TODO LINUX Explicado En 11 Minutos (Ahora Lo Entenderás Todo) — Transcript

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1. 0:00Installing Linux begins with a rather
2. 0:02peculiar decision. Choosing which one:
3. 0:06Ubuntu, Debian, Mint, Arch. And you
4. 0:10wanted an operating system because
5. 0:11you’re fed up with Windows or because
6. 0:13you’re the type to go against
7. 0:15what’s popular. That doesn't matter
8. 0:17right now. The thing is, you’ve ended
9. 0:19up looking at an endless catalog. Let's
10. 0:22get straight to the point. Linux is not
11. 0:23an operating system. It’s the kernel,
12. 0:27the core that manages memory. It
13. 0:29allocates processor time to programs
14. 0:32and lets software use the hardware. It
15. 0:34works underneath everything else.
16. 0:36It’s not the menu where you open the
17. 0:38browser. What you usually install is a
18. 0:40distribution—that core accompanied by
19. 0:43tools, apps, and a system to install
20. 0:45and update programs. Many of those
21. 0:47tools come from the GNU project, hence
22. 0:50the name GNU/Linux. In conversation,
23. 0:53saying "I use Linux" is perfectly
24. 0:55understood. It makes you a user with
25. 0:57more love for computing than a Windows
26. 1:00user, but don't go showing off. Don't
27. 1:02get mad, I'm just joking. I’ll go
28. 1:05back to being serious now. There’s
29. 1:07another piece: the desktop environment.
30. 1:10It’s what gives you windows, panels,
31. 1:12and menus. The same distribution can
32. 1:15offer several. Linux Mint, for example,
33. 1:18has editions with Cinnamon or Mate,
34. 1:20among others. That’s why two
35. 1:22computers with Linux can look very
36. 1:25different. Changing the desktop doesn't
37. 1:28mean changing the distribution. And yes
38. 1:30, you can open folders, install apps,
39. 1:33and use the browser with a mouse. The
40. 1:36terminal is useful, but you don't need
41. 1:38to cast a spell to open a photo. The
42. 1:43terminal is intimidating until you
43. 1:45discover you can change the background,
44. 1:46turn the text green, and still not know
45. 1:48what you're doing, but with impeccable
46. 1:50style. Let’s separate two things that
47. 1:54are often confused. The terminal is the
48. 1:56application where you type commands and
49. 1:58see the results. The shell is the
50. 2:01program that interprets what you type
51. 2:03and executes the orders. Bash and ZSH
52. 2:06are two examples. You can change the
53. 2:08terminal and keep using the same shell.
54. 2:11The window changes, but the thing
55. 2:12interpreting your instructions stays
56. 2:14the same. A command can be as simple as
57. 2:17"ls," which lists the content of a
58. 2:19folder. You can add options to modify
59. 2:22its behavior. "ls-l" shows a list with
60. 2:26details like permissions and file size.
61. 2:31Some commands are standalone programs,
62. 2:33others come built into the shell like "
63. 2:35cd," which changes your current
64. 2:37directory. And you don't need to
65. 2:39memorize them all. "help" in Bash
66. 2:42explains the built-in commands. For
67. 2:44many others, "man" opens their manual.
68. 2:46The tab key also helps to autocomplete
69. 2:49command and file names. The advantage
70. 2:51appears when you have to repeat a task.
71. 2:54Writing a command can save you a bunch
72. 2:56of clicks, especially when the
73. 2:58alternative is renaming 500 files and
74. 3:00starting to question your life choices.
75. 3:04In Linux, files are organized in a tree
76. 3:07that starts with a slash, the root.
77. 3:09From it, all other folders branch out,
78. 3:11also called directories. Usually, your
79. 3:14documents are inside home, in your user
80. 3:17folder, and so on. It holds system
81. 3:20configuration, and var contains
82. 3:22changing data, like many activity logs.
83. 3:25There is an order. Even if the names
84. 3:27look like they were chosen during a
85. 3:29keyboard malfunction, disks also fit
86. 3:32into that tree. When you plug in a
87. 3:34flash drive, its file system is mounted
88. 3:36to a directory. You access its content
89. 3:39by entering that folder. On many
90. 3:41desktops, this happens automatically.
