1
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2
00:00:05,330 --> 00:00:07,870
>> SPIKA: Hadi sasa, ni uwezekano
kwamba wengi wa mipango yako

3
00:00:07,870 --> 00:00:10,170
kuwa kidogo ephemeral.

4
00:00:10,170 --> 00:00:13,310
Kukimbia mpango kama Mario au tamaa.

5
00:00:13,310 --> 00:00:17,350
Ni haina kitu, ni labda papo
user kwa baadhi ya habari,

6
00:00:17,350 --> 00:00:20,400
magazeti baadhi pato kwa screen,
lakini kisha wakati mpango wako juu,

7
00:00:20,400 --> 00:00:23,252
kuna kweli hakuna ushahidi pale
ilikuwa milele kukimbia katika nafasi ya kwanza.

8
00:00:23,252 --> 00:00:25,960
I mean, hakika, unaweza kuwa na kushoto
ni wazi katika dirisha terminal,

9
00:00:25,960 --> 00:00:29,770
lakini kama wewe wazi screen yako, kuna
kweli hakuna ushahidi kwamba kuwepo.

10
00:00:29,770 --> 00:00:33,720
Hatuna njia ya kuhifadhi
Maelezo ya kuendelea, habari

11
00:00:33,720 --> 00:00:36,890
kwamba ipo baada wetu
Mpango huo kusimamishwa mbio,

12
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au tuna si hadi hatua hii.

13
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Kwa bahati nzuri ingawa, c gani
kutupatia uwezo

14
00:00:41,490 --> 00:00:44,220
kufanya hivyo kwa kutekeleza
kitu kinachoitwa

15
00:00:44,220 --> 00:00:48,330
file, muundo kwamba kimsingi
inawakilisha faili kwamba itakuwa mara mbili

16
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click kwenye kompyuta yako, kama wewe ni
kutumika graphical mazingira mtumiaji.

17
00:00:53,826 --> 00:00:55,700
Kwa ujumla wakati wa kufanya kazi
na c, sisi ni kweli

18
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kwenda kufanya kazi kwa
kuyatumia kwa files-- faili stars--

19
00:00:59,965 --> 00:01:02,090
isipokuwa kwa kidogo
wakati sisi majadiliano juu ya wanandoa

20
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ya kazi ambayo
kazi na kuyatumia file.

21
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Huna haja ya kuwa na kweli kuchimbwa
pia kina ndani ya kuyatumia uelewa

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wenyewe.

23
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Kuna kidogo kidogo teeny
ambapo sisi majadiliano juu yao,

24
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lakini kwa ujumla faili kuyatumia na
kuyatumia, wakati yanayohusiana,

25
00:01:18,090 --> 00:01:20,290
si hasa kitu kimoja.

26
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>> Sasa je, mimi maana wakati
Nasema data kuendelea?

27
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Ni nini data kuendelea?

28
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Kwa nini sisi huduma kuhusu hilo?

29
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Kusema, kwa mfano, kwamba
wewe ni mbio mpango

30
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au umefanya kuandikwa upya
Mpango hiyo ni mchezo,

31
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na unataka kuweka wimbo
ya yote ya hatua ya mtumiaji

32
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ili labda kama kitu fulani kitaenda vibaya,
unaweza mapitio faili baada ya mchezo.

33
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Hiyo ni nini maana sisi wakati sisi
majadiliano juu ya data kuendelea.

34
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>> Katika mwendo wa mbio yako
mpango, faili ni kuundwa.

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Na wakati mpango wako
kimesimama kukimbia,

36
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faili kwamba bado lipo kwenye mfumo wako.

37
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Na tunaweza kuangalia ni na kuchunguza yake.

38
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Na hivyo mpango huo itakuwa kuweka
tumemuumba baadhi ya data ya kudumu,

39
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data kuwepo baada ya mpango
ina kumaliza mbio.

40
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>> Sasa wote wa kazi hizo kuwa kazi
na kujenga files na kufanyia

41
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nao kwa njia mbalimbali
wanaishi katika kiwango io.h,

42
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ambayo ni header faili kwamba
umefanya uwezekano kuwa pauni

43
00:02:08,210 --> 00:02:10,910
ikiwa ni pamoja na juu ya pretty
mengi yote ya programu yako

44
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kwa sababu ina moja ya
kazi zaidi na manufaa kwa ajili yetu,

45
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printf, ambayo pia inakuwezesha
anaishi katika kiwango io.h.

46
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Hivyo huna haja ya chupa pamoja na
mafaili yoyote ya ziada pengine

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ili kufanya kazi na kuyatumia file.

48
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>> Sasa kila mmoja faili pointer kazi,
au kila faili moja I / O, pembejeo pato

49
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kazi, anapokea kama moja
ya vigezo wake au pembejeo

50
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faili pointer isipokuwa
kwa moja, fopen, ambayo

51
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ni nini kutumia ili kupata faili
pointer katika nafasi ya kwanza.

52
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Lakini baada ya umefanya kufunguliwa
faili na kupata kuyatumia faili,

53
00:02:41,010 --> 00:02:43,510
unaweza kisha kupita yao kama
hoja kwa kazi mbalimbali

54
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sisi ni kwenda kuzungumza kuhusu
leo, pamoja na wengine wengi

55
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ili uweze kufanya kazi na mafaili.

