fd.c

用于汇编领域的,运用于OS的MAIN函数.基于硬件基础的源代码

#include "fs.h"

void FDTable_init(struct FilePtr *fd[]){
   int i;
   for(i=0;i<MAX_FD;i++)
      fd[i]=0;
   fd[0]=fd[1]=fd[2]=(struct FilePtr *)-1; 
                         // reserve them. we should open fd 0,1,2 for
                         // /dev/tty, but do it later.
}

int FDTable_get_empty_entry(struct FilePtr *fd[]){
   int i;
   for(i=0;i<MAX_FD;i++)
      if (fd[i]==0) return i;
   panic("no empty entry in fd table\n");
}

int FDTable_report_new_fd(struct FilePtr *fd[],struct FilePtr *fpt){
   int x = FDTable_get_empty_entry(fd);
   fd[x] = fpt;
   return x;
}