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The Art of Technical Troubleshooting

Category: Tech Trivia

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Create BACKUP of Linux Files Before Editing

Before editing any important file, the best practice is to create a backup of it. The extensions “.bak”, “.sav”, “.old”, and “.orig” are all popular ways of indicating a backup file. So, create the simplest backup using .bak: Now, if we run ls, we can see that .bashrc.bak appears slightly dimmed: If you need to,
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Classes of IPv4 Address

There are around 4.3 billion IPv4 addresses and managing all those addresses without any classification is next to impossible. For easier management and assignment IP addresses are organized in numeric order and divided into the following 5 classes: IP Class Address Range Maximum number of networks Class A 1-126 126 (27-2) Class B 128-191 16384
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Do you know how to kill?

Most people use the kill command in its simplest form: and assume that this is all the command can do. Many users are unaware that kill supports numerous additional options and signal types. In fact, kill does not simply “kill” a process — it sends a signal. By default, it sends SIGTERM (15), but it
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Big Three Prefix

What connects the “Big Three”: The prefix “ch” stands for “change.”
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The “Superuser” Evolution

Most people think sudo stands for “superuser do,” but it originally meant “substitute user do.” In modern Linux like Ubuntu, the root account is disabled by default (no password), making the classic su - command unusable. Instead, Ubuntu users rely on sudo -i to simulate a login shell. This “sudo-only” approach is safer because it
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