56
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>> Hivyo kuna sita pretty
kawaida ndio msingi

57
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kwamba sisi ni kwenda kuzungumza kuhusu leo.

58
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fopen na rafiki yake
kazi fclose, fgetc

59
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na rafiki utendaji wake wa kazi fputc,
na fread na rafiki yake kazi,

60
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fwrite.

61
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Basi hebu kupata haki ndani yake.

62
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>> fopen-- ni nini nini?

63
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Naam, ni kufungua faili na
anatoa faili pointer hiyo,

64
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ili uweze kisha kutumia kwamba
faili pointer kama hoja

65
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kwa yoyote ya faili wengine I / O kazi.

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Jambo muhimu zaidi
kukumbuka kwa fopen

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ni kwamba baada ya kufunguliwa
faili au alitoa wito kama moja hapa,

68
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unahitaji kuangalia kuhakikisha
kwamba pointer kwamba got nyuma

69
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si sawa kwa null.

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Kama si watched video juu ya
kuyatumia, hii inaweza kufanya akili.

71
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Lakini kama wewe kujaribu dereference na
pointer null wanakumbuka,

72
00:03:35,639 --> 00:03:38,180
Mpango wako pengine kuteswa
segmentation [inaudible].

73
00:03:38,180 --> 00:03:40,540
Tunataka kuhakikisha kwamba sisi
got halali pointer nyuma.

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Idadi kubwa ya muda sisi
waliopata pointer halali nyuma

75
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na haitakuwa tatizo.

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>> Hivyo ni jinsi gani sisi kufanya wito kwa fopen?

77
00:03:46,760 --> 00:03:48,051
Inaonekana pretty kiasi kama hii.

78
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Faili nyota ptr-- ptr kuwa kurefusha maisha
jina kwa ajili ya faili pointer fopen

79
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na sisi kupita katika mambo mawili, jina la faili
na uendeshaji tunataka kufanya.

80
00:03:57,300 --> 00:04:01,690
Hivyo tuwe na wito kwamba inaonekana kama
Haya faili nyota PTR 1 ni sawa na fopen

81
00:04:01,690 --> 00:04:04,040
file1.txt.

82
00:04:04,040 --> 00:04:07,020
Na uendeshaji nimekuwa waliochaguliwa ni r.

83
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>> Hivyo unafikiri nini r ni hapa?

84
00:04:08,639 --> 00:04:11,180
Je, ni aina ya mambo sisi
kuwa na uwezo wa kufanya ili mafaili?

85
00:04:11,180 --> 00:04:13,760

86
00:04:13,760 --> 00:04:17,500
Hivyo r ni operesheni kwamba sisi
kuchagua wakati tunataka kusoma faili.

87
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Hivyo tunataka kimsingi wakati
sisi kufanya wito kama huu

88
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kuwa kupata wenyewe faili pointer
kiasi kwamba tunaweza kisha kusoma taarifa

89
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kutoka file1.txt.

90
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>> Vile vile, tunaweza kufungua faili 2.txt
kwa maandishi na ili tuweze kupita ptr2,

91
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faili pointer nimekuwa kuundwa hapa,
kama hoja kwa kazi yoyote ambayo

92
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anaandika habari kwa file.

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Na sawa na kuandika, kuna
pia ni chaguo append,.

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Tofauti kati
kuandika na appending

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kuwa kwamba wakati wewe kuandika na faili,
kama wewe kufanya wito kwa fopen kwa kuandika

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na faili kwamba tayari ipo, ni
kwenda overwrite faili nzima.

97
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Ni kwenda kuanza
mwanzoni kabisa,

98
00:04:56,510 --> 00:04:58,820
kufuta taarifa zote
hiyo ni tayari pale.

99
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>> Lakini ikiwa kuufungua kwa appending,
itakuwa kwenda hadi mwisho wa faili

100
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kama kuna tayari asilia katika
au maelezo ndani yake,

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na itakuwa kisha kuanza
kuandika kutoka huko.

102
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Hivyo si kupoteza yoyote ya
Maelezo umefanya kosa kabla.

103
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Kama unataka kuandika au append
aina ya inategemea hali hiyo.

104
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Lakini pengine utasikia kujua nini
operesheni haki ni wakati unakuja.

105
00:05:16,840 --> 00:05:18,020
Hivyo hiyo ni fopen.

106
00:05:18,020 --> 00:05:18,930
>> Je kuhusu fclose?

107
00:05:18,930 --> 00:05:21,600
Naam, pretty tu, fclose
tu anapokea faili pointer.

108
00:05:21,600 --> 00:05:24,000
Na kama unaweza kutarajia,
ni kufunga faili hilo.

109
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Na mara moja tumekuwa imefungwa file, hatuwezi
kufanya faili tena I / O kazi,

110
00:05:29,270 --> 00:05:31,420
kusoma au kuandika, juu ya faili hilo.

