C语言“fread”函数的用法？

C语言“fread”函数的用法？

C语言“fread”函数的用法为“size_tf read(void *buffer,size_t size,size_t count,FILE *stream)”，其作用是从一个文件流中读数据，读取count个元素，每个元素size字节。

示例1

#include <stdio.h>#include <process.h>#include <string.h>int main(){FILE *stream;char msg[]="this is a test";char buf[20];if ((stream=fopen("dummy.fil","w+"))==NULL){fprintf(stderr,"cannot open output file.n");return 1;}/*write some data to the file*/fwrite(msg,1,strlen(msg)+1,stream);/*seek to the beginning of the file*/fseek(stream,0,SEEK_SET);/*read the data and display it*/fread(buf,1,strlen(msg)+1,stream);printf("%sn",buf);fclose(stream);system("pause");return 0;}

示例2

int main(void){FILE *stream;char list[30];int i,numread,numwritten;/*open file in text mode:*/if ((stream=fopen("fread.out","w+t"))!=NULL){for (i=0;i<25;i++){list[i]=(char)('z'-i);}/*write 25 characters to stram*/numwritten=fwrite(list,sizeof(char),25,stream);printf("Wrote %d itemsn",numwritten);fclose(stream);}elseprintf("Problem opening the filen");        if ((stream=fopen("fread.out","r+t"))!=NULL)        {numread=fread(list,sizeof(char),25,stream);printf("Number of items read =%dn",numread);printf("Contents of buffer=%.25sn",list);fclose(stream);        }         else        {printf("File could not be openedn");        }system("pause");return 0;}