c语言文件读写操作代码

以下是 C 语言中文件读写操作的常用代码示例：

1. 文件读取操作

#include <stdio.h>

int main() {
    FILE *fp;
    char buffer[255];

    fp = fopen("example.txt", "r");

    if (fp == NULL) {
        printf("File does not exist!");
        return 0;
    }

    // 从文件中读取一行数据
    fgets(buffer, 255, fp);

    printf("%s", buffer);
    fclose(fp);

    return 0;
}

2. 文件写入操作

#include <stdio.h>

int main() {
    FILE *fp;

    fp = fopen("example.txt", "w");

    if (fp == NULL) {
        printf("File does not exist!");
        return 0;
    }

    // 写入数据到文件中
    fprintf(fp, "This is an example file.\n");
    fputs("This is another line.", fp);

    fclose(fp);

    return 0;
}

3. 二进制文件读取操作

#include <stdio.h>

int main() {
    FILE *fp;
    int n;
    float x;

    fp = fopen("example.bin", "rb");

    if (fp == NULL) {
        printf("File does not exist!");
        return 0;
    }

    // 从二进制文件中读取数据
    fread(&n, sizeof(int), 1, fp);
    fread(&x, sizeof(float), 1, fp);

    printf("n = %d, x = %f", n, x);
    fclose(fp);

    return 0;
}

4. 二进制文件写入操作

#include <stdio.h>

int main() {
    FILE *fp;
    int n = 10;
    float x = 3.14;

    fp = fopen("example.bin", "wb");

    if (fp == NULL) {
        printf("File does not exist!");
        return 0;
    }

    // 将数据写入二进制文件中
    fwrite(&n, sizeof(int), 1, fp);
    fwrite(&x, sizeof(float), 1, fp);

    fclose(fp);

    return 0;
}