Simple operation of file API in C/C++

The C/C++ file API is a set of functions used for manipulating files, such as creating, opening, reading, writing, and closing. Here are some common examples of simple file operations using the C/C++ file API:

1. Create a file.

#include <stdio.h>

int main() {
    FILE *file;
    file = fopen("example.txt", "w");  // 打开文件，如果不存在则新建
    if (file == NULL) {
        printf("无法创建文件\n");
        return 1;
    }
    fclose(file);  // 关闭文件
    return 0;
}

1. Write to file.

#include <stdio.h>

int main() {
    FILE *file;
    file = fopen("example.txt", "w");
    if (file == NULL) {
        printf("无法打开文件\n");
        return 1;
    }
    fprintf(file, "Hello, World!\n");  // 写入内容
    fclose(file);
    return 0;
}

1. Read the file:

#include <stdio.h>

int main() {
    FILE *file;
    char buffer[255];
    file = fopen("example.txt", "r");
    if (file == NULL) {
        printf("无法打开文件\n");
        return 1;
    }
    fgets(buffer, sizeof(buffer), file);  // 读取一行内容
    printf("读取内容：%s", buffer);
    fclose(file);
    return 0;
}

1. Add additional content to the file.

#include <stdio.h>

int main() {
    FILE *file;
    file = fopen("example.txt", "a");
    if (file == NULL) {
        printf("无法打开文件\n");
        return 1;
    }
    fprintf(file, "This is appended content.\n");  // 追加内容
    fclose(file);
    return 0;
}

These examples only cover the basic usage of some file APIs in the C language, and there are similar file operation functions in C++. In actual development, there are also more file operation functions and error handling mechanisms to consider.