1 00:00:00,940 --> 00:00:04,850 In this lecture we will play with challenging get optical month. 2 00:00:05,200 --> 00:00:10,080 Great script called Get off the stage and start with Shaban 3 00:00:14,250 --> 00:00:15,110 from the beginning. 4 00:00:15,110 --> 00:00:24,960 We can print all arguments given to our script do not assign it represents all arguments. 5 00:00:25,800 --> 00:00:33,510 Now we into of the variable output of get optical month where we will have some short positional parameters. 6 00:00:33,750 --> 00:00:40,650 So we need to use and dash 0 followed by let's say parameter a which will have optional argument and 7 00:00:40,680 --> 00:00:47,280 if it is optional we need to provide two columns parameter B must have some argument that's why we want 8 00:00:47,270 --> 00:00:53,160 to call on and parameters see the e won't have any arguments that's why we don't specify any call on 9 00:00:53,250 --> 00:00:55,440 after them now right. 10 00:00:55,450 --> 00:01:01,590 Dash dash long for the long parameters and there we will have parameter file with optional argument 11 00:01:01,860 --> 00:01:10,590 parameter name with the required argument and parameter a help without any argument at the end of forget 12 00:01:10,680 --> 00:01:18,110 command we need to specify arguments which are going to be passed so degradation space dollar sign and 13 00:01:19,530 --> 00:01:27,630 by ls set command we are changing initial arguments and for being sure the change really happened we 14 00:01:27,630 --> 00:01:32,700 can print all arguments after they were passed would get up to command 15 00:01:43,740 --> 00:01:52,680 so just to recap how get opt works and get up command returns past arguments in order to pass them we 16 00:01:52,680 --> 00:02:00,390 need to specify to get opt command what parameters we are taking into account if we are specifying short 17 00:02:00,390 --> 00:02:08,220 parameters that means parameters starting with dash for example dash a we need to specify them after 18 00:02:08,250 --> 00:02:09,650 this all parameter. 19 00:02:10,800 --> 00:02:18,450 So here we have parameter a followed by two columns which means that parameter 8 can be followed by 20 00:02:18,480 --> 00:02:27,180 optional argument then we have parameter B with column that means with required argument then we have 21 00:02:27,180 --> 00:02:37,080 parameters c d and e which don't take any arguments Evie in our script want to have long parameters 22 00:02:37,230 --> 00:02:46,100 as for example designated file we need to specify them after David's long parameter of course we need 23 00:02:46,100 --> 00:02:53,740 to tell to get up to command what arguments we want to pass and we can do that by using digital age 24 00:02:53,810 --> 00:02:55,940 space the latter sign at 25 00:02:59,330 --> 00:03:07,910 So now we'll do the same we did with our script file check it as if we need to process pass arguments 26 00:03:08,810 --> 00:03:15,740 one by one so while number of arguments is greater than zero 0 exit could do better inside while loop 27 00:03:17,360 --> 00:03:27,440 if first argument is a we can print barometer a selected 28 00:03:31,440 --> 00:03:39,180 so if we choose def a if if A is first argument print parameter a 29 00:03:43,160 --> 00:03:50,680 selected with argument dollar assigned to. 30 00:03:50,930 --> 00:03:56,340 Now we need to get rid of parameter and argument by to shift commands 31 00:04:02,490 --> 00:04:10,920 or we can just override shift tool it does the same thing as to shift commands 32 00:04:14,080 --> 00:04:17,360 for option B and we will bring something similar. 33 00:04:17,380 --> 00:04:18,400 So just copy. 34 00:04:18,400 --> 00:04:20,380 Option A and edit it 35 00:04:36,070 --> 00:04:41,020 for Option C we will print Option C selected 36 00:04:45,210 --> 00:04:52,960 or parameters c selected and we will get rid of this parameter by shift command. 37 00:04:55,080 --> 00:04:56,600 No need for another shift command. 38 00:04:56,640 --> 00:04:59,730 As if it didn't specify column after this parameter. 39 00:04:59,730 --> 00:05:02,920 So no argument is expected here. 40 00:05:02,970 --> 00:05:10,830 Option D and E will be pretty much the same so just copy Option C and edit it. 41 00:05:23,290 --> 00:05:34,370 In case long option parameter a file was used we will print parameter file selected wait 42 00:05:36,860 --> 00:05:37,480 argument 43 00:05:41,010 --> 00:05:47,140 dollar assigned to our assigned to represent that argument that date value of the argument. 