1 00:00:07,060 --> 00:00:08,420 [Powered by Google Translate] Tommy: Katika video hii, tutaweza kujifunza kuhusu 2 00:00:08,420 --> 00:00:10,140 imetuma na mabomba. 3 00:00:10,140 --> 00:00:12,780 Hadi sasa, tumekuwa kutumia kazi like printf kwa 4 00:00:12,780 --> 00:00:15,590 pato data terminal na kazi kama GetString 5 00:00:15,590 --> 00:00:17,520 kuruhusu user kutoa pembejeo kwa wetu 6 00:00:17,520 --> 00:00:19,490 programu kwa kutumia keyboard. 7 00:00:19,490 --> 00:00:21,880 Hebu haraka kuangalia mpango kwamba anapata mstari wa 8 00:00:21,880 --> 00:00:25,960 pembejeo kutoka kwa mtumiaji na kisha matokeo yake. 9 00:00:25,960 --> 00:00:28,990 >> On line 7, sisi ni uvuvio mtumiaji kwa kamba, na 10 00:00:28,990 --> 00:00:31,680 kisha juu ya mstari 8, sisi ni uchapishaji nyuma nje. 11 00:00:31,680 --> 00:00:35,220 Hebu kukusanya na kuendesha programu yetu. 12 00:00:35,220 --> 00:00:35,900 Mkuu. 13 00:00:35,900 --> 00:00:37,620 kamba sisi zinazotolewa yalirejewa nyuma 14 00:00:37,620 --> 00:00:39,170 na sisi katika terminal. 15 00:00:39,170 --> 00:00:42,110 Hii ilitokea kwa sababu kazi printf aliandika kwa 16 00:00:42,110 --> 00:00:46,220 mkondo kuitwa kiwango nje, au s-t-d-nje. 17 00:00:46,220 --> 00:00:49,230 Wakati kitu imeandikwa kwa stdout, ni kwa default 18 00:00:49,230 --> 00:00:51,110 visas kwa wastaafu. 19 00:00:51,110 --> 00:00:53,720 >> Basi hiyo ni vizuri wote na nzuri, lakini kile kama, badala ya tu 20 00:00:53,720 --> 00:00:57,700 kuonyesha kamba, sisi alitaka kuokoa kwa faili? 21 00:00:57,700 --> 00:01:00,470 Kwa mfano, sisi kutaka kukumbuka nini hasa wetu 22 00:01:00,470 --> 00:01:04,450 mpango alifanya wakati sisi akampa pembejeo fulani baadaye. 23 00:01:04,450 --> 00:01:07,270 Mmoja mkabala itakuwa kufanya hili katika mpango wetu C, kwa kutumia 24 00:01:07,270 --> 00:01:09,680 baadhi ya kazi maalum kwa ajili ya kuandika kwa files kwamba tutaweza 25 00:01:09,680 --> 00:01:11,270 kuona katika video nyingine. 26 00:01:11,270 --> 00:01:13,260 Hata rahisi, ingawa, itakuwa namna fulani 27 00:01:13,260 --> 00:01:16,090 redirect stdout na faili. 28 00:01:16,090 --> 00:01:19,780 Kwa njia hiyo, wakati printf anaandika kwa stdout, yaliyomo mapenzi 29 00:01:19,780 --> 00:01:21,720 kuandikwa na faili kuliko 30 00:01:21,720 --> 00:01:23,410 visas kwa wastaafu. 31 00:01:23,410 --> 00:01:26,690 Tunaweza kufanya hivyo tu kwa kuongeza ishara kubwa zaidi-kuliko, ikifuatiwa 32 00:01:26,690 --> 00:01:30,820 na jina la faili, kwa amri ya sisi kutumia ili kutekeleza mpango wetu. 33 00:01:30,820 --> 00:01:34,730 >> Hivyo, badala ya utekelezaji / redirect., Tunaweza 34 00:01:34,730 --> 00:01:38,880 kukimbia /. redirect, ikifuatiwa na zaidi ya ishara, ikifuatiwa na 35 00:01:38,880 --> 00:01:41,530 filename, kama file.txt. 36 00:01:41,530 --> 00:01:44,290 Hebu kuona nini kinatokea. 