111
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Tuna upya kufungua
faili wakati mwingine ili

112
00:05:36,444 --> 00:05:38,610
kuendelea kufanya kazi na
hivyo kwa kutumia I / O kazi.

113
00:05:38,610 --> 00:05:41,520
Njia Hivyo fclose sisi ni kosa
kufanya kazi na faili hii.

114
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Na wote tunahitaji kupitisha katika ni
jina la faili pointer.

115
00:05:44,690 --> 00:05:50,010
Kadhalika wanandoa slides iliyopita, sisi
fopened faili 1 nukta maandishi kwa ajili ya kusoma

116
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na sisi kupewa kwamba
faili pointer ptr1.

117
00:05:52,854 --> 00:05:55,020
Sasa tumekuwa aliamua tuko
amefanya kusoma kutoka faili hilo.

118
00:05:55,020 --> 00:05:56,561
Hatuna haja ya kufanya lolote zaidi na hayo.

119
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Tunaweza tu fclose ptr1.

120
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Na vile vile, hakuweza sisi
fclose wale wengine.

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Sawa.

122
00:06:02,450 --> 00:06:03,700
Hivyo hiyo ni kufungua na kufunga.

123
00:06:03,700 --> 00:06:05,780
Hayo ni msingi miwili
kuanzia shughuli.

124
00:06:05,780 --> 00:06:08,050
>> Sasa tunataka kweli
kufanya baadhi ya mambo ya kuvutia,

125
00:06:08,050 --> 00:06:11,940
na kazi ya kwanza kwamba tutaweza
kuona kwamba kufanya hivyo ni fgetc--

126
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faili kupata tabia.

127
00:06:14,110 --> 00:06:17,350
Hiyo ni nini fgetc ujumla
ingekuwa kutafsiri kwa.

128
00:06:17,350 --> 00:06:20,190
Lengo lake katika maisha ni
kusoma tabia ijayo,

129
00:06:20,190 --> 00:06:22,079
au kama hii ni yako sana
wito wa kwanza fgetc

130
00:06:22,079 --> 00:06:23,870
kwa ajili ya faili fulani,
tabia ya kwanza.

131
00:06:23,870 --> 00:06:26,210
Lakini basi baada ya hapo,
kupata moja ijayo,

132
00:06:26,210 --> 00:06:31,500
tabia iliyofuata ya faili kwamba,
na maduka katika kutofautiana tabia.

133
00:06:31,500 --> 00:06:34,490
Kama tumefanya hapa,
char ch sawa na fgetc,

134
00:06:34,490 --> 00:06:36,389
kupita kwa jina la faili pointer.

135
00:06:36,389 --> 00:06:38,180
Tena, ni sana
muhimu hapa kukumbuka

136
00:06:38,180 --> 00:06:41,430
kwamba ili kuwa na
operesheni hii kufanikiwa,

137
00:06:41,430 --> 00:06:45,690
faili pointer yenyewe must've
imefunguliwa kwa ajili ya kusoma.

138
00:06:45,690 --> 00:06:50,589
Hatuwezi kusoma tabia kutoka faili
pointer kwamba sisi kufunguliwa kwa maandishi.

139
00:06:50,589 --> 00:06:52,630
Hivyo hiyo ni moja ya
mapungufu ya fopen, sawa?

140
00:06:52,630 --> 00:06:55,470
Tuna kuzuia
wenyewe kwa kufanya tu

141
00:06:55,470 --> 00:06:57,710
operesheni moja kwa moja faili pointer.

142
00:06:57,710 --> 00:07:00,220
Kama sisi alitaka kusoma na
kuandika kutoka faili moja,

143
00:07:00,220 --> 00:07:03,840
tunataka kuwa wazi viwili tofauti
kuyatumia faili file-- sawa

144
00:07:03,840 --> 00:07:05,670
moja kwa ajili ya kusoma, moja kwa maandishi.

145
00:07:05,670 --> 00:07:08,400
>> Hivyo tena, sababu tu
Mimi kuleta kuwa hadi sasa ni

146
00:07:08,400 --> 00:07:11,920
kwa sababu kama sisi ni kwenda kupiga simu
kwa fgetc, kwamba faili pointer must've

147
00:07:11,920 --> 00:07:14,172
imefunguliwa kwa ajili ya kusoma.

148
00:07:14,172 --> 00:07:15,880
Na kisha pretty tu,
zote tunahitaji kufanya

149
00:07:15,880 --> 00:07:17,546
ni kupita kwa jina la faili pointer.

150
00:07:17,546 --> 00:07:21,060
Hivyo Char ch sawa na fgetc ptr1.

151
00:07:21,060 --> 00:07:23,200
>> Hiyo inaenda kupata sisi
character-- ijayo

152
00:07:23,200 --> 00:07:25,575
au tena, kama hii ni mara ya kwanza
wakati tumekuwa alifanya wito huu,

153
00:07:25,575 --> 00:07:29,750
character-- kwanza wa chochote
faili zimeelekezwa kwa na ptr1.

154
00:07:29,750 --> 00:07:32,210
Kumbuka kwamba hiyo ilikuwa ya faili 1 nukta asilia.

