C, Ho Bala Litokomane le ho Ngola

Haeba faele ea binary e sebetsoa, ​​​​sebelisa mokhoa o latelang oa phihlello ho khutlisa e kaholimo:

"rb", "wb", "ab", "rb+", "r+b", "wb+", "w+b", "ab+", "a+b"

faele e koetsoeng

Ho koala faele, ka kopo sebelisa ts'ebetso ea fclose(). Prototype ea ts'ebetso ke e latelang:

int fclose ( FILE * fp );

• Haeba faele e koetsoe ka katleho, mosebetsi oa fclose () o khutlisa zero, 'me haeba phoso e khutlisa EOF. Ts'ebetso ena, ha e le hantle, e tlosa data ho buffer, e koala faele, 'me e lokolla memori eohle e sebelisetsoang faele eo. EOF e hlalosoa ka linako tsohle ho file ea hlooho ea stdio.h

Laeborari e tloaelehileng ea C e fana ka mesebetsi e fapaneng ea ho bala le ho ngola lifaele ka litlhaku kapa joalo ka khoele ea bolelele bo tsitsitseng.

Ngola faeleng

Mona ke mesebetsi e bonolo ea ho ngola litlhaku ho molatsoana:

int fputc ( int c , FILE *fp );

Mosebetsi fputc () o ngola boleng ba sebopeho sa paramethara c ho molapo o hlahisoang oo fp e supang ho ona. Haeba ho ngola ho atlehile, e khutlisetsa sebopeho se ngotsoeng le EOF haeba phoso e etsahala. U ka sebelisa ts'ebetso e latelang ho ngola khoele e qetellang ka null ho molapo:

int fputs ( const char *s , FILE *fp );

Mosebetsi oa fputs () o ngola khoele s ho molatsoana oa tlhahiso moo fp e supang teng. Haeba ho ngola ho atleha, e khutlisa boleng bo seng bobe le EOF haeba phoso e etsahala. U ka sebelisa ts'ebetso ea int fprintf (FILE * fp, const char * format,...) e ngola khoele faeleng. Leka mohlala o latelang:

Tlhokomeliso: Etsa bonnete ba hore u na le tmp directory e fumanehang, 'me haeba e le sieo, u lokela ho e etsa khomphuteng ea hau pele.

/ tmp hangata ke buka ea nakoana ea sistimi ea Linux. Haeba o sebelisa sistimi ea Windows, o hloka ho e fetolela bukeng e teng sebakeng sa lehae, joalo ka: C: \ tmp, D: \ tmp, jj.

mohlala o phelang

# kenyeletsa int main () { FILE *fp = NULL ; fp = fopen ("/tmp/test.txt ", "w+"); fprintf (fp , "Sena ke teko ea fprintf...\n "); fputs ("Sena ke teko ea fputs...\n ", fp ); ho koala (fp); }

Ha khoutu e ka holimo e bokelloa le ho etsoa, ​​​​e theha faele e ncha test.txt inthe / tmp directory. Mme o ngolla mela e mmedi a sebedisa ditshebetso tse pedi tse fapaneng. Ha re bale faele ena nakong e tlang.

Bala faele

E latelang ke mosebetsi o bonolo oa ho bala tlhaku e le 'ngoe ho tsoa faeleng:

int fgetc ( FILE * fp );

Mosebetsi oa fgetc () o bala tlhaku ho tsoa faeleng e kentsoeng eo fp e supang ho eona. Boleng ba ho khutla ke sebopeho se baloang le EOF haeba phoso e etsahala. Mosebetsi o latelang o u lumella ho bala khoele ho tsoa molapong:

char *fgets ( char *buf , int n , FILE *fp );

Mosebetsi fgets () o bala litlhaku tsa n-1 ho tsoa ho molapo o kenang o tsamaisoang ke fp. E kopitsa khoele e baloang ho buffer buf ebe e hlomathisa tlhaku e sa sebetseng qetellong ho felisa khoele.

Haeba ts'ebetso ena e kopana le mohala o robehileng '\ n' kapa EOF ea pheletso ea faele pele o bala tlhaku ea ho qetela, ebe o khutlela ho batho bao ho buuoang ka bona, ho kenyelletsa le khefutso ea mela. U ka boela ua sebelisa int fscanf (FILE * fp, const char * format,...) mosebetsi oa ho bala khoele e tsoang faeleng, empa e khaotsa ho bala ha e kopana le sebaka sa pele le ho robeha ha mela.

mohlala o phelang

# kenyeletsa int main () { FILE *fp = NULL ; char buff [255]; fp = fopen ("/tmp/test.txt ", "r"); fscanf (fp , "%s", buff ); printf ("1: %s \n ", buff ); fgets (buff, 255, (FILE *)fp); printf ("2: %s \n ", buff ); fgets (buff, 255, (FILE *)fp); printf ("3: %s \n ", buff ); ho koala (fp); }

Ha khoutu e ka holimo e hlophisitsoe le ho etsoa, ​​​​e bala lifaele tse entsoeng karolong e fetileng, e hlahisa liphetho tse latelang:

1: Ena ea 2: e etsa tlhahlobo ea fprintf...

3: Sena ke tlhahlobo ea fputs ...

Ntlha ea pele, mokhoa oa fscanf() o bala feela Sena .hobane e kopana le sebaka ka morao. Ea bobeli, letsetsa functon fgets () ho bala karolo e setseng ho fihlela qetellong ea mola. Qetellong, letsetsa fgets () ho bala mola oa bobeli ka ho feletseng.

Binary I / O tshebetso

Mesebetsi e 'meli e latelang e sebelisoa bakeng sa tlhahiso le tlhahiso ea binary:

boholo_t fread (boid *ptr , size_t size_of_elements , size_t number_of_elements , FILE * a_file ); size_t fwrite (consst void *ptr , size_t size_of_elements , size_t number_of_elements , FILE *a_file);

Mesebetsi ka bobeli e baloa le ho ngoloa bakeng sa li-blocks tsa polokelo-hangata li-arrays kapa mehaho.

Ka holimo hoo e ka bang C faele ea ho bala le ho ngola ke ea HDV Phoelectron Technology Ltd., software technical operation. Le k'hamphani ea lisebelisoa tse amanang le marang-rang (joalo ka: ACONU/ puisanoONU/ bohlaleONU/ fiberONU, joalo-joalo) e kopantse sehlopha se matla sa software, bakeng sa moreki e mong le e mong ho etsa litlhoko tse ikhethileng tsa ba e hlokang, hape re lumelle lihlahisoa tsa rona hore li be bohlale le ho feta.