How can I suppress the header for the first page in a chapter

Question

I'm trying to implement a macro that begins a chapter. I don't want to use latex or fancyhdr but only plain tex (for pedagogical reasons). The code is the following

\headline={\hfil{\tenrm\folio}\hfil}
\nopagenumbers
% Counters and macros for handling chapters
\newcount\fChapterNumber
\global\fChapterNumber=0
\def\fBeginChapter#1{
  % Initialization
  \advance\fChapterNumber by 1
  % Formatting
  \vfill\eject
  \hrule height0.7mm
  \vskip 5mm
  \centerline{\tenrm \noindent Chapter \the\fChapterNumber}
  \vskip 18mm
  {\tenbf \noindent #1}
  \vskip 35mm
}

% DOCUMENT %
\fBeginChapter{Analisis I}
blah, blah, blah, blah,...
\vfill\eject
blah, blah, blah, blah,...
\bye

As you can see the header will be printed in both pages, but I want it not to be printed in the first page of the chapter. I've been thinking and looking in the web unsuccessfully. What is the best way to do this?

Answer 1

Use a conditional:

% Counters and macros for handling chapters
\newif\iffChapter
\newcount\fChapterNumber
\fChapterNumber=0
\def\fBeginChapter#1{
  % Initialization
  \global\advance\fChapterNumber by 1
  % Formatting
  \vfill\eject
  \global\fChaptertrue
  \hrule height0.7mm
  \vskip 5mm
  \centerline{\tenrm \noindent Chapter \the\fChapterNumber}
  \vskip 18mm
  {\tenbf \noindent #1}
  \vskip 35mm
}

\headline={\iffChapter\global\fChapterfalse\else\hfil{\tenrm\folio}\hfil\fi}
\nopagenumbers


% DOCUMENT %
\fBeginChapter{Analisis I}
blah, blah, blah, blah,...
\vfill\eject
blah, blah, blah, blah,...
\bye

The begin chapter command sets the conditional to true; when this is the case, the code in the header just switches the conditional to false, otherwise it prints the page number.

Notice that your \global\fChapterNumber=0 is useless, while a \global should be in front of \advance\fChapterNumber.

If you want to set the page number at the bottom in the chapter starting pages, you can use the same idea:

\headline={\iffChapter\else\hfil{\tenrm\folio}\hfil\fi}
\footline={\iffChapter\hfil{\tenrm\folio}\hfil\global\fChapterfalse\fi}

and no \nopagenumbers; setting \iffChapter to false must be done