linux实现CP指令
实现CP指令只需要五步
1.打开Src文件（源文件）
2.读Src到Buf
3.打开Des文件（目标文件）
4.写Buf到Des
5.关闭Src和Des文件
代码如下：
#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;
}