155
00:07:32,210 --> 00:07:36,490
Ni itabidi kupata tabia ya kwanza ya kwamba
na tutaweza kuhifadhi katika ch kutofautiana.

156
00:07:36,490 --> 00:07:37,941
Pretty moja kwa moja.

157
00:07:37,941 --> 00:07:40,190
Hivyo tumekuwa tu inaonekana katika tatu
kazi na tayari sisi

158
00:07:40,190 --> 00:07:43,070
wanaweza kufanya kitu pretty nadhifu.

159
00:07:43,070 --> 00:07:46,320
>> Hivyo kama sisi kuchukua uwezo huu
ya kupata tabia

160
00:07:46,320 --> 00:07:48,943
na sisi kitanzi it-- hivyo sisi
kuendelea kupata wahusika

161
00:07:48,943 --> 00:07:51,390
kutoka faili tena na
tena na over-- sasa sisi

162
00:07:51,390 --> 00:07:54,500
Unaweza kusoma kila moja
tabia ya faili.

163
00:07:54,500 --> 00:07:58,670
Na kama sisi magazeti kila tabia
mara baada ya sisi kusoma,

164
00:07:58,670 --> 00:08:01,960
sisi sasa kusoma kutoka faili na
kuchapishwa yaliyomo yake kwa screen.

165
00:08:01,960 --> 00:08:05,610
Tumekuwa ufanisi concatenated
kwamba faili kwenye screen.

166
00:08:05,610 --> 00:08:09,670
Na kwamba ni nini
Linux amri paka gani.

167
00:08:09,670 --> 00:08:13,250
>> Kama aina paka katika jina la faili, ni
magazeti nje yaliyomo yote

168
00:08:13,250 --> 00:08:15,160
ya faili katika terminal dirisha yako.

169
00:08:15,160 --> 00:08:19,010
Na hivyo hii kitanzi kidogo hapa,
mistari mitatu tu ya maadili,

170
00:08:19,010 --> 00:08:23,270
lakini kwa ufanisi marudio
Linux amri paka.

171
00:08:23,270 --> 00:08:25,210
Hivyo syntax hii huenda
kuangalia kidogo weird,

172
00:08:25,210 --> 00:08:26,670
lakini hapa ni nini kinatokea hapa.

173
00:08:26,670 --> 00:08:31,460
Wakati ch sawa na fgetc, PTR si
sawa na EOF-- ni Mouthful nzima,

174
00:08:31,460 --> 00:08:34,669
lakini hebu kuvunja chini tu
hivyo ni wazi juu ya syntax.

175
00:08:34,669 --> 00:08:37,169
Nimekuwa kuimarishwa ni
kwa ajili ya nafasi,

176
00:08:37,169 --> 00:08:39,049
ingawa ni kidogo
syntactically gumu.

177
00:08:39,049 --> 00:08:41,194
>> Hivyo sehemu hii katika kijani haki
sasa, nini ni kufanya?

178
00:08:41,194 --> 00:08:42,860
Naam, hiyo ni fgetc yetu wito, sawa?

179
00:08:42,860 --> 00:08:44,530
Tumeona kwamba kabla.

180
00:08:44,530 --> 00:08:49,500
Ni kupata moja
tabia kutoka faili.

181
00:08:49,500 --> 00:08:53,220
Kisha sisi kulinganisha kwamba
tabia dhidi EOF.

182
00:08:53,220 --> 00:08:57,470
EOF ni thamani maalum kwamba
inavyoelezwa katika kiwango io.h, ambayo

183
00:08:57,470 --> 00:08:59,390
Huu ndio mwisho wa faili tabia.

184
00:08:59,390 --> 00:09:03,450
Hivyo kimsingi nini kitatokea
ni kitanzi hii itakuwa kusoma tabia,

185
00:09:03,450 --> 00:09:07,445
kulinganisha kwa EOF,
mwisho wa faili tabia.

186
00:09:07,445 --> 00:09:10,070
Kama hawana mechi, hivyo tuna si
kufikiwa mwisho wa file,

187
00:09:10,070 --> 00:09:11,490
tutaweza magazeti kwamba tabia nje.

188
00:09:11,490 --> 00:09:13,740
Kisha tutaweza kurudi
mwanzo wa kitanzi tena.

189
00:09:13,740 --> 00:09:18,310
Tutaweza kupata tabia, kuangalia
dhidi EOF, magazeti ya nje, na kadhalika

190
00:09:18,310 --> 00:09:21,094
na kadhalika na kadhalika,
looping kupitia kwa njia ambayo

191
00:09:21,094 --> 00:09:22,760
mpaka tumekuwa kufikiwa mwisho wa faili.

192
00:09:22,760 --> 00:09:24,593
Na kisha kwa hatua hiyo,
tutakuwa na kuchapishwa

193
00:09:24,593 --> 00:09:26,210
nje yaliyomo yote ya faili.

194
00:09:26,210 --> 00:09:29,450
Hivyo tena, tumekuwa tu kuonekana
fopen, fclose, na fgetc

195
00:09:29,450 --> 00:09:34,950
na tayari tunaweza kurudia
Linux wastaafu amri.

