[Flex-help] Possibly outdated examples from manual

[André W. V. <awv...@gm...>]

Hello,

I'm new to flex. I tried running examples from this page
http://flex.sourceforge.net/manual/Simple-Examples.html#Simple-Examples on
flex 2.6.0 (which came installed on Linux Mint 18).

This example

                 int num_lines = 0, num_chars = 0;

         %%
         \n      ++num_lines; ++num_chars;
         .       ++num_chars;

         %%

         int main()
                 {
                 yylex();
                 printf( "# of lines = %d, # of chars = %d\n",
                         num_lines, num_chars );
                 }

first produced a premature end-of-file as a result. After removing leading
tabs, it produced a C source file with the following errors when compiled
using gcc:

<stdin>: In function ‘yylex’:
<stdin>:4:3: error: ‘num_lines’ undeclared (first use in this function)
<stdin>:4:3: note: each undeclared identifier is reported only once for
each function it appears in
<stdin>:4:16: error: ‘num_chars’ undeclared (first use in this function)
<stdin>: In function ‘main’:
<stdin>:14:9: error: ‘num_lines’ undeclared (first use in this function)
<stdin>:14:20: error: ‘num_chars’ undeclared (first use in this function)


I searched for a solution and found out that the first section of the file
should be put between %{
and %}.

The manual might need to be updated to conform with current versions of
flex. Is that the case?

Cheers,
André