open trick

[Anders Torger <torger@xxxxxxxxxxxx>]

When studying the gpm code, I notice that the mouse fd is opened first 
with O_NDELAY, and then directly after it is reset using fcntl, like 
this: 

      if(!strcmp(opt_dev,"-")) fd=0; /* use stdin */
      else if( (fd=open(opt_dev,O_RDWR | O_NDELAY)) < 0)
         gpm_report(GPM_PR_OOPS,GPM_MESS_OPEN,opt_dev); 
             
      /* and then reset the flag */
      fcntl(fd,F_SETFL,fcntl(fd,F_GETFL) & ~O_NDELAY);


I really curious about why this is done.

/Anders Torger