196
00:09:34,950 --> 00:09:38,850
>> Kama nilivyosema mwanzoni,
tulikuwa na fgetc na fputc,

197
00:09:38,850 --> 00:09:41,860
na fputc alikuwa rafiki
kazi ya fgetc.

198
00:09:41,860 --> 00:09:44,880
Na hivyo, kama unaweza kufikiria,
ni kuandika sawa.

199
00:09:44,880 --> 00:09:49,440
Ni inaruhusu sisi kuandika
tabia moja na faili.

200
00:09:49,440 --> 00:09:53,290
>> Tena, caveat kuwa, tu
kama ilivyokuwa kwa fgetc, faili

201
00:09:53,290 --> 00:09:56,660
kwamba sisi ni kuandika kwa must've wamekuwa
kufunguliwa kwa maandishi au kwa appending.

202
00:09:56,660 --> 00:10:00,820
Kama sisi kujaribu na kutumia fputc kwenye faili la
kwamba tumekuwa kufunguliwa kwa ajili ya kusoma,

203
00:10:00,820 --> 00:10:02,760
tunakwenda kuteseka
kidogo ya makosa.

204
00:10:02,760 --> 00:10:04,440
Lakini wito ni pretty rahisi.

205
00:10:04,440 --> 00:10:08,000
mji mkuu fputc ptr2, kila
hiyo ni kwenda kufanya ni ni

206
00:10:08,000 --> 00:10:12,040
kwenda kuandika barua
ndani ya kwenye faili 2 nukta

207
00:10:12,040 --> 00:10:14,760
maandishi, ambayo ilikuwa jina ya
faili kwamba sisi kufunguliwa na kupewa

208
00:10:14,760 --> 00:10:17,280
pointer ptr2.

209
00:10:17,280 --> 00:10:20,430
Hivyo sisi ni kwenda kuandika
A mji mkuu na faili 2 nukta asilia.

210
00:10:20,430 --> 00:10:24,592
Na tutaweza kuandika mshangao
uhakika na faili 3 nukta

211
00:10:24,592 --> 00:10:27,330
maandishi, ambayo ilikuwa alisema kwa ptr3.

212
00:10:27,330 --> 00:10:29,730
Hivyo tena, pretty moja kwa moja hapa.

213
00:10:29,730 --> 00:10:32,727
>> Lakini sasa tunaweza kufanya kitu kingine.

214
00:10:32,727 --> 00:10:34,560
Tuna mfano huu
tulikuwa tu kwenda juu

215
00:10:34,560 --> 00:10:38,950
juu ya kuwa na uwezo wa kuiga paka
Linux amri, moja kwamba Prints nje

216
00:10:38,950 --> 00:10:40,500
screen.

217
00:10:40,500 --> 00:10:43,510
Naam, sasa kwamba tuna uwezo
kusoma wahusika kutoka mafaili

218
00:10:43,510 --> 00:10:46,590
na kuandika herufi ya mafaili,
kwa nini sio sisi tu mbadala kwamba

219
00:10:46,590 --> 00:10:50,720
wito kwa printf kwa mwito wa fputc.

220
00:10:50,720 --> 00:10:54,090
>> Na sasa tumekuwa kurudiwa cp,
msingi sana Linux amri

221
00:10:54,090 --> 00:10:59,100
kwamba kuongelea njia ya muda mrefu
iliyopita katika Linux amri video.

222
00:10:59,100 --> 00:11:01,070
Tumekuwa ufanisi
duplicated kwamba haki hapa.

223
00:11:01,070 --> 00:11:04,790
Sisi ni kusoma tabia na kisha tuko
kuandika kwamba tabia ya faili jingine.

224
00:11:04,790 --> 00:11:07,660
Kusoma kutoka faili moja, kuandika
hadi nyingine, tena na tena

225
00:11:07,660 --> 00:11:11,350
na tena mpaka sisi kugonga EOF.

226
00:11:11,350 --> 00:11:14,250
Sisi tumepewa mwishoni mwa
faili sisi ni kujaribu nakala kutoka.

227
00:11:14,250 --> 00:11:18,500
Na kwa kuwa tutaweza wameandika zote
ya wahusika tunahitaji faili

228
00:11:18,500 --> 00:11:19,500
kwamba sisi ni kuandika kwa.

229
00:11:19,500 --> 00:11:24,270
Hivyo hii ni cp, Linux na nakala ya amri.

230
00:11:24,270 --> 00:11:26,550
>> Mwanzoni kabisa mwa
video hii, nilikuwa na caveat

231
00:11:26,550 --> 00:11:29,840
kwamba tunataka kuzungumza
kidogo kuhusu kuyatumia.

232
00:11:29,840 --> 00:11:32,480
Hapa ni hasa ambapo tuko
kwenda kuzungumza kuhusu kuyatumia

233
00:11:32,480 --> 00:11:34,800
pamoja na faili kuyatumia.

234
00:11:34,800 --> 00:11:37,870
Hivyo kazi hii inaonekana aina ya inatisha.

235
00:11:37,870 --> 00:11:39,120
Ni got vigezo kadhaa.

236
00:11:39,120 --> 00:11:40,430
Kuna mengi kinachoendelea hapa.

