用linux编写cp程序

cp [选项] 源 目标

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <errno.h>

void copy_file(const char *src, const char *dest) {
    int src_fd, dest_fd;
    char buffer[4096];
    ssize_t bytes_read, bytes_written;

    // 打开源文件
    src_fd = open(src, O_RDONLY);
    if (src_fd == -1) {
        perror("open");
        exit(EXIT_FAILURE);
    }

    // 创建目标文件
    dest_fd = open(dest, O_WRONLY | O_CREAT | O_TRUNC, S_IRUSR | S_IWUSR);
    if (dest_fd == -1) {
        perror("open");
        close(src_fd);
        exit(EXIT_FAILURE);
    }

    // 复制文件内容
    while ((bytes_read = read(src_fd, buffer, sizeof(buffer))) > 0) {
        bytes_written = write(dest_fd, buffer, bytes_read);
        if (bytes_written != bytes_read) {
            perror("write");
            close(src_fd);
            close(dest_fd);
            exit(EXIT_FAILURE);
        }
    }

    // 关闭文件描述符
    close(src_fd);
    close(dest_fd);
}

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

    copy_file(argv[1], argv[2]);

    return 0;
}

gcc -o cp cp.c

./cp source_file destination_file