C语言“fread”函数的用法？
C語言“fread”函數(shù)的用法為“size_tf read(void *buffer,size_t size,size_t count,FILE *stream)”，其作用是從一個文件流中讀數(shù)據(jù)，讀取count個元素，每個元素size字節(jié)。
示例1
#include?
#include?
#include?
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;
}
聲明：
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