macOS Article Basics · Text processing 15 Oct 2026
• 0050 File permissions: chmod, chown and what 755 means Every file has an owner, a group and read/write/execute permissions for three kinds of users. chmod changes the permissions and chown changes… Beginner · Concept · Linux, macOS Article Basics 15 Oct 2026
• 0051 Environment variables and PATH Environment variables are named settings that every program inherits from the shell. PATH is the one that tells the shell where to… Beginner · Concept · Linux, macOS Article Basics 15 Oct 2026
• 0052 Slice and summarize text with grep, sort, uniq, cut, awk and sed A handful of classic tools can filter, count, extract and rewrite text right in the terminal. This guide shows the patterns you… Intermediate · How-to · Linux, macOS Article Finding files & text · Text processing 15 Oct 2026
• 0053 Set up SSH keys: ssh-keygen, ssh-copy-id and ~/.ssh/config SSH keys let you log in to servers and push to Git hosts without typing a password. Create an ed25519 key, install… Beginner · How-to · Linux, macOS, Windows Article Keys & config 15 Oct 2026
• 0054 Fix: Permission denied (publickey) The server refused every key your SSH client offered. Find out which key was offered, make sure its public half is on… Intermediate · Fix · Linux, macOS, Windows Article Keys & config 15 Oct 2026
• 0057 Shell cheat sheet: everyday commands A quick reference for moving around, managing files, viewing and searching text, checking processes and disk space in bash and zsh, with… Beginner · Reference · Linux, macOS Article Basics · Command-line tools 15 Oct 2026
• 0186 Fix: Ansible UNREACHABLE! Failed to connect to the host via ssh Ansible could not open an SSH session to the host, so no task ran. The text after the colon tells you why:… Intermediate · Fix · Linux, macOS Article Ansible · SSH & servers 15 Oct 2026
• 0254 Automate three servers with Ansible: roles, templates, Vault and safe dry runs Build a real Ansible project for two web servers and one database server: inventory groups, SSH keys, roles, templates, handlers, an encrypted… Intermediate · Tutorial · Linux, macOS Article Ansible · Keys & config 15 Oct 2026
• 0265 Turn a one-liner into a robust bash script: strict mode, options, logging, traps, locking and a schedule Grow a find-and-gzip one-liner step by step into a dependable bash script with strict mode, getopts, usage text, logging, error traps, dry-run,… Intermediate · Tutorial · Linux, macOS Article Services & systemd · Shell scripting 15 Oct 2026