91. 3:44Mounting doesn't mean copying files to
92. 3:46the computer; it means making them
93. 3:48accessible from a point in the tree.
94. 3:50You can also find links. A symbolic
95. 3:54link points to the path of another file
96. 3:56or folder, much like a shortcut. If the
97. 4:00destination disappears, the link
98. 4:01becomes broken. A hard link works
99. 4:04differently. It is another name for the
100. 4:07same file. It does not create a copy.
101. 4:09Both names allow access to the same
102. 4:11content. Deleting one doesn't remove
103. 4:14the file as long as the other still
104. 4:15exists. And to investigate where your
105. 4:18space has gone, you have two commands.
106. 4:21DF shows the used and available space
107. 4:24on file systems. Du calculates how much
108. 4:27space files and folders occupy. Very
109. 4:30useful when your downloads folder
110. 4:32already has archaeological value like
111. 4:34mine. Just because a file is on your
112. 4:38computer doesn't mean your user can
113. 4:40modify it. Linux uses permissions to
114. 4:43decide who can do what. Each file has
115. 4:46an owner and a group. Basic permissions
116. 4:50distinguish between that owner, members
117. 4:52of the group, and other users. Read,
118. 4:55write, and execute. On a file, they
119. 4:59allow reading its content, modifying it
120. 5:01, or executing it as a program. In a
121. 5:04folder, their meaning changes. For
122. 5:06example, execute allows you to go
123. 5:08through it to access what it contains.
124. 5:10You can adjust those permissions with
125. 5:12chmod. Giving everyone access to get
126. 5:16rid of an error is roughly like ripping
127. 5:18off the door because you lost the keys.
128. 5:21To manage the system, there is Root,
129. 5:23the superuser, with very broad
130. 5:25permissions. Don't confuse it with the
131. 5:28root of the file tree. They share the
132. 5:30name, but one is an account and the
133. 5:32other is a directory. With sudo, an
134. 5:36authorized user can run a command as
135. 5:38another user, usually root, without
136. 5:41starting a full admin session. That
137. 5:44doesn't fix the command; it gives it
138. 5:46more authority. If you make a mistake,
139. 5:49you make it with permissions. A common
140. 5:53way to install programs is to use a
141. 5:55package manager. You ask for an
142. 5:58application, and it handles downloading
143. 6:00, installing, and managing the parts it
144. 6:02needs to run. Those parts are the
145. 6:05dependencies, libraries, or other
146. 6:07programs that the application uses.
147. 6:10This way, you don't have to look for
148. 6:12them one by one as if you were filling
149. 6:14an error album. Software is usually
150. 6:16downloaded from repositories, servers
151. 6:18with packages prepared for your
152. 6:20distribution. The manager also allows
153. 6:22you to update those packages and remove
154. 6:25them. Debian and Ubuntu use APT, Fedora
155. 6:28uses DNF, and Arch uses Pacman. Here,
156. 6:32Pacman installs programs. We'll leave
157. 6:34eating up the disk to the web browser.
158. 6:36There are also different package
159. 6:38formats like DEB and RPM files. Just
160. 6:41because a program is available for
161. 6:43Linux doesn't mean any package works
162. 6:45for any distribution. To facilitate
163. 6:47that compatibility, there are Flatpak,
164. 6:50Snap, and AppImage. They solve in
165. 6:52different ways how to distribute
166. 6:54applications and their dependencies for
167. 6:56various systems. AppImage, for example,
168. 6:59usually lets you download a file and
169. 7:01run it without a traditional
170. 7:03installation, but they don't guarantee
171. 7:05everything will work on any computer.
172. 7:08Compatibility requirements and limits
173. 7:10still exist, and many distributions
174. 7:12have a graphical store that uses these
175. 7:14systems underneath. You click install,
176. 7:18and the manager does the work. An
177. 7:20installed program is waiting on the
178. 7:22disk. When it runs, a process
179. 7:25identified by a number called a PID
180. 7:27comes into play. An application can use
181. 7:30several processes at once to see which
182. 7:32are active and how much processor or
183. 7:35memory they consume. You have tools
184. 7:38like top or htop. This way, you can
185. 7:40locate the culprit when the fan starts
186. 7:42preparing for takeoff. You can also
187. 7:45send signals to the processes. SIGTERM
188. 7:47requests they terminate and allows them
189. 7:49to manage their shutdown. SIGKILL
190. 7:51forces their termination without giving
191. 7:54them that opportunity. Other programs
192. 7:56work in the background without a window
193. 7:58that you have to keep open. They are
194. 8:01known as daemons and can handle remote
195. 8:03connections or execute scheduled tasks.
