Does fprintf() always write over what's already in a file?

Question

Say I have the following:

FILE *fp1 = fopen("file.txt", "w");
fprintf(fp1,"%i\n",counter);

When I run my program, it writes the counter to the file. But when I run the program again and end up with a different counter, instead of writing that counter below the first one, it just replaces the first one. Is there a way to make it not just replace whats already in the file each time I run the program?

Answer 1

将文件访问模式设置为"a" （附加），如下所示：

FILE *fp1 = fopen("file.txt", "a");