b.c

这个是在linux下面的用c语言读写虚拟软盘的源程序

#include<stdio.h>
struct f
{
	char filename[8];
	char fileex[3];
	char shuxing;
	char baoliu[10];
	char shijian[2];
	char riqi[2];
	char qishi[2];
	char daxiao[4];
}file[244];
int fd_rename(char *oldfilename,char *newfilename)
{
	int f,i,j,k,l,ll;
	char name[11];
	if((f=open("/dev/fd0",2))!=-1)
	{
        lseek(f,512*19,SEEK_SET);
		read(f,file,7168);
		i=0;
		j=0;
                k=0;
		while(1)
		{
			if(file[i].filename[0]!=0xF5&&
                           file[i].filename[0]!=0x00&&
                           file[i].shuxing!=0x08)
			{
				l=0;
                                while(file[i].filename[l]!=0x20&&l<8)
                                {
                                 name[l]=file[i].filename[l];
                                 l++;
                                }
                                ll=0;       
                                while(file[i].fileex[ll]!=0x20&&ll<3)
                                {
                                 if(ll==0){l++;name[ll+l-1]='.';}
                                 name[ll+l]=file[i].fileex[ll];
                                 ll++;
                                }
              			name[l+ll]='\0';
		        	while(name[j]!=0x20&&oldfilename[j]!='\0')
				{
                                 if(oldfilename[j]=='\0')break;
                                 if(name[j]!=oldfilename[j])break;
			       	 j++;
				}
				if(name[j]=='\0'&&
                                   oldfilename[j]=='\0')
				{
				 while(newfilename[k]!='\0')
				 {
				  name[k]=newfilename[k];
				  k++;
				 }
				 break;
				}
			}
			j=0;
			k=0;
			i++;
                        if(i==244)break;
                        
		}
    if(i==244)return -1;
    else 
    {
     j=0;
     l=0;
     k=0;
     while(newfilename[j]!='.'&&newfilename[j]!='\0')
     {
      file[i].filename[j]=newfilename[j];
      j++;
     }   
     l=j;
     while(l<8){file[i].filename[l]=0x20;l++;}
     j++;    
     while(newfilename[j+k]!='\0')
     {if(k==0&&newfilename[j+k-1]!='.')break;
      file[i].fileex[k]=newfilename[j+k];     
      k++;
     }
     while(k<3){file[i].fileex[k]=0x20;k++;}
     lseek(f,19*512,SEEK_SET);
     if(write(f,file,7168)==-1)printf("error write\n");
     return 0;
     }
    }
    else printf("error to open derive!\n");
    return 0;
}
void main()
{
 char *p1,*p2;
 char a[10],b[10];
 int f;
 p1=a;
 p2=b;
 scanf("%s",a);
 scanf("%s",b);
 f=fd_rename(p1,p2);
 if(f!=0)printf("Can't find the file!\n");
}