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ÕæÊµ¶ÁÈë×Ö½ÚÊý¾ÍΪrealRead*sizeof(item)  
 RETURN VALUE
       fread  and  fwrite  return the number of items successfully read or written (i.e., not the number of
       characters).  If an error occurs, or the end-of-file is reached, the return value is  a  short  item
       count (or zero).
       fread does not distinguish between end-of-file and error, and callers must use feof(3) and ferror(3)
       to determine which occurred.
fread£¨´ÓÎļþÁ÷¶ÁÈ¡Êý¾Ý£©  
 
±íÍ·Îļþ  #include<stdio.h>
 
¶¨Ò庯Êý  size_t fread(void * ptr,size_t size,size_t count,FILE * stream);
 
º¯Êý˵Ã÷  fread()ÓÃÀ´´ÓÎļþÁ÷ÖжÁÈ¡Êý¾Ý¡£²ÎÊýstreamΪÒÑ´ò¿ªµÄÎļþÖ¸Õ룬²ÎÊýptr Ö¸ÏòÓû´æ·Å¶ÁÈ¡½øÀ´µÄÊý¾Ý¿Õ¼ä£¬¶ÁÈ¡µÄ×Ö½ÚÊýÒÔ²ÎÊýsize*countÀ´¾ö¶¨¡£
Fread()»á·µ»ØÊµ¼Ê¶ÁÈ¡µ½µÄcountÊýÄ¿£¬Èç¹û´ËÖµ±È²ÎÊýcountÀ´µÃС£¬Ôò´ú±í¿ÉÄܶÁµ½ÁËÎļþβÁË»òÕßÓдíÎó·¢Éú(ǰÕß¼¸ÂÊ´ó)£¬Õâʱ±ØÐëÓÃfeof()»òferror()À´¾ö¶¨·¢ÉúʲôÇé¿ö¡£
 
·µ»ØÖµ  ·µ»ØÊµ¼Ê¶ÁÈ¡µ½µÄcountÊýÄ¿¡£
fread·µ»ØµÄ²»ÊÇ×Ö½ÚÊý£¬
µ±ÇÒ½öµ±ÏÂÃæÕâôÓõÄʱºò£¬·µ»ØÖµ²ÅÊÇ×Ö½ÚÊý£¨µ±È»ÒòΪǡºÃÒ»¸öÊý¾Ý¿é´óСΪ1¸ö×Ö½Ú£¬Ï൱ÓÚrealRead*1£©
char buff[size];
FILE *fp;
...
realRead = fread(buff, 1, size, fp);
...
Èç¹ûÊÇ: fread(buff, size, 1, fp)
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