1 00:00:00,930 --> 00:00:08,850 Changing gears shall prompt your share from the environment variable here provides you with useful information, 2 00:00:08,850 --> 00:00:14,850 such as the user you are operating as and the director in which you're currently working. 3 00:00:15,120 --> 00:00:18,930 So the default should prompt in color text the following year. 4 00:00:19,380 --> 00:00:27,480 Users here can use their name, first name and current, uh, current directory. 5 00:00:29,310 --> 00:00:36,450 So if you're working with the real route user, this translates to this, for example, root at Cowley 6 00:00:36,450 --> 00:00:39,300 and Core and Directory. 7 00:00:43,540 --> 00:00:49,750 So you can change the name in the default shopfront by setting the value from the Florida is one variable 8 00:00:49,750 --> 00:00:55,600 that so the is one variable has set of placeholders for information you want to display in the prompt, 9 00:00:56,260 --> 00:01:03,010 including the name of the current user, the host name and the base name of the current working directory. 10 00:01:04,030 --> 00:01:11,050 So this is very useful if you happen to have shows on multiple systems are a little bit on an as multiple 11 00:01:11,050 --> 00:01:11,530 accounts. 12 00:01:11,550 --> 00:01:18,970 So by setting different users and host names and values for different channels or accounts, you can 13 00:01:18,970 --> 00:01:23,410 tell at a glance who you are and what your current system is. 14 00:01:23,890 --> 00:01:27,460 So let's have a little fun on showing the prompt in your terminal. 15 00:01:27,460 --> 00:01:30,780 For example, you could enter here. 16 00:01:30,860 --> 00:01:31,960 Pierce one. 17 00:01:33,170 --> 00:01:43,250 Here, uh, for example, uh, World's best anchor here and his shtick here. 18 00:01:45,180 --> 00:01:49,950 As you can see here now, our common theme is like that here. 19 00:01:50,580 --> 00:01:56,040 So now every time you use this terminal, you will be reminded that you are the world's best hacker. 20 00:01:56,400 --> 00:02:02,670 But any subsequent terminal you open will still have the default command ground because the P is one 21 00:02:02,670 --> 00:02:06,030 variable only those values for your terminal session. 22 00:02:06,360 --> 00:02:10,860 Remember, until you export a variable, it is only good for that session. 23 00:02:11,280 --> 00:02:17,740 So if you really like this new command prompt and want to see it in every terminal, you need to take 24 00:02:18,000 --> 00:02:19,020 a unit to export it. 25 00:02:19,020 --> 00:02:21,840 So like that, export P.S. one. 26 00:02:21,840 --> 00:02:30,690 But I will not do it in this year, so this will make the chains so chain dependent across all sessions. 27 00:02:31,570 --> 00:02:33,360 How about a little more fun? 28 00:02:33,390 --> 00:02:38,670 Here's the thing you really want your terminal to look like the Windows CE in the prompt. 29 00:02:39,420 --> 00:02:43,730 So that's actually it's quite boring actually here. 30 00:02:44,790 --> 00:02:51,000 So say you really want your terminal to look like a windows in the prop. 31 00:02:51,390 --> 00:02:56,760 So in this case, you can't change the prompt name you see and keep it down below. 32 00:02:56,760 --> 00:03:03,060 Have to control your current directory as here, for example, export. 33 00:03:04,130 --> 00:03:11,210 Export p es from excellent experience one. 34 00:03:11,780 --> 00:03:23,600 And here in this film, we see him here, so we see and hear, you know, override Tableau for directory 35 00:03:23,600 --> 00:03:25,430 extrication, as you can see here. 36 00:03:39,010 --> 00:03:39,370 Here. 37 00:03:43,320 --> 00:03:43,710 Like there. 38 00:03:47,620 --> 00:03:50,290 We can do it for some severe bone loss. 39 00:03:51,450 --> 00:03:56,220 Like that, so having a prompt from your current director, it can be generally useful. 40 00:03:56,490 --> 00:03:57,840 So particularly for beginners. 41 00:03:58,170 --> 00:04:05,320 And so it's something to consider when you change your form variable, we can change pet as well. 42 00:04:05,350 --> 00:04:10,410 So one of the most important variables in your environment is pets. 43 00:04:10,440 --> 00:04:12,750 Variable, actually, it's boring, actually. 