Jayant Verma

Moving between folders in a terminal starts with knowing which directory the shell is working in. The cd command changes the shell’s current directory to a path or a destination such as your home directory. This article explains how to choose a path to a directory and use cd’s shortcuts to move from there. TL;DR

An unfamiliar directory can contain several layers of folders, making its contents harder to scan. The tree command displays those folders and their files in a branching hierarchy. This article covers installing tree and tailoring its output with depth limits and name filters. TL;DR The tree command prints a directory and its contents as an

Fetching a URL from a Linux shell can leave you deciding whether the response should go into a file or appear in the terminal. Wget and curl are command-line tools for transferring data to and from URLs, and they handle output differently by default. This article compares which command fits common transfer tasks and shows

Checking the accounts on an Ubuntu machine means choosing whether to look at local records or accounts the system can resolve. The getent passwd command looks up records through the machine’s configured account sources, while the /etc/passwd file stores local records. I’ll show you how to list local names and system-resolved accounts, then use a

Copying a file into place can also mean choosing its destination permissions or creating directories along the path. The GNU install utility prepares files and directories from the command line, including copying a file and creating missing parent directories. I’ll show how to set permissions on a copied file and create the directories it needs.

You have text to replace and want the match to work regardless of capitalization. sed searches input text and can replace matches, and its i substitution flag makes the search ignore capitalization. I’ll show how to choose the substitution flags and check the output before an in-place edit. TL;DR: Ignore Case with sed For a

A small change to a file is only useful if you can save it, and you may also need to leave the original unchanged. Vim is a text editor whose keys do different jobs depending on whether you are entering text or issuing commands. I’ll show you how to make and save or discard a

Ask who created Linux and you’ll usually hear one name, Linus Torvalds. He started the Linux kernel in 1991 as a personal project while studying in Helsinki, and a much wider set of developers later built complete systems around it. I’ll trace what came before Linux, from Unix to MINIX, and how the first distributions

The `QUERY TIME` line reports how long the DNS exchange took, not how long a page takes to load. I’m curious that an empty answer can still arrive with `NOERROR`. You can match the response to the name and record type you asked about. Read the reply’s status before interpreting its answer. What a dig