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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);
 
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·µ»ØÖµ  ·µ»ØÊµ¼Ê¶ÁÈ¡µ½µÄcountÊýÄ¿¡£
fread·µ»ØµÄ²»ÊÇ×Ö½ÚÊý£¬
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char buff[size];
FILE *fp;
...
realRead = fread(buff, 1, size, fp);
...
Èç¹ûÊÇ: fread(buff, size, 1, fp)
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