10-dars: File I/O (Fayl bilan ishlash)

Dars haqida

Davomiyligi: 90 daqiqa Maqsad: Talaba fayl ochish, yozish, o'qish va yopishni o'rganishi kerak.

1. Nima uchun fayl?

Dastur tugagandan keyin — xotirada saqlangan ma'lumot yo'qoladi.

Fayl — ma'lumotni diskda saqlash.

2. FILE pointer

#include <stdio.h>

FILE *fp;  // fayl pointeri

FILE — standart struct, fayl haqida ma'lumot saqlaydi.

3. fopen — fayl ochish

FILE *fp = fopen("data.txt", "r");

Rejimlar:

Mode	Vazifa
`"r"`	Read (o'qish)
`"w"`	Write (yozish, mavjud bo'lsa o'chiriladi)
`"a"`	Append (qo'shish)
`"r+"`	Read + Write
`"w+"`	Write + Read (ustiga yozish)
`"a+"`	Append + Read
`"rb"`	Binary read
`"wb"`	Binary write

4. NULL tekshirish

FILE *fp = fopen("data.txt", "r");
if (fp == NULL) {
    printf("Faylni ochib bo'lmadi!\n");
    return 1;
}

Doim tekshiring — fayl yo'q, ruxsat yo'q yoki boshqa muammo bo'lishi mumkin.

5. fclose — fayl yopish

fclose(fp);

Doim yoping — ma'lumot diskka yoziladi va resurs bo'shatiladi.

6. fprintf — faylga yozish

printf'ga o'xshash, lekin faylga:

FILE *fp = fopen("output.txt", "w");
if (!fp) return 1;

fprintf(fp, "Salom dunyo!\n");
fprintf(fp, "Yoshim: %d\n", 22);
fprintf(fp, "Pi: %.5f\n", 3.14159);

fclose(fp);

Fayl ichida:

Salom dunyo!
Yoshim: 22
Pi: 3.14159

7. fscanf — fayldan o'qish

scanf'ga o'xshash:

FILE *fp = fopen("data.txt", "r");
if (!fp) return 1;

int n;
double d;
char s[100];

fscanf(fp, "%d %lf %s", &n, &d, s);
printf("%d %f %s\n", n, d, s);

fclose(fp);

8. fgetc va fputc — bitta belgi

FILE *fp = fopen("data.txt", "r");
int c;

while ((c = fgetc(fp)) != EOF) {
    putchar(c);
}

fclose(fp);

fgetc — bitta belgi. EOF — End Of File.

9. fgets va fputs — qator

FILE *fp = fopen("data.txt", "r");
char line[256];

while (fgets(line, sizeof(line), fp) != NULL) {
    printf("%s", line);  // line'da \n bor
}

fclose(fp);

FILE *fp = fopen("output.txt", "w");
fputs("Birinchi qator\n", fp);
fputs("Ikkinchi qator\n", fp);
fclose(fp);

10. Misol: Yozish va o'qish

Yozish:

#include <stdio.h>

int main(void) {
    FILE *fp = fopen("students.txt", "w");
    if (!fp) return 1;
    
    fprintf(fp, "Akmal 22 95.5\n");
    fprintf(fp, "Aziza 19 92.0\n");
    fprintf(fp, "Botir 25 78.5\n");
    
    fclose(fp);
    printf("Yozildi!\n");
    return 0;
}

O'qish:

#include <stdio.h>

int main(void) {
    FILE *fp = fopen("students.txt", "r");
    if (!fp) return 1;
    
    char name[50];
    int age;
    double score;
    
    while (fscanf(fp, "%s %d %lf", name, &age, &score) == 3) {
        printf("%s, %d yosh, %.1f ball\n", name, age, score);
    }
    
    fclose(fp);
    return 0;
}

11. Append rejim

FILE *fp = fopen("log.txt", "a");
fprintf(fp, "Yangi log: %s\n", "ish boshlandi");
fclose(fp);

Mavjud fayl o'chirilmaydi — yangi ma'lumot oxiriga qo'shiladi.

12. Binary file

Matn emas, bayt-bayt yozish/o'qish.