37 00:01:44,290 --> 00:01:45,130 OK. 38 00:01:45,130 --> 00:01:48,470 Taarifa kwamba wakati huu, hakuna kitu visas terminal, 39 00:01:48,470 --> 00:01:50,290 lakini hatuna iliyopita yaliyomo wetu 40 00:01:50,290 --> 00:01:52,040 C mpango wakati wote. 41 00:01:52,040 --> 00:01:56,090 Hebu sasa kuchunguza yaliyomo ya saraka hii na ls. 42 00:01:56,090 --> 00:01:56,630 >> Wote haki. 43 00:01:56,630 --> 00:02:00,840 Sisi sasa una faili mpya katika saraka yetu iitwayo file.txt, 44 00:02:00,840 --> 00:02:03,640 ambayo ni jina la faili sisi hutolewa wakati sisi mbio zetu 45 00:02:03,640 --> 00:02:05,050 Redirect mpango. 46 00:02:05,050 --> 00:02:08,020 Hebu kufungua file.txt. 47 00:02:08,020 --> 00:02:11,840 Na hapa, tunaweza kuona kwamba stdout nje ya redirect ilikuwa 48 00:02:11,840 --> 00:02:15,550 imeandikwa na faili inayoitwa file.txt. 49 00:02:15,550 --> 00:02:18,470 Basi hebu kukimbia amri ya awali tena, lakini kusambaza 50 00:02:18,470 --> 00:02:20,075 mbalimbali pembejeo wakati huu. 51 00:02:25,140 --> 00:02:25,900 Sawa. 52 00:02:25,900 --> 00:02:28,205 Hebu tuangalie file.txt sasa. 53 00:02:31,070 --> 00:02:34,580 >> Tunaweza kuona hapa kwamba faili imekuwa overwritten, hivyo wetu 54 00:02:34,580 --> 00:02:37,120 pembejeo awali si huko tena. 55 00:02:37,120 --> 00:02:40,280 Kama sisi badala wanataka append na faili hili, kuweka mpya 56 00:02:40,280 --> 00:02:43,600 pembejeo chini ya yaliyomo ya faili zilizopo, tunaweza 57 00:02:43,600 --> 00:02:46,800 kutumia wawili ishara kubwa zaidi-kuliko badala ya moja tu. 58 00:02:46,800 --> 00:02:48,050 Hebu jaribu hilo. 59 00:02:52,160 --> 00:02:57,910 Sasa, kama sisi kufungua file.txt tena, tunaweza kuona wote wa wetu 60 00:02:57,910 --> 00:02:59,580 pembejeo mistari. 61 00:02:59,580 --> 00:03:02,180 Katika baadhi ya matukio, sisi kutaka kuondokana yoyote 62 00:03:02,180 --> 00:03:03,850 pato la programu yetu. 63 00:03:03,850 --> 00:03:06,450 Badala ya kuandika pato kwa faili na kisha kufuta 64 00:03:06,450 --> 00:03:09,310 faili wakati sisi ni kufanyika kwa hiyo, tunaweza kuandika maalum 65 00:03:09,310 --> 00:03:12,360 faili inayoitwa / Dev / null. 66 00:03:12,360 --> 00:03:15,160 Wakati chochote imeandikwa kwa / dev/null-- 67 00:03:15,160 --> 00:03:16,960 au tu kwa kifupi devnull - 68 00:03:16,960 --> 00:03:18,950 ni moja kwa moja kuondolewa. 69 00:03:18,950 --> 00:03:23,290 Hivyo kufikiria devnull kama shimo nyeusi kwa data zako. 70 00:03:23,290 --> 00:03:26,070 >> Hivyo sasa tumeona jinsi ishara kubwa zaidi kuliko unaweza redirect 71 00:03:26,070 --> 00:03:29,610 stdout, hebu angalia jinsi gani tunaweza kuelekeza kiwango katika - 72 00:03:29,610 --> 00:03:31,250 s-au t-d-katika - 73 00:03:31,250 --> 00:03:33,550 analog ya stdout. 74 00:03:33,550 --> 00:03:36,010 Wakati kazi kama printf kuandika mkondo kuitwa 75 00:03:36,010 --> 00:03:40,500 stdout, GetString na majukumu sawa kusoma kutoka mkondo 76 00:03:40,500 --> 00:03:43,770 kuitwa stdin, ambayo, kwa default, ni mkondo wa 77 00:03:43,770 --> 00:03:46,290 wahusika typed katika keyboard. 