44 00:04:13,170 --> 00:04:19,860 So let's call it so one of the most important variables in your environment is your pet variable. 45 00:04:20,160 --> 00:04:26,160 So which controls were very on your system your shell will look for come once you enters, such as a 46 00:04:26,160 --> 00:04:28,440 see the list or equal here. 47 00:04:29,160 --> 00:04:41,040 So most commands are located in Espin or bin directory here, like a user locale, spin or user. 48 00:04:41,460 --> 00:04:45,630 Uh, use local being yeah. 49 00:04:46,050 --> 00:04:52,380 If the file doesn't find the command in one of the directors in your pet variable, it will return the 50 00:04:52,380 --> 00:04:54,630 command not formed like that, for example. 51 00:04:56,700 --> 00:04:58,200 Common would and liked it. 52 00:04:59,750 --> 00:05:08,000 So even if that comment does exist in the dire straits and, uh, not in your pet, so you can find 53 00:05:08,000 --> 00:05:16,310 out which directors are stored in your pet variable by using Echo and all our sign and pet. 54 00:05:17,180 --> 00:05:17,480 That's true. 55 00:05:17,550 --> 00:05:19,280 How serious are Patea? 56 00:05:19,850 --> 00:05:24,440 These are the directories where your terminal was searched for any command. 57 00:05:24,950 --> 00:05:33,290 When you enter L.A., for example, the system knows to look in each um, each of these directories 58 00:05:33,290 --> 00:05:33,940 for the L. 59 00:05:33,950 --> 00:05:41,270 S Command and when it finds out as, uh, the system executes it like that was. 60 00:05:43,030 --> 00:05:50,020 So each territory is separated by column, and you don't forget to add the dollar symbol in content 61 00:05:50,020 --> 00:05:51,700 pattern, as you can see here. 62 00:05:52,210 --> 00:05:56,200 So we can add them to the patch variable here. 63 00:05:56,410 --> 00:06:02,840 So you can probably see why it is important to know what is in your patch variable if you downloaded 64 00:06:02,890 --> 00:06:09,310 and install the new tool, let's say, for example, new hacking tool here, uh, into the root new 65 00:06:09,310 --> 00:06:10,510 hacking tool directory. 66 00:06:10,510 --> 00:06:16,960 You could only use commands from that tool and you are in that directory because the directory is not 67 00:06:16,960 --> 00:06:18,100 in the path variable. 68 00:06:18,520 --> 00:06:24,640 Every time you want it to use that, all you called you will first have to navigate routinely new hacking 69 00:06:24,830 --> 00:06:28,840 of which is a bit inconvenient if you want to use tool often. 70 00:06:29,410 --> 00:06:37,240 So to be able to use this new tool for any directory, you need to add the directory, uh, to holding 71 00:06:37,240 --> 00:06:42,370 this tool to your path variable to add new and you hacking tool to your pet's variable. 72 00:06:42,370 --> 00:06:51,160 Enter this command paths here equals here to our path and to that column here. 73 00:06:51,550 --> 00:06:54,880 And, for example, route new hacking tool. 74 00:06:54,880 --> 00:06:57,340 Here we added path variable here. 75 00:06:57,790 --> 00:07:06,100 So this assigns the original patch variable plus this the folder here directory to path to the new path 76 00:07:06,100 --> 00:07:06,520 variable. 77 00:07:06,790 --> 00:07:11,350 So the variable contains everything it did before, plus new tool directory. 78 00:07:12,190 --> 00:07:18,400 If you examine the contents of the patch variable, uh, again you should see that this directory has 79 00:07:18,400 --> 00:07:23,280 been appended to the end of the path, as shown here and Equal Partner X. 80 00:07:25,680 --> 00:07:28,050 Echo what, Pat? 81 00:07:29,370 --> 00:07:34,170 So you can see where that is, uh, a rule, it's new hacking tool here. 82 00:07:34,800 --> 00:07:40,590 So now you can accept new hacking tool applications from anywhere on your system rather than having 83 00:07:40,590 --> 00:07:43,540 navigate to is selected in the Bachelor. 84 00:07:43,570 --> 00:07:46,980 Look in our directories list for your new tool. 85 00:07:48,350 --> 00:07:51,530 So how not to add that valuable? 