Write a string or a number to a file

file_write.c

void writestring(char *);
void writedigit(int);
void writestring(char *s)
{
	FILE *fp;
	char nl[]="\n";
	fp=fopen("output","a");
	fprintf(fp,"%s",nl);
	fprintf(fp,"%s",s);
	fclose(fp);
}

void writedigit(int s)
{
	FILE *fp;
	char nl[]="\n";
	fp=fopen("output","a");
	fprintf(fp,"%s",nl);
	fprintf(fp,"%d",s);
	fclose(fp);
}

File is created if not existing, if exists then appended