78 00:03:46,290 --> 00:03:50,010 Tunaweza redirect stdin kutumia chini ya ishara, ikifuatiwa 79 00:03:50,010 --> 00:03:51,370 na jina la faili. 80 00:03:51,370 --> 00:03:54,000 Sasa, badala ya uvuvio mtumiaji kwa ajili ya pembejeo katika 81 00:03:54,000 --> 00:03:57,870 terminal, programu hiyo kufungua faili sisi maalum na kutumia 82 00:03:57,870 --> 00:03:59,790 mistari yake kama pembejeo. 83 00:03:59,790 --> 00:04:02,620 >> Hebu kuona nini kinatokea. 84 00:04:02,620 --> 00:04:03,280 Mkuu. 85 00:04:03,280 --> 00:04:07,590 mstari wa kwanza wa file.txt limechapishwa kwa terminal 86 00:04:07,590 --> 00:04:10,160 kwa sababu sisi ni wito GetString mara moja. 87 00:04:10,160 --> 00:04:13,170 Kama tulikuwa na mwingine wito kwa GetString katika mpango wetu, 88 00:04:13,170 --> 00:04:16,149 line ya pili ya file.txt ingekuwa kutumika kama 89 00:04:16,149 --> 00:04:17,990 pembejeo kwa wito huo. 90 00:04:17,990 --> 00:04:21,050 Tena, sisi si iliyopita C mpango wetu wakati wote. 91 00:04:21,050 --> 00:04:23,620 Sisi ni tu kubadilisha jinsi sisi kukimbia. 92 00:04:23,620 --> 00:04:27,080 Na pia kumbuka, sisi si itaelekezwa stdout wakati huu, 93 00:04:27,080 --> 00:04:28,970 hivyo pato la programu hiyo bado 94 00:04:28,970 --> 00:04:31,040 kuonyeshwa katika terminal. 95 00:04:31,040 --> 00:04:33,500 Tunaweza, bila shaka, redirect wote stdin 96 00:04:33,500 --> 00:04:37,320 na stdout kama hii. 97 00:04:37,320 --> 00:04:43,550 Sasa, file2.txt ina mstari wa kwanza wa file.txt. 98 00:04:43,550 --> 00:04:46,140 >> Hivyo, kwa kutumia kampuni za hizi, tumekuwa na uwezo wa kusoma na 99 00:04:46,140 --> 00:04:48,130 kuandika kutoka Nakala files. 100 00:04:48,130 --> 00:04:51,890 Sasa, hebu angalia jinsi gani tunaweza kutumia pato la programu moja kama 101 00:04:51,890 --> 00:04:54,710 pembejeo kwa mpango mwingine. 102 00:04:54,710 --> 00:04:56,650 Hivyo hapa ni rahisi mwingine C mpango mimi 103 00:04:56,650 --> 00:05:00,190 kuwa hapa aitwaye hello.c. 104 00:05:00,190 --> 00:05:02,617 Kama unaweza kuona, hii tu matokeo "Hi 105 00:05:02,617 --> 00:05:04,430 huko "! kwa mtumiaji. 106 00:05:04,430 --> 00:05:08,890 Kama nataka redirect kwa kutumia pembejeo kama pato la Hello - 107 00:05:08,890 --> 00:05:10,190 mpango mwingine - 108 00:05:10,190 --> 00:05:13,920 Mimi nilikuwa kwanza redirect stdout ya hello faili inayoitwa 109 00:05:13,920 --> 00:05:18,960 input.txt, kisha kuelekeza stdin ya redirect kwa hiyo 110 00:05:18,960 --> 00:05:21,190 faili - input.txt. 111 00:05:21,190 --> 00:05:26,730 Hivyo siwezi kufanya / hujambo> input.txt.. 112 00:05:26,730 --> 00:05:28,810 Vyombo vya habari Enter nitafanya hili. 113 00:05:28,810 --> 00:05:31,910 Ikifuatiwa na. / Redirect < 114 00:05:31,910 --> 00:05:35,270 input.txt, na nitafanya hivyo. 