237
00:11:40,430 --> 00:11:42,760
Kuna mengi ya tofauti
rangi na maandiko.

238
00:11:42,760 --> 00:11:47,100
Lakini kwa kweli, ni tu
toleo la kurefusha maisha ya fgetc

239
00:11:47,100 --> 00:11:50,110
ambayo inaruhusu sisi kupata yoyote
Kiasi cha habari.

240
00:11:50,110 --> 00:11:53,560
Ni inaweza kuwa kidogo ufanisi kama sisi ni
kupata wahusika mmoja kwa wakati,

241
00:11:53,560 --> 00:11:55,770
iterating kupitia faili
tabia moja kwa wakati mmoja.

242
00:11:55,770 --> 00:12:00,230
Je, si ni kuwa nicer kupata
100 kwa wakati mmoja au 500 kwa wakati mmoja?

243
00:12:00,230 --> 00:12:03,250
>> Naam, fread na rafiki yake kazi
fwrite, ambayo tutaweza majadiliano juu ya

244
00:12:03,250 --> 00:12:05,490
katika pili, kuruhusu sisi kufanya tu.

245
00:12:05,490 --> 00:12:08,480
Tunaweza kusoma kiasi holela
cha habari kutoka faili

246
00:12:08,480 --> 00:12:10,290
na sisi kuhifadhi mahali fulani kwa muda.

247
00:12:10,290 --> 00:12:12,980
Badala ya kuwa na uwezo wa tu
fit katika kutofautiana moja,

248
00:12:12,980 --> 00:12:15,790
tupate haja ya kuhifadhi katika safu.

249
00:12:15,790 --> 00:12:19,980
Na hivyo, sisi kupita katika nne
hoja kwa fread-- pointer

250
00:12:19,980 --> 00:12:23,940
kwa eneo ambapo tuko
kwenda kuhifadhi habari,

251
00:12:23,940 --> 00:12:29,180
jinsi kubwa kila kitengo cha habari
itakuwa, vitengo ngapi wa habari

252
00:12:29,180 --> 00:12:35,192
tunataka kupata, na kutoka
ambayo faili tunataka kupata yao.

253
00:12:35,192 --> 00:12:37,150
Pengine ni bora mfano
kwa mfano hapa.

254
00:12:37,150 --> 00:12:41,640
Basi hebu kusema kwamba sisi kutangaza
safu ya 10 integers.

255
00:12:41,640 --> 00:12:45,080
Tumekuwa tu alitangaza juu ya
stack kiholela int arr 10.

256
00:12:45,080 --> 00:12:46,970
Hivyo hiyo ni pretty moja kwa moja.

257
00:12:46,970 --> 00:12:51,970
Sasa nini sisi ni kufanya ingawa ni
frecall ni sisi ni kusoma ukubwa wa int

258
00:12:51,970 --> 00:12:54,180
mara 10 ka wa habari.

259
00:12:54,180 --> 00:12:59,040
Ukubwa wa int kuwa four-- hiyo ni
ukubwa wa integer katika c.

260
00:12:59,040 --> 00:13:02,790
>> Hivyo nini sisi ni kufanya ni sisi ni kusoma
40 ka thamani ya habari

261
00:13:02,790 --> 00:13:05,850
kutoka faili alisema kwa PTR.

262
00:13:05,850 --> 00:13:08,600
Na sisi ni hifadhi wale
40 ka mahali fulani

263
00:13:08,600 --> 00:13:12,080
ambapo tumetenga
40 ka thamani ya kumbukumbu.

264
00:13:12,080 --> 00:13:15,970
Kwa bahati nzuri, tumekuwa tayari amefanya hivyo kwa
kutangaza arr, kwamba safu haki pale.

265
00:13:15,970 --> 00:13:19,770
Kuwa ni uwezo wa kufanya
10 manne-Byte vipande.

266
00:13:19,770 --> 00:13:22,860
Hivyo kwa jumla, inaweza kuendesha 40
ka thamani ya habari.

267
00:13:22,860 --> 00:13:26,540
Na sisi sasa ni kusoma ka 40
cha habari kutoka faili,

268
00:13:26,540 --> 00:13:30,330
na sisi ni hifadhi hiyo katika arr.

269
00:13:30,330 --> 00:13:35,470
>> Kumbuka kutoka video kwenye kuyatumia kwamba
jina la safu, kama vile arr,

270
00:13:35,470 --> 00:13:38,370
ni kweli tu pointer
kwa kipengele yake ya kwanza.

271
00:13:38,370 --> 00:13:43,680
Hivyo wakati sisi kupita katika arr huko, sisi
ni, kwa kweli, kupita katika pointer.

272
00:13:43,680 --> 00:13:46,120
>> Vile vile tunaweza kufanya Haya
sisi si lazima

273
00:13:46,120 --> 00:13:51,200
haja ya kuokoa buffer yetu juu ya stack.

274
00:13:51,200 --> 00:13:54,990
Tunaweza pia dynamically kutenga
a buffer kama hii, kwa kutumia malloc.

