文件内容输入

方法1

#include 
int main(){

   FILE * fd= fopen("/home/llc/abc.txt","w");
    fprintf(fd,"hello\n");
    fflush(fd);
    fclose(fd);
 return 0;

}

方法2

#include 
int main(){
   FILE * fd= fopen("/home/llc/abc.txt","w");
 for (int i = 65; i < 65+26; ++i) {
        fputc(i,fd);
 printf("%c\n", i);
    }
fclose(fd);
return 0;
}