linux c copy

#include <stdio.h>
#include <stdlib.h>

int main(int argc, char *argv[]) {
    FILE *source, *destination;
    char ch;

    // 检查命令行参数
    if(argc != 3) {
        fprintf(stderr, "Usage: %s <source file> <destination file>
", argv[0]);
        exit(1);
    }

    // 打开源文件和目标文件
    source = fopen(argv[1], "r");
    if(source == NULL) {
        perror("Error opening source file");
        exit(1);
    }

    destination = fopen(argv[2], "w");
    if(destination == NULL) {
        perror("Error opening destination file");
        fclose(source); // 确保源文件被关闭
        exit(1);
    }

    // 复制文件内容
    while((ch = fgetc(source)) != EOF) {
        fputc(ch, destination);
    }

    // 关闭文件
    fclose(source);
    fclose(destination);

    printf("File copied successfully.
");
    return 0;
}

#include <fcntl.h>
#include <unistd.h>
#include <stdlib.h>

#define BUFFER_SIZE 4096

int main(int argc, char *argv[]) {
    int source_fd, destination_fd;
    char buffer[BUFFER_SIZE];
    ssize_t bytes_read, bytes_written;

    if(argc != 3) {
        fprintf(stderr, "Usage: %s <source file> <destination file>
", argv[0]);
        exit(1);
    }

    source_fd = open(argv[1], O_RDONLY);
    if(source_fd == -1) {
        perror("Error opening source file");
        exit(1);
    }

    destination_fd = open(argv[2], O_WRONLY | O_CREAT | O_TRUNC, 0644);
    if(destination_fd == -1) {
        perror("Error opening destination file");
        close(source_fd);
        exit(1);
    }

    while((bytes_read = read(source_fd, buffer, BUFFER_SIZE)) > 0) {
        bytes_written = write(destination_fd, buffer, bytes_read);
        if(bytes_written != bytes_read) {
            perror("Error writing to destination file");
            close(source_fd);
            close(destination_fd);
            exit(1);
        }
    }

    if(bytes_read == -1) {
        perror("Error reading from source file");
    }

    close(source_fd);
    close(destination_fd);

    printf("File copied successfully.
");
    return 0;
}