275
00:13:54,990 --> 00:13:57,340
Kumbuka, wakati sisi
dynamically kutenga kumbukumbu,

276
00:13:57,340 --> 00:14:00,550
sisi ni kuokoa juu ya
chungu, si stack.

277
00:14:00,550 --> 00:14:02,110
Lakini bado ni buffer.

278
00:14:02,110 --> 00:14:06,810
>> Bado, katika kesi hii, ni
kuikopesha 640 ka wa habari

279
00:14:06,810 --> 00:14:09,230
kwa sababu mara mbili inachukua hadi ka nane.

280
00:14:09,230 --> 00:14:11,570
Na sisi ni kuuliza kwa 80 miongoni mwao.

281
00:14:11,570 --> 00:14:13,770
Tunataka kuwa na nafasi
kushikilia 80 mara mbili.

282
00:14:13,770 --> 00:14:17,210
Hivyo mara 80 8 ni 640 ka habari.

283
00:14:17,210 --> 00:14:21,880
Na kwamba wito kwa fread ni
kukusanya 640 ka wa habari

284
00:14:21,880 --> 00:14:27,770
kutoka faili alisema kwa
ptr na hifadhi hiyo sasa katika arr2.

285
00:14:27,770 --> 00:14:32,770
>> Sasa tunaweza pia kutibu fread
kama wito kwa fgetc.

286
00:14:32,770 --> 00:14:37,140
Katika kesi hiyo, sisi ni kujaribu tu
kupata tabia moja kutoka faili.

287
00:14:37,140 --> 00:14:40,070
Na hatuna haja
safu kushikilia tabia.

288
00:14:40,070 --> 00:14:43,170
Tunaweza tu kuhifadhi katika
tabia kutofautiana.

289
00:14:43,170 --> 00:14:46,390
>> Kukamata, ingawa, ni kwamba
wakati sisi tu kutofautiana,

290
00:14:46,390 --> 00:14:50,290
tunahitaji kupitisha katika
pepe ya kwamba kutofautiana

291
00:14:50,290 --> 00:14:52,550
kwa sababu wanakumbuka kwamba
kwanza hoja kwa fread

292
00:14:52,550 --> 00:14:59,210
ni pointer eneo na kumbukumbu
ambapo tunataka kuhifadhi habari.

293
00:14:59,210 --> 00:15:01,550
Tena, jina la
safu ni pointer.

294
00:15:01,550 --> 00:15:04,200
Hivyo hatuna haja ya kufanya ampersand safu.

295
00:15:04,200 --> 00:15:07,270
Lakini c, tabia c
hapa, ni si safu.

296
00:15:07,270 --> 00:15:08,390
Ni tu kutofautiana.

297
00:15:08,390 --> 00:15:11,840
Na hivyo tunahitaji kupitisha
ampersand c kuonyesha

298
00:15:11,840 --> 00:15:15,350
kwamba hiyo ni anwani ambapo tunataka
kuhifadhi Byte hii moja wa habari,

299
00:15:15,350 --> 00:15:20,479
tabia hii moja kwamba
sisi ni kukusanya kutoka PTR.

300
00:15:20,479 --> 00:15:22,270
Fwrite-- nitakwenda kupitia
hii kidogo zaidi

301
00:15:22,270 --> 00:15:25,440
quickly-- ni kiasi pretty
halisi sawa na fread

302
00:15:25,440 --> 00:15:27,720
isipokuwa ni kwa ajili ya kuandika
badala ya kusoma, tu

303
00:15:27,720 --> 00:15:31,610
kama other-- tulikuwa na wazi
na karibu, kupata tabia,

304
00:15:31,610 --> 00:15:32,530
kuandika tabia.

305
00:15:32,530 --> 00:15:35,040
Sasa ni kupata holela
Kiasi cha habari,

306
00:15:35,040 --> 00:15:37,170
haki holela kiasi cha habari.

307
00:15:37,170 --> 00:15:39,790
Hivyo tu kama kabla, tunaweza
safu ya integers 10

308
00:15:39,790 --> 00:15:43,210
ambapo tayari tuna
habari kuhifadhiwa, labda.

309
00:15:43,210 --> 00:15:46,580
>> Ilikuwa pengine baadhi mstari wa kanuni
kuwa anatakiwa kwenda kati ya hizi mbili

310
00:15:46,580 --> 00:15:49,990
ambapo mimi kujaza ARR na
kitu ya maana.

311
00:15:49,990 --> 00:15:51,880
Mimi kujaza kwa 10 integers tofauti.

312
00:15:51,880 --> 00:15:54,920
Na badala yake, ni nini mimi nina
kufanya ni kuandika kutoka arr

313
00:15:54,920 --> 00:15:58,600
na kukusanya taarifa kutoka arr.

314
00:15:58,600 --> 00:16:02,390
Na mimi nina kuchukua habari ambazo
na kuweka katika faili.

315
00:16:02,390 --> 00:16:05,410
>> Hivyo badala ya kuwa kutokana na
faili buffer,

316
00:16:05,410 --> 00:16:08,790
tuko sasa kwenda kutoka
buffer na faili.

317
00:16:08,790 --> 00:16:10,580
Hivyo ni tu kinyume.

