cp.c

This is to bulid a sample linux shell.

//copies one file to another 
 

#include<fcntl.h>
#include<sys/stat.h>
#define BUFSIZE 1024 
#include<stdlib.h>
int main(int argc ,char **argv)
{
   int fd1,fd2;
   int n,j;
   char buf[BUFSIZE];
   fd1=open(argv[1],O_RDONLY); 
  for(j=argc;j>1;j--) 
  {fd2=open(argv[j-1],O_WRONLY|O_CREAT|O_TRUNC|S_IRUSR|S_IWUSR|S_IROTH);

   while((n=read(fd1,buf,BUFSIZE))>0)
           write(fd2,buf,n);
    close(fd2);
   }
  close(fd1);
    exit(0);
}