115 00:05:35,270 --> 00:05:38,290 Hivyo tunaweza kufupisha hii kidogo kwa semicolon, ambayo inaruhusu 116 00:05:38,290 --> 00:05:41,360 sisi kukimbia amri mbili au zaidi juu ya mstari huo. 117 00:05:41,360 --> 00:05:47,920 Hivyo naweza kusema,. / Hujambo> input.txt, semicolon, 118 00:05:47,920 --> 00:05:50,580 . / Redirect 00:05:56,740 >> Hivyo hii kazi, lakini bado anahisi pretty inelegant. 120 00:05:56,740 --> 00:05:59,530 I mean, je kweli tunahitaji hii Nakala mwangalizi faili hilo 121 00:05:59,530 --> 00:06:02,520 muhimu tena baada ya redirect anaendesha? 122 00:06:02,520 --> 00:06:05,780 Kwa bahati nzuri, tunaweza kuepuka hili ziada Nakala faili kwa kutumia nini 123 00:06:05,780 --> 00:06:07,220 aitwaye bomba. 124 00:06:07,220 --> 00:06:13,740 Nikisema, / hujambo |.. / Redirect, basi stdout ya 125 00:06:13,740 --> 00:06:15,310 mpango wa kushoto - 126 00:06:15,310 --> 00:06:16,740 katika kesi hii, hujambo - 127 00:06:16,740 --> 00:06:18,970 zitatumika kama pembejeo kwa kiwango 128 00:06:18,970 --> 00:06:20,370 mpango juu ya haki. 129 00:06:20,370 --> 00:06:24,850 Katika kesi hii, na kuelekeza. Basi hebu kukimbia hii. 130 00:06:24,850 --> 00:06:25,930 >> Kuna sisi kwenda. 131 00:06:25,930 --> 00:06:30,080 Tunaweza kuona kwamba pato la hujambo ilitumika kama pembejeo 132 00:06:30,080 --> 00:06:31,520 kwa kuelekeza. 133 00:06:31,520 --> 00:06:34,890 Kwa stringing amri pamoja kwa kutumia mabomba, sisi kuunda nini 134 00:06:34,890 --> 00:06:38,120 aitwaye bomba, tangu pato yetu kimsingi ni kusonga 135 00:06:38,120 --> 00:06:40,590 kupitia kwenye mlolongo wa amri. 136 00:06:40,590 --> 00:06:43,570 Kutumia mabomba, tunaweza kufanya baadhi ya mambo ya baridi bila wanaohitaji 137 00:06:43,570 --> 00:06:45,870 kuandika code yoyote wakati wote. 138 00:06:45,870 --> 00:06:48,760 Kwa mfano, hebu kusema tunataka kujua jinsi wengi files ni 139 00:06:48,760 --> 00:06:50,630 ndani ya saraka hii. 140 00:06:50,630 --> 00:06:55,200 Kutumia bomba, tunaweza kuchanganya amri ls na WC - 141 00:06:55,200 --> 00:06:56,460 au wordcount - 142 00:06:56,460 --> 00:06:57,850 amri. 143 00:06:57,850 --> 00:07:02,230 Ls itakuwa pato kila faili katika saraka stdout, na 144 00:07:02,230 --> 00:07:08,040 WC kutuambia jinsi mistari wengi wamepewa hiyo kupitia stdin. 145 00:07:08,040 --> 00:07:12,440 Hivyo, kama sisi kusema ls | WC-l - 146 00:07:12,440 --> 00:07:16,800 kusambaza-l bendera ya WC kuiambia kuhesabu mistari - 147 00:07:16,800 --> 00:07:19,260 tunaweza kuona hasa jinsi wengi files ni 148 00:07:19,260 --> 00:07:21,940 katika saraka ya sasa. 149 00:07:21,940 --> 00:07:24,570 >> Basi hebu tuangalie mfano mmoja zaidi. 150 00:07:24,570 --> 00:07:27,740 Mimi hapa faili inayoitwa students.txt, 151 00:07:27,740 --> 00:07:29,600 pamoja na orodha ya majina. 152 00:07:29,600 --> 00:07:32,730 Hata hivyo, majina haya si katika amri yoyote yote, na inaonekana 153 00:07:32,730 --> 00:07:34,850 kama majina machache yamerudiwa. 