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("%s\n",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 items\n",numwritten); fclose(stream); } else printf("problem opening the file\n"); if ((stream=fopen("fread.out","r+t"))!=null) { numread=fread(list,sizeof(char),25,stream); printf("number of items read =%d\n",numread); printf("contents of buffer=%.25s\n",list); fclose(stream); } else { printf("file could not be opened\n"); } system("pause"); return 0;}
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以上就是c语言“fread”函数的用法？的详细内容。