/****************************************************
Function:copy an exist file to another file
Author:DarkPower
Date:2010.12.27
****************************************************/
#include<stdio.h>
#include<unistd.h>
#include<fcntl.h>
#include<sys/types.h>
#include<sys/stat.h>
#include<errno.h>
#include<stdlib.h>
#define BUFFSIZE 1024
int main(int argc,char* argv[])
{
int fd1,fd2;
char buff[BUFFSIZE];
char *str;
int nread,nwrite;
if(argc!=3)
{
printf("error command line\n");
exit(1);
}
if((fd1=open(argv[1],O_RDWR))==-1)//open exist file argv[1]
{
printf("open file %s error\n",argv[1]);
exit(1);
}
if((fd2=open(argv[2],O_RDWR|O_CREAT,0755))==-1)//creat file argv[2]
{
printf("creat %s failed\n",argv[2]);
exit(1);
}
while(nread=read(fd1,buff,BUFFSIZE))//read from argv[1]
{
if((nread==-1)&&(errno!=EINTR))break;
else if(nread>0)
{
str=buff;
while(nwrite=write(fd2,str,nread))//write to argv[2]
{
if((nwrite==-1)&&(errno!=EINTR))break;
else if(nwrite==nread)break;
else if(nwrite>0)
{
str=str+nwrite;
nread=nread-nwrite;
}
}
if(nwrite==-1)break;
}
}
close(fd1);
close(fd2);
exit(0);
}