318
00:16:10,580 --> 00:16:16,680
Hivyo tena, tu kama kabla, tunaweza
pia kuwa lundo chunk ya kumbukumbu

319
00:16:16,680 --> 00:16:19,600
kwamba tumekuwa dynamically
zilizotengwa na kusoma kutoka kuwa

320
00:16:19,600 --> 00:16:21,570
na kuandika kuwa na faili.

321
00:16:21,570 --> 00:16:24,900
>> Na sisi pia kuwa kutofautiana moja
uwezo wa kufanya byte moja

322
00:16:24,900 --> 00:16:27,200
ya habari, kama vile tabia.

323
00:16:27,200 --> 00:16:29,830
Lakini tena, tunahitaji kupitisha katika
pepe ya kwamba kutofautiana

324
00:16:29,830 --> 00:16:31,840
wakati tunataka kusoma kutoka humo.

325
00:16:31,840 --> 00:16:35,280
Ili tuweze kuandika maelezo
tunaona katika anwani hiyo

326
00:16:35,280 --> 00:16:39,050
na faili pointer, ptr.

327
00:16:39,050 --> 00:16:41,630
>> Kuna kura ya wengine
faili kubwa I / O kazi

328
00:16:41,630 --> 00:16:44,650
kwamba kufanya mambo mbalimbali badala
ndio tumekuwa aliyesema kuhusu leo.

329
00:16:44,650 --> 00:16:46,450
Michache ya watoto
unaweza kupata manufaa

330
00:16:46,450 --> 00:16:50,840
ni fgets na fputs,
ambayo ni sawa

331
00:16:50,840 --> 00:16:56,190
ya fgetc na fputc lakini kwa kusoma
kamba moja kutoka faili.

332
00:16:56,190 --> 00:16:59,020
Badala ya tabia moja,
itakuwa kusoma kamba nzima.

333
00:16:59,020 --> 00:17:02,940
fprintf, ambayo kimsingi inaruhusu
kutumia printf kuandika na faili.

334
00:17:02,940 --> 00:17:05,619
Hivyo tu kama unaweza kufanya
kutofautiana badala ya kutumia

335
00:17:05,619 --> 00:17:09,900
asilimia placeholders i na
asilimia d, na kadhalika, na printf

336
00:17:09,900 --> 00:17:14,690
unaweza vile vile kuchukua
printf kamba na magazeti kitu

337
00:17:14,690 --> 00:17:16,800
kama kwamba kwa file.

338
00:17:16,800 --> 00:17:20,720
>> fseek-- kama una DVD player
ni mfano mimi matumizi ya kawaida here--

339
00:17:20,720 --> 00:17:23,109
ni aina ya kama kwa kutumia yako
rewind na ya haraka mbele

340
00:17:23,109 --> 00:17:25,819
vifungo kuweza kuzunguka sinema.

341
00:17:25,819 --> 00:17:28,369
Vile vile, unaweza kuzunguka faili.

342
00:17:28,369 --> 00:17:30,250
Moja ya mambo ndani ya
kwamba muundo faili

343
00:17:30,250 --> 00:17:34,270
kuwa c inajenga kwa ajili yenu ni kiashiria
ya ambapo wewe ni katika faili.

344
00:17:34,270 --> 00:17:36,420
Ni wewe saa sana
mwanzo, katika Byte sifuri?

345
00:17:36,420 --> 00:17:39,290
Ni wewe saa Byte 100,
Byte 1000, na kadhalika?

346
00:17:39,290 --> 00:17:44,340
Unaweza kutumia fseek kiholela kusonga
kuwa kiashiria mbele au nyuma.

347
00:17:44,340 --> 00:17:46,744
>> Na ftell, tena
sawa na mchezaji DVD,

348
00:17:46,744 --> 00:17:49,660
Ni kama saa kidogo kwamba anaelezea
jinsi dakika na sekunde wewe wengi

349
00:17:49,660 --> 00:17:52,480
ni katika sinema fulani.

350
00:17:52,480 --> 00:17:56,990
Vile vile, ftell anaelezea jinsi
wengi ka wewe ni katika faili.

351
00:17:56,990 --> 00:18:00,210
feof ni toleo la tofauti
ya kuchunguza kama wameweza

352
00:18:00,210 --> 00:18:01,700
kufikiwa mwisho wa faili.

353
00:18:01,700 --> 00:18:03,600
Na ferror ni kazi
kwamba unaweza kutumia

354
00:18:03,600 --> 00:18:06,959
kuchunguza kama kitu ina
gone kazi kibaya na faili.

355
00:18:06,959 --> 00:18:08,750
Tena, hii ni
scratching ya uso.

356
00:18:08,750 --> 00:18:12,730
Bado kuna mengi zaidi ya faili I / O
kazi katika io.h. kiwango

357
00:18:12,730 --> 00:18:16,620
Lakini hii pengine kupata wewe
kuanza kufanya kazi na kuyatumia file.

358
00:18:16,620 --> 00:18:17,640
Mimi nina Doug Lloyd.

359
00:18:17,640 --> 00:18:19,750
Hii ni cs50.

360
00:18:19,750 --> 00:18:21,669