154 00:07:34,850 --> 00:07:38,510 Tunachotaka ni orodha ya majina ya kipekee katika alfabeti 155 00:07:38,510 --> 00:07:42,550 ili, kuokolewa na faili inayoitwa final.txt. 156 00:07:42,550 --> 00:07:45,210 Tunaweza, bila shaka, kuandika mpango C kufanya hili kwa ajili yetu. 157 00:07:45,210 --> 00:07:46,560 Lakini ni kwenda kupata unnecessarily 158 00:07:46,560 --> 00:07:48,560 tata pretty haraka. 159 00:07:48,560 --> 00:07:51,740 Hebu badala yake kutumia mabomba na baadhi ya kujengwa katika zana-kutatua 160 00:07:51,740 --> 00:07:53,300 tatizo hili. 161 00:07:53,300 --> 00:07:57,760 >> Jambo la kwanza tunahitaji kufanya ni kusoma students.txt faili. 162 00:07:57,760 --> 00:08:00,530 amri paka itakuwa kufanya tu. 163 00:08:00,530 --> 00:08:03,230 Itakuwa kusoma katika faili maalum na kuandika 164 00:08:03,230 --> 00:08:05,750 yaliyomo yake kwa stdout. 165 00:08:05,750 --> 00:08:07,570 Baada tumekuwa kusoma faili maandishi, tutaweza 166 00:08:07,570 --> 00:08:09,490 unataka kutatua majina. 167 00:08:09,490 --> 00:08:12,510 amri aina inaweza kushughulikia hili kwa ajili yetu. 168 00:08:12,510 --> 00:08:16,830 Panga itakuwa pato mstari hutolewa kupitia stdin kwa stdout 169 00:08:16,830 --> 00:08:19,310 ili Iliyopangwa. 170 00:08:19,310 --> 00:08:23,450 Ili ugavi yaliyomo ya students.txt kwa 171 00:08:23,450 --> 00:08:29,600 stdin aina ya, tunaweza kutumia bomba kwa kuchanganya na paka na aina. 172 00:08:29,600 --> 00:08:34,440 Hivyo siwezi nitafanya paka students.txt | aina na 173 00:08:34,440 --> 00:08:35,640 waandishi wa habari kuingia. 174 00:08:35,640 --> 00:08:39,309 Na sasa, tunaona yaliyomo katika students.txt 175 00:08:39,309 --> 00:08:40,909 alfabeti utaratibu. 176 00:08:40,909 --> 00:08:42,860 >> Basi hebu kuongeza mwingine amri - 177 00:08:42,860 --> 00:08:44,730 uniq, au kipekee - 178 00:08:44,730 --> 00:08:46,230 kwenye bomba yetu. 179 00:08:46,230 --> 00:08:49,810 Kama unaweza guess, uniq, wakati hutolewa mlolongo sorted ya 180 00:08:49,810 --> 00:08:53,650 mistari kupitia stdin, itakuwa pato mistari ya kipekee. 181 00:08:53,650 --> 00:08:56,910 Hivyo basi, tuna paka students.txt 182 00:08:56,910 --> 00:09:00,040 | Aina | uniq. 183 00:09:00,040 --> 00:09:03,330 Hatimaye, tunaweza kuokoa pato la bomba hadi 184 00:09:03,330 --> 00:09:09,090 faili kupitia paka students.txt | aina | uniq 185 00:09:09,090 --> 00:09:12,440 > Final.txt. 186 00:09:12,440 --> 00:09:16,260 Hivyo, kama sisi kufungua final.txt, tuna nini hasa sisi walikuwa 187 00:09:16,260 --> 00:09:17,270 kuangalia kwa: 188 00:09:17,270 --> 00:09:20,180 orodha ya majina ya kipekee katika herufi, 189 00:09:20,180 --> 00:09:22,150 kuokolewa na faili asilia. 190 00:09:22,150 --> 00:09:26,020 Kwa njia, sisi pia inaweza kuwa alisema aina < 191 00:09:26,020 --> 00:09:32,290 students.txt | uniq> final.txt kufanya hasa 192 00:09:32,290 --> 00:09:35,400 kitu kimoja, kutumia kila moja ya kampuni za tumeona katika 193 00:09:35,400 --> 00:09:36,580 hii video. 194 00:09:36,580 --> 00:09:39,540 >> Jina langu ni Tommy, na hii ni CS50.