1 00:00:00,800 --> 00:00:08,030 In this lecture started with grating script called Get up it's not an age where we will practice handling 2 00:00:08,090 --> 00:00:10,470 of positional parameters. 3 00:00:10,790 --> 00:00:19,760 Let's say that you want parameters A and B with some arguments and parameters c and d without no arguments 4 00:00:20,120 --> 00:00:21,400 without any arguments. 5 00:00:21,440 --> 00:00:31,380 So we need to put call on after a and after B to tell get out that arguments are needed here. 6 00:00:33,300 --> 00:00:43,560 So why get up to command will be through all screwed we'll be executing body of while loop so one time 7 00:00:43,560 --> 00:00:46,340 more after a get up to command. 8 00:00:46,340 --> 00:00:53,380 We are placing positional parameters as parameters A and B require argument. 9 00:00:53,480 --> 00:00:56,870 We need to specify gone after them. 10 00:00:56,870 --> 00:01:01,570 So we see a go on B equal on CB. 11 00:01:01,940 --> 00:01:03,910 After a C or after D. 12 00:01:03,950 --> 00:01:14,130 There is no call on that means that those positional parameters don't need any argument body of a while 13 00:01:14,130 --> 00:01:19,060 loop will be executed when output of a get opts command is through. 14 00:01:19,080 --> 00:01:26,850 That means of an output often get opts command has exit status zero and then all positional parameters 15 00:01:26,940 --> 00:01:32,200 are processed exit status of get up to command is non-zero. 16 00:01:32,730 --> 00:01:39,730 And that means that body of available want won't be processed. 17 00:01:39,820 --> 00:01:45,050 Now we need to ask what is the current parameter to process. 18 00:01:45,130 --> 00:01:48,280 We will check it with case statement 19 00:01:58,020 --> 00:02:10,170 in case the parameter to process is parameter a visual print parameter a barometer 20 00:02:12,510 --> 00:02:16,350 a weight argument 21 00:02:20,170 --> 00:02:23,870 dollar sign up tag 22 00:02:26,800 --> 00:02:31,890 of Arc is variable which has the value of required argument. 23 00:02:31,890 --> 00:02:38,750 Note that the way to get out we didn't check for a parameter starting with the dash get off it handle 24 00:02:38,760 --> 00:02:40,570 this automatically. 25 00:02:40,590 --> 00:02:52,270 So here we didn't check for a positional parameter a dash a but only for a In case B was selected. 26 00:02:52,540 --> 00:02:54,270 We'll print parameter B 27 00:02:59,930 --> 00:03:01,310 parameter B 28 00:03:04,850 --> 00:03:09,750 selected with argument which has value of variable arc 29 00:03:19,380 --> 00:03:20,390 okay. 30 00:03:21,050 --> 00:03:30,510 So in the case Siebel selected we can just print that parameter C was selected. 31 00:03:30,510 --> 00:03:32,040 That is not nothing more 32 00:03:37,650 --> 00:03:46,830 so parameter C selected here remember that we did a news column after parameter C so there is no argument 33 00:03:46,920 --> 00:03:55,050 expected and we can do the same for the parameter. 34 00:03:55,050 --> 00:03:55,380 The 35 00:03:59,920 --> 00:04:06,960 so echo parameter be selected 36 00:04:12,530 --> 00:04:14,190 now the script is done. 37 00:04:14,660 --> 00:04:20,760 We have set what should be done in case specific parameter is selected. 38 00:04:20,840 --> 00:04:24,960 So now the tricky question. 39 00:04:25,070 --> 00:04:31,910 Have you noticed that in the script we are not using keyboard shift for moving away arguments. 40 00:04:32,150 --> 00:04:33,830 We don't need to do that. 41 00:04:33,950 --> 00:04:40,310 Get out in the background has note how many positional parameters of error process and for that specific 42 00:04:40,310 --> 00:04:40,720 reason. 43 00:04:40,730 --> 00:04:46,160 Get ups uses opt in variable we discussed in Del lecture. 44 00:04:46,160 --> 00:04:53,210 This is if I get up it is so easy we don't need to take care of shifting argument if a or is handled 45 00:04:53,240 --> 00:04:54,720 by get opt. 46 00:04:54,830 --> 00:05:01,960 We only need to specify parameters and say what to do when those parameters vary. 47 00:05:01,960 --> 00:05:02,450 Used 48 00:05:06,230 --> 00:05:09,380 we can now just save and exit the script 49 00:05:12,080 --> 00:05:13,640 ground exit permissions 50 00:05:18,680 --> 00:05:21,530 and we can handle it. 51 00:05:21,620 --> 00:05:29,240 Let's say with parameter a wait um argument call required 52 00:05:33,730 --> 00:05:46,810 with parameter B with argument also required and with Dash C D which means both parameters see. 53 00:05:47,200 --> 00:05:57,280 So you'll see that even we put def S.D. it passes both parameters as if we use the C and dash D gate. 54 00:05:57,780 --> 00:06:04,740 Now let's play a little more I can add another a parameter without any argument and we see error message 55 00:06:05,490 --> 00:06:08,110 option requires an argument. 56 00:06:08,110 --> 00:06:16,880 Great now we can both dash DC as a first parameters 57 00:06:20,520 --> 00:06:28,800 and if you hit on it it disperses without any issue you can now play with positional parameters yourself 58 00:06:29,160 --> 00:06:31,770 and I will wait for you in the next lecture.