在Linux环境用C语言编写文件复制程序。分别使用系统调用read (fd,buf,nbytes)、write(fd, buf,nbytes)和文件的库函数fread(buf,size,nitems,fp)、fwrite(buf,size,nitems,fp)，编写一个文件复制程序

下面是使用系统调用read和write函数实现的文件复制程序：

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

#define BUFFER_SIZE 1024

int main(int argc, char *argv[]) {
    if (argc != 3) {
        fprintf(stderr, "Usage: %s source_file dest_file\n", argv[0]);
        exit(EXIT_FAILURE);
    }

    int source_fd = open(argv[1], O_RDONLY);

    if (source_fd == -1) {
        perror("open");
        exit(EXIT_FAILURE);
    }

    int dest_fd = open(argv[2], O_WRONLY | O_CREAT | O_TRUNC, 0644);

    if (dest_fd == -1) {
        perror("open");
        exit(EXIT_FAILURE);
    }

    char buffer[BUFFER_SIZE];
    ssize_t read_count, write_count;

    while ((read_count = read(source_fd, buffer, BUFFER_SIZE)) > 0) {
        write_count = write(dest_fd, buffer, read_count);

        if (write_count == -1) {
            perror("write");
            exit(EXIT_FAILURE);
        }
    }

    if (read_count == -1) {
        perror("read");
        exit(EXIT_FAILURE);
    }

    if (close(source_fd) == -1) {
        perror("close");
        exit(EXIT_FAILURE);
    }

    if (close(dest_fd) == -1) {
        perror("close");
        exit(EXIT_FAILURE);
    }

    return 0;
}

下面是使用文件的库函数fread和fwrite函数实现的文件复制程序：

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

#define BUFFER_SIZE 1024

int main(int argc, char *argv[]) {
    if (argc != 3) {
        fprintf(stderr, "Usage: %s source_file dest_file\n", argv[0]);
        exit(EXIT_FAILURE);
    }

    FILE *source_fp = fopen(argv[1], "rb");

    if (source_fp == NULL) {
        perror("fopen");
        exit(EXIT_FAILURE);
    }

    FILE *dest_fp = fopen(argv[2], "wb");

    if (dest_fp == NULL) {
        perror("fopen");
        exit(EXIT_FAILURE);
    }

    char buffer[BUFFER_SIZE];
    size_t read_count, write_count;

    while ((read_count = fread(buffer, 1, BUFFER_SIZE, source_fp)) > 0) {
        write_count = fwrite(buffer, 1, read_count, dest_fp);

        if (write_count != read_count) {
            perror("fwrite");
            exit(EXIT_FAILURE);
        }
    }

    if (ferror(source_fp)) {
        perror("fread");
        exit(EXIT_FAILURE);
    }

    if (fclose(source_fp) != 0) {
        perror("fclose");
        exit(EXIT_FAILURE);
    }

    if (fclose(dest_fp) != 0) {
        perror("fclose");
        exit(EXIT_FAILURE);
    }

    return 0;
}