Oh Shucks, I Forgot That

Little things that cost you big time, big time.

1. I got the following error message when I used the  "make" command
   Makefile:9: *** missing separator.  Stop.

   You did not use a <tab>-character before the command; you used
   spaces instead.

2.  By mistake I created a file with the name -Wall.  How do I get rid
    of it?

         rm -- -Wall

    The -- option for rm tells rm to not consider any subsequent "-"
    as an option.

3.  I get a segmantation fault or a bus error.

     You have (mistakenly) accessed the (non-existent) contents of
     a NULL or uninitialized pointer.

4.  I get an "undefined symbol" message.  You have declared a function
    but not defined it (even though you think you have).  Using g++
    on the following file
      #include <fstream.h>
      int x(char a);

      int main()  {cout<<x(2)<<endl;}

      int x(int n){return n+1;}
    produced the following (linking) error
        /var/tmp/cc07mGKr.o: In function `main':
        /var/tmp/cc07mGKr.o(.text+0x8): undefined reference to `x(char)'
        collect2: ld returned 1 exit status
    because there is no definition corresponding to the prototype.

5.  Using a template class I get scads of undefined symbols. Perhaps
    you have a .h file and .cc, and you are compiling the .cc file.  You
    should not. Everything should go in the .h file and be compiled by
    the program or class that uses it.