The problem with fprintf

[jessie9a]

I write some codes below
FILE * fp;
int j=0;
char FileName[100]={0};

sprintf(FileName,"C:\\mttemp.txt");

if((fp=fopen(FileName,"a+"))!=NULL)
{

j=fprintf(fp,"hello\n");
fclose(fp);
}

After execute it , var j is 6,and the new file C:\mttemp.txt was created,but there is nothing in the file C:\mttemp.txt.
What's wrong?

[Peter Sparlinek]

Hi.

Your code works fine on my system. When do you view the file? You have to wait until the call to fclose( fp ) is finished. Since you used buffered I/O the text is first written to some buffer and not directly to the file. Check the contents of your file AFTER fclose(fp).

Peter

[marsh_pottaye]

...or call fflush after fprintf.

[jessie9a]

Thanks very much, Peter and marsh. i have resolved the problem.