#include <stdio.h>

typedef struct {
    char name[50];
    int age;
    double score;
} Student;

int main(void) {
    Student students[3] = {
        {"Akmal", 22, 95.5},
        {"Aziza", 19, 92.0},
        {"Botir", 25, 78.5}
    };
    
    // Yozish (binary)
    FILE *fp = fopen("students.bin", "wb");
    fwrite(students, sizeof(Student), 3, fp);
    fclose(fp);
    
    // O'qish (binary)
    Student loaded[3];
    fp = fopen("students.bin", "rb");
    fread(loaded, sizeof(Student), 3, fp);
    fclose(fp);
    
    for (int i = 0; i < 3; i++) {
        printf("%s %d %.1f\n", loaded[i].name, loaded[i].age, loaded[i].score);
    }
    
    return 0;
}

13. fread va fwrite

size_t fread(void *ptr, size_t size, size_t count, FILE *stream);
size_t fwrite(const void *ptr, size_t size, size_t count, FILE *stream);

ptr — qaysi joydan/joyga
size — bir elementning hajmi
count — necha element
Return: muvaffaqiyatli o'qilgan/yozilgan element soni

14. fseek va ftell

Fayl ichida harakat:

fseek(fp, 100, SEEK_SET);  // boshidan 100 byte
fseek(fp, -10, SEEK_END);  // oxirdan -10 byte
fseek(fp, 50, SEEK_CUR);   // hozirgi joydan +50

long position = ftell(fp);  // hozirgi joy

Konstanta	Ma'no
`SEEK_SET`	Boshidan
`SEEK_CUR`	Hozirgi joydan
`SEEK_END`	Oxirdan

15. Fayl hajmini topish

fseek(fp, 0, SEEK_END);
long size = ftell(fp);
fseek(fp, 0, SEEK_SET);  // boshiga qaytish

printf("Fayl hajmi: %ld byte\n", size);

16. Misol: Word count

#include <stdio.h>
#include <ctype.h>

int main(void) {
    FILE *fp = fopen("document.txt", "r");
    if (!fp) return 1;
    
    int chars = 0, words = 0, lines = 0;
    int in_word = 0;
    int c;
    
    while ((c = fgetc(fp)) != EOF) {
        chars++;
        
        if (c == '\n') lines++;
        
        if (isspace(c)) {
            in_word = 0;
        } else if (!in_word) {
            in_word = 1;
            words++;
        }
    }
    
    fclose(fp);
    
    printf("Belgilar: %d\n", chars);
    printf("So'zlar: %d\n", words);
    printf("Qatorlar: %d\n", lines);
    
    return 0;
}

Unix'dagi wc buyrug'iga o'xshash.

17. Misol: Cat dasturi

#include <stdio.h>

int main(int argc, char *argv[]) {
    if (argc != 2) {
        printf("Foydalanish: %s <fayl>\n", argv[0]);
        return 1;
    }
    
    FILE *fp = fopen(argv[1], "r");
    if (!fp) {
        printf("Faylni ochib bo'lmadi: %s\n", argv[1]);
        return 1;
    }
    
    int c;
    while ((c = fgetc(fp)) != EOF) {
        putchar(c);
    }
    
    fclose(fp);
    return 0;
}

Kompilyatsiya: gcc cat.c -o mycat Ishlatish: ./mycat hello.txt

18. Misol: Faylni nusxalash

#include <stdio.h>

int main(int argc, char *argv[]) {
    if (argc != 3) {
        printf("Foydalanish: %s <src> <dst>\n", argv[0]);
        return 1;
    }
    
    FILE *src = fopen(argv[1], "rb");
    FILE *dst = fopen(argv[2], "wb");
    
    if (!src || !dst) return 1;
    
    char buffer[1024];
    size_t n;
    while ((n = fread(buffer, 1, sizeof(buffer), src)) > 0) {
        fwrite(buffer, 1, n, dst);
    }
    
    fclose(src);
    fclose(dst);
    
    printf("Nusxalandi: %s -> %s\n", argv[1], argv[2]);
    return 0;
}

19. Common pitfalls

1. NULL tekshirmaslik

FILE *fp = fopen("yoq.txt", "r");
fprintf(fp, "...");  // CRASH (fp = NULL)

2. fclose unutish

FILE *fp = fopen("data.txt", "w");
fprintf(fp, "...");
// fclose yo'q — ma'lumot diskka yozilmasligi mumkin

3. Buffer kichik

char line[10];
fgets(line, sizeof(line), fp);
// uzun qator kesiladi

4. Mode noto'g'ri

fopen("file.txt", "w");
fread(...);  // XATO — write mode

fopen("file.txt", "r");
fwrite(...);  // XATO

20. Standart fayllar

3 ta avtomatik fayl:

stdin — klaviatura
stdout — ekran
stderr — xato chiqarish

fprintf(stderr, "Xato: %s\n", message);  // ekranga (xato uchun)
fprintf(stdout, "OK\n");                  // ekranga
fscanf(stdin, "%d", &n);                  // klaviaturadan

scanf aslida fscanf(stdin, ...) ga teng.