86 00:07:51,740 --> 00:07:59,030 So one mistake commonly made by new Linux users is assigning a new directory, such as the root new 87 00:07:59,270 --> 00:08:03,620 hiking tool to the patch variable like that had. 88 00:08:04,710 --> 00:08:08,190 Uh, here, uh, route new directory. 89 00:08:11,870 --> 00:08:13,100 New hacking. 90 00:08:14,100 --> 00:08:21,720 Look at this view, if you use this command, you'll pack variable will only contain the new hacking 91 00:08:21,750 --> 00:08:22,140 tool. 92 00:08:22,500 --> 00:08:28,740 So your pet variable will not contain this and you will delete all of these pet variables and only add 93 00:08:28,740 --> 00:08:29,110 this. 94 00:08:30,060 --> 00:08:32,070 This is useless. 95 00:08:32,190 --> 00:08:33,180 Uh, fortunately. 96 00:08:33,750 --> 00:08:35,580 So um. 97 00:08:37,720 --> 00:08:43,330 And no longer contain the system binaries directories such as being on the scene, so after doing this 98 00:08:43,330 --> 00:08:46,980 command, you cannot use LCD or any comments here. 99 00:08:47,760 --> 00:08:54,930 So when you then go to use any of these comments, you will receive the error command not found here. 100 00:08:55,880 --> 00:09:00,810 So remember that you want to append to the pet variable, not replace it. 101 00:09:00,820 --> 00:09:05,940 So if you are in doubt, send the contents of the variable somewhere before you modify it. 102 00:09:07,420 --> 00:09:07,870 So. 103 00:09:09,130 --> 00:09:15,250 We can create a user defined variable as well, so you can create your own custom user defined variables 104 00:09:15,250 --> 00:09:19,600 in Linux by simply assigning evaluate will be a new variable that you name. 105 00:09:20,230 --> 00:09:28,060 So this may be useful when you are doing the same as some more advanced scripting or find you are often 106 00:09:28,240 --> 00:09:32,500 using a long common that you get tired of typing over and over. 107 00:09:32,830 --> 00:09:38,260 So the syntax is straightforward enter the name of your variable, followed by assignment, assignment 108 00:09:38,270 --> 00:09:46,270 symbol and then the value to part in the variable as here, for example, my new variable and. 109 00:09:47,190 --> 00:10:01,440 Uh, here and for example, hacking is the most valuable, valuable skill set in the twenty first century. 110 00:10:04,810 --> 00:10:05,080 You. 111 00:10:06,730 --> 00:10:13,460 So this assigns a string to the variable mine environment, so to see the value in the VAT in that variable 112 00:10:13,460 --> 00:10:22,180 and use the Echo Command and the dollar content symbol to with the variable name, as we did earlier 113 00:10:22,180 --> 00:10:22,570 here. 114 00:10:22,900 --> 00:10:25,570 My new variable, which? 115 00:10:26,510 --> 00:10:32,720 As you can see, they're just like our system environment variables, user defined variables must be 116 00:10:32,720 --> 00:10:35,600 exported to persist to new sessions. 117 00:10:36,260 --> 00:10:45,680 So if you want to delete these new moneyball. or any variable use that on set on onset myname variable 118 00:10:46,760 --> 00:10:47,060 here. 119 00:10:47,330 --> 00:10:48,710 So now it's equal. 120 00:10:48,800 --> 00:10:51,440 And as you can see, we have no new variable pitch. 121 00:10:52,260 --> 00:10:52,670 So. 122 00:10:53,910 --> 00:11:00,240 You mean, because we deal with this variable with Ansett command and have to, uh, press and equal 123 00:11:00,330 --> 00:11:02,040 for printing to tomorrow? 124 00:11:02,160 --> 00:11:05,130 We can't see it because there is no credibility here. 125 00:11:05,160 --> 00:11:07,020 After all, setting this variable. 126 00:11:07,950 --> 00:11:13,830 So lastly, you might find in white, I'm afraid it was foreign, but it's worth getting to know them 127 00:11:13,980 --> 00:11:21,420 so they control how your working environment in Linux looks, acts and feels so you can manage these 128 00:11:21,420 --> 00:11:28,140 variables to tell in your environment, to your needs by changing them, exporting them and even creating 129 00:11:28,140 --> 00:11:30,720 your own, as we did in this case. 130 00:11:31,140 --> 00:11:35,760 So in some cases, these they may be useful for covering your tracks as a hacker.