196. 8:06The name sounds much worse than the job
197. 8:08. Many distributions use systemd to
198. 8:11organize startup and manage services.
199. 8:14It can start them, stop them, or
200. 8:16configure them to activate upon booting
201. 8:19. Starting a service now and enabling
202. 8:21it for future startups are different
203. 8:24things. And there is swap, a swap space
204. 8:27that can store part of the memory
205. 8:29content to free up RAM. When it uses
206. 8:32the disk, accessing that data is much
207. 8:34slower. It helps manage memory, but it
208. 8:37doesn't turn an 8 GB computer into a 16
209. 8:40GB one with a free trick. To automate a
210. 8:45task, you can write a shell script, a
211. 8:47text file with instructions, for
212. 8:49example, to copy a folder, compress it,
213. 8:52and save a backup with the date. You
214. 8:56can also connect commands using pipes,
215. 8:58the famous pipes. The output of one
216. 9:02becomes the input of the next. One
217. 9:04reads a log, another filters lines with
218. 9:07errors, and another counts them. Each
219. 9:10tool does a part of the job. This makes
220. 9:13use of three standard channels:
221. 9:15standard input, standard output, and
222. 9:18standard error. You can redirect them
223. 9:21to read data from a file or save
224. 9:23results and errors separately. The
225. 9:26shell also uses variables. One
226. 9:29especially useful one is PATH, which
227. 9:31indicates which directories to search
228. 9:33for programs when you type their name
229. 9:35without the full path. And to execute
230. 9:37tasks at certain times, there is Cron.
231. 9:41You can schedule a backup every night,
232. 9:43as long as the computer is on and Cron
233. 9:45is running. Automate. It avoids
234. 9:50repeating work, but it also repeats
235. 9:52your mistakes with admirable
236. 9:53punctuality. First, verify that the
237. 9:56script does what you want. Then, give
238. 9:58it permission to do it while you sleep.
239. 10:03With SSH, you can connect to another
240. 10:05computer and execute commands via an
241. 10:07encrypted connection. Very useful for
242. 10:10managing a server without having it in
243. 10:12front of you. To control what network
244. 10:14traffic you allow, you use a firewall.
245. 10:17Tools like UFW make it easy to
246. 10:19configure its rules, and when something
247. 10:22fails, check the logs. In systems with
248. 10:26Systemd, journalctl allows you to
249. 10:28review the services and system logs.
250. 10:31Sometimes the error is explained there
251. 10:33while you’ve spent 20 minutes blaming
252. 10:35the router. You can also run
253. 10:37applications in containers with Docker.
254. 10:40Linux containers isolate processes and
255. 10:42share the kernel of the system where
256. 10:45they run. A virtual machine, on the
257. 10:48other hand, runs an operating system
258. 10:50with its own kernel on virtual hardware
259. 10:52. That allows you to test another
260. 10:54system without replacing the one you
261. 10:56have installed. But I will explain this
262. 10:58Docker topic more thoroughly in another
263. 11:01video. Don't get overwhelmed by that. I
264. 11:03think you already know the basics of
265. 11:05Linux. And as a user, if you like
266. 11:07computing and like to be God before a
267. 11:09computer and not a sheep, I recommend
268. 11:12you try it for a month. If you don't
269. 11:15like it, you can always switch at any
270. 11:17time. To start, I recommend Linux Mint.
271. 11:20It's the one I started with, and it's
272. 11:22not very complicated. That's it for
273. 11:24today's video, my technocrockers. I
274. 11:26hope you enjoyed watching the video as
275. 11:28much as I enjoyed making it. Leave me
276. 11:30your questions in the comments, bro.
277. 11:32See you in the next video. Regards. M.