Linux实现cp指令（4.14）

参数：argc是参数总个数

        argv是数组的指针，例如argv[0]是cp，argv[1]是src.c，argv[2]是dec.c。

思路：

1. 打开src.c
2. 读src.c到buf
3. 打开/创建desc.c
4. 将buf写入des.c
5. close两个文件

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

int main(int argc,char **argv)
{
        int fdSrc;
        int fdDes;

        char *readBuf = NULL;

        if(argc != 3){
                printf("pararm error\n");
                exit(-1);
        }

        fdSrc = open(argv[1],O_RDWR);
        int size = lseek(fdSrc,0,SEEK_END);
        lseek(fdSrc,0,SEEK_SET);

        readBuf = (char *)malloc(sizeof(char)*size + 8);

        int n_read = read (fdSrc,readBuf,size);

        fdDes = open(argv[2],O_RDWR|O_CREAT|O_TRUNC,0600);

        int n_write = write(fdDes,readBuf,strlen(readBuf));

        close(fdSrc);
        close(fdDes);

        return 0;
}

结果：