Darsdagi topshiriqlar

1 — Birinchi fayl

first.c:

#include <stdio.h>

int main(void) {
    FILE *fp = fopen("hello.txt", "w");
    if (!fp) return 1;
    
    fprintf(fp, "Salom dunyo!\n");
    fprintf(fp, "Bu mening birinchi faylim.\n");
    
    fclose(fp);
    printf("Yozildi!\n");
    return 0;
}

cat hello.txt qiling — nima ko'rinadi?

2 — O'qish

read-file.c:

#include <stdio.h>

int main(void) {
    FILE *fp = fopen("hello.txt", "r");
    if (!fp) return 1;
    
    char line[256];
    while (fgets(line, sizeof(line), fp) != NULL) {
        printf("%s", line);
    }
    
    fclose(fp);
    return 0;
}

3 — Talabalar fayli

students-io.c:

5 ta talaba ma'lumotini students.txt'ga yoz
Faylni o'qib chiqar
O'rtacha ballni hisoblash

4 — Append log

log.c:

#include <stdio.h>
#include <time.h>

int main(void) {
    FILE *fp = fopen("app.log", "a");
    if (!fp) return 1;
    
    time_t now = time(NULL);
    fprintf(fp, "[%ld] Dastur ishga tushdi\n", now);
    
    fclose(fp);
    return 0;
}

Dasturni 5 marta ishga tushirib, log faylni ko'ring.

5 — Word count

wc.c — Dars matnidagi to'liq dastur.

Sinab ko'ring: turli .txt fayllar bilan.

6 — Cat

mycat.c — fayl tarkibini ekranga.

Argument bilan:

bash

./mycat hello.txt

7 — Copy

mycopy.c — fayl nusxalash.

bash

./mycopy src.txt dst.txt

8 — Binary struct

binary.c:

Talabalar struct massivini binary faylga yozing va o'qing.

Hajmni taqqoslang: matnli vs binary versiya.

9 — Phone book

phonebook.c:

typedef struct {
    char name[50];
    char phone[20];
} Contact;

Faylga yozish
Faylga qo'shish (append)
Faylni o'qib chiqarish
Ism bo'yicha qidirish

10 — GitHub

bash

$ mkdir 5-oy-dars-10
$ git add . && git commit -m "feat: dars 10 - file I/O" && git push

Lug'at

Termin	Izoh
FILE	Fayl pointeri
fopen	Fayl ochish
fclose	Fayl yopish
fprintf	Faylga yozish (formatlangan)
fscanf	Fayldan o'qish (formatlangan)
fgets / fputs	Qator
fgetc / fputc	Belgi
fread / fwrite	Binary o'qish/yozish
fseek / ftell	Fayl ichida harakat
EOF	End Of File
stdin / stdout / stderr	Standart fayllar
Binary file	Bayt-bayt fayl
Text file	Matn fayl

Keyingi dars

11-dars: Mini loyiha →

10-dars: File I/O (Fayl bilan ishlash) ​

1. Nima uchun fayl? ​

2. FILE pointer ​

3. fopen — fayl ochish ​

4. NULL tekshirish ​

5. fclose — fayl yopish ​

6. fprintf — faylga yozish ​

7. fscanf — fayldan o'qish ​

8. fgetc va fputc — bitta belgi ​

9. fgets va fputs — qator ​

10. Misol: Yozish va o'qish ​

Yozish: ​

O'qish: ​

11. Append rejim ​

12. Binary file ​

13. fread va fwrite ​

14. fseek va ftell ​

15. Fayl hajmini topish ​

16. Misol: Word count ​

17. Misol: Cat dasturi ​

18. Misol: Faylni nusxalash ​

19. Common pitfalls ​

1. NULL tekshirmaslik ​

2. fclose unutish ​

3. Buffer kichik ​

4. Mode noto'g'ri ​

20. Standart fayllar ​

Darsdagi topshiriqlar ​

Lug'at ​

Keyingi dars ​

10-dars: File I/O (Fayl bilan ishlash)

1. Nima uchun fayl?

2. FILE pointer

3. fopen — fayl ochish

4. NULL tekshirish

5. fclose — fayl yopish

6. fprintf — faylga yozish

7. fscanf — fayldan o'qish

8. fgetc va fputc — bitta belgi

9. fgets va fputs — qator

10. Misol: Yozish va o'qish

Yozish:

O'qish:

11. Append rejim

12. Binary file

13. fread va fwrite

14. fseek va ftell

15. Fayl hajmini topish

16. Misol: Word count

17. Misol: Cat dasturi

18. Misol: Faylni nusxalash

19. Common pitfalls

1. NULL tekshirmaslik

2. fclose unutish

3. Buffer kichik

4. Mode noto'g'ri

20. Standart fayllar

Darsdagi topshiriqlar

Lug'at

Keyingi dars