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>> SPIKA 1: Hebu kuandika mpango huo
anapata kamba kutoka kwa mtumiaji bila

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kutumia CS50 Library
kazi GetString.

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Kwa kufanya hivyo, tutaweza kwenda mbele na kutumia
scanf, kazi ambayo GetString

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kazi kweli anatumia
chini ya kofia.

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Lakini mimi nina kwenda kufanya hili kwa makusudi
katika buggy njia.

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Mimi nina kwenda kufanya katika njia ambayo nadhani
itakuwa haki, lakini zinageuka kuwa

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dhana yangu kwenda
kabisa, kabisa kiujanja.

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Na kwa kweli, hatari kabisa.

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Kwa sababu mende kama moja mimi nina kuhusu
kufanya inaweza kutumiwa na wapinzani

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kama kwamba mashine yako au mpango wako
inaweza kuchukuliwa juu ya uwezekano.

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>> Hebu tuanze kama ifuatavyo.

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Kwanza hebu kutangaza kamba yetu,
inayojulikana sasa kama nyota char,

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na kuiita s.

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Hebu ijayo haraka user kwa kamba,
kama na "kamba tafadhali." Na

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hebu sasa kupata kamba kutoka kwa mtumiaji
kutumia scanf, unquote quote, "% s." Katika

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maneno mengine, hebu kuwajulisha scanf kwamba sisi
wala kwa kweli kutarajia kupata string

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kutoka kwa mtumiaji.

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>> Lakini sasa tunahitaji kuwaambia scanf
nyingine jambo moja -

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mahali pa kuweka kamba kwamba
user hutoa.

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Naam, mimi nina kwenda kabisa tu kuanza
na comma s, inayobainisha kwamba Ningependa

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scanf kuweka kamba huko.

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Mimi nina ijayo kwenda magazeti nje kitu
kama printf "shukrani kwa% s

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backslash n comma. "Na kama siku zote, mimi nina
kwenda kupita katika kamba, s.

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Sasa hebu kuokoa, kukusanya, na kukimbia hii
mpango, na kuona kama tunaweza si kutumika

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tatizo mimi alikadiria.

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>> Kufanya scanf-1.

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./scanf-1.

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Kamba tafadhali.

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Hebu kutoa kitu kama, "hello."
"Asante kwa null." Hmm, si kwamba

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nini nilikuwa kutarajia.

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Hivyo nini kinaendelea hapa?

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>> Naam, ni zamu nje kwa sababu sisi alitangaza
s kama nyota char lakini hatukuwa

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kweli kuhifadhiwa s katika barua pepe ya
chunk halisi ya kumbukumbu, scanf hakuwa

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mahali popote kuweka kamba
kwamba mtumiaji typed in

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Hakika, kama user walikuwa sasa aina katika
kamba muda mrefu zaidi kuliko "hello,"

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kwa mfano mistari kadhaa ya maandishi au
aya kadhaa ya maandishi, ni kabisa

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iwezekanavyo ili tupate kutumika
kinachojulikana segmentation kosa.

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>> Kwa sababu scanf si kwenda kujua kwamba
Mimi si kweli kuweka anwani

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ndani ya s.

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Badala yake, kwenda kuona baadhi ya thamani
katika s, mfano baadhi ya bits ambayo inaweza

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vizuri sana kuwa na thamani ya takataka,
pale tu kwa bahati.

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Na scanf bado ni kwenda kujaribu kuandika
kamba user kwa anwani hiyo,

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hata kama ni takataka thamani, ambayo
inaweza kweli kutumika ajali.

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>> Hivyo ni jinsi sisi ni kwenda kutatua tatizo hili?

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