fread是一个函数。从一个文件流中读数据，最多读取count个元素，每个元素size字节，如果调用成功返回实际读取到的元素个数，如果不成功返回 0。
#include<stdio.h>#include<string.h>intmain(void){ FILE*
stream; charmsg[]="thisisatest"; charbuf[20]; if((stream=fopen("DUMMY.FIL","w+"))==NULL){ fprintf(stderr,"Cannotopenoutputfile.\n"); return0;}fwrite(msg,1,strlen(msg)+1,stream);fseek(stream,0,SEEK_SET);fread(buf,1,strlen(msg)+1,stream);printf("%s\n",buf);fclose(stream);return0;}#include<stdio.h>intmain(void){ FILE*
stream; charlist[30]; inti,numread,numwritten;/*Openfileintextmode:*/ if((stream=fopen("fread.out","w+t"))!=NULL) {for(i=0;i<25;i++)list[i]=(char)(‘z‘-i); /*Write25characterstostream*/numwritten=fwrite(list,sizeof(char),25,stream);printf("Wrote%ditems\n",numwritten);fclose(stream);}else printf("Problemopeningthefile\n");if((stream=fopen("fread.out","r+t"))!=NULL){
numread=fread(list,sizeof(char),25,stream);printf("Numberofitemsread=%d\n",numread);printf("Contentsofbuffer=%.25s\n",list);fclose(stream);}elseprintf("Filecouldnotbeopened\n");}原文：http://www.cnblogs.com/alsofly/p/3725248.html