44 00:05:47,900 --> 00:05:51,570 And of course she could do to get rid of arguments. 45 00:05:51,590 --> 00:05:54,560 An optional argument. 46 00:05:54,690 --> 00:06:01,570 Sorry I said you only to get rid of parameters and optional argument in case no argument was selected 47 00:06:01,660 --> 00:06:07,220 as it is optional though are assigned to will be an empty string the same. 48 00:06:07,240 --> 00:06:10,150 Of course we can do for name parameter 49 00:06:19,690 --> 00:06:24,080 shift too and we have. 50 00:06:24,100 --> 00:06:31,390 But I mean the help so for parameter help we can print parameter to help selected 51 00:06:35,300 --> 00:06:40,220 and there is no argument so just only one shift. 52 00:06:44,050 --> 00:06:47,230 And for cases something else was selected 53 00:06:52,490 --> 00:07:05,260 we can just posit that option of a puzzle does pass that argument and it's all we can now say with the 54 00:07:05,270 --> 00:07:06,090 script. 55 00:07:11,670 --> 00:07:13,370 Ground execute permissions 56 00:07:16,140 --> 00:07:17,090 and we can run it. 57 00:07:18,390 --> 00:07:20,810 Firstly drive it Dash CDE 58 00:07:29,140 --> 00:07:42,490 and we see that it transform this city into dash C dash D and dash e gate. 59 00:07:42,540 --> 00:07:53,910 Now we can do some little change we can add parameter a followed by optional argument without any space. 60 00:07:55,760 --> 00:08:00,490 And an optional argument is called optional in my case. 61 00:08:00,490 --> 00:08:01,710 And we see that. 62 00:08:01,780 --> 00:08:02,460 Get up. 63 00:08:02,470 --> 00:08:08,470 Pass it to dash a and optional argument which is great. 64 00:08:08,500 --> 00:08:09,040 It works. 65 00:08:11,580 --> 00:08:15,170 If you don't specify arguments for parameter a. 66 00:08:16,050 --> 00:08:24,070 We see that parameter a was selected with non existing argument. 67 00:08:24,090 --> 00:08:26,630 Now let's say at option B 68 00:08:29,490 --> 00:08:33,730 followed by argument call required. 69 00:08:33,750 --> 00:08:41,610 Because in Get up come on to B wrote one column after parameter B and the long option file followed 70 00:08:41,610 --> 00:08:53,930 by equal sign optional and add also long option name parameter with argument required. 71 00:08:55,970 --> 00:08:58,640 And we see that it was part as well 72 00:09:01,630 --> 00:09:13,030 in case that we didn't specify required argument it can be for example for a parameter name we got at 73 00:09:13,030 --> 00:09:17,760 or from get opt command option name requires an argument. 74 00:09:19,530 --> 00:09:29,350 Now if we didn't specify optional argument for a parameter file we see that parameter file was selected 75 00:09:29,360 --> 00:09:30,920 with no argument. 76 00:09:30,920 --> 00:09:39,530 Great but what happens if the after parameter a file put a value something of value something wasn't 77 00:09:39,530 --> 00:09:45,320 kept as file parameter needs equal sign of an optional argument is given. 78 00:09:45,320 --> 00:09:56,050 If we go back to the script we can change it a little bit we will edit section for case something else 79 00:09:56,050 --> 00:10:18,580 was given as an argument and we will write what was given what argument was given. 80 00:10:19,160 --> 00:10:27,510 Now around the script again and we see that we are printing two dashes which marks the end of arguments 81 00:10:27,510 --> 00:10:35,560 passed by get up and then we see something which is argument which wasn't which wasn't passed by. 82 00:10:35,650 --> 00:10:39,760 Up and Get Up but part can be really challenging. 83 00:10:39,930 --> 00:10:46,080 It has own rules which needs to be followed but if you play with it more you will get used to it. 84 00:10:46,860 --> 00:10:50,870 Now it's up to you and the situation what method to choose. 85 00:10:50,910 --> 00:10:58,800 You can take care of scripts arguments yourself as we did for file check script or you can use quite 86 00:10:58,860 --> 00:11:06,330 easy get opt which has the limitation of not processing along parameters or you can use more advanced 87 00:11:06,660 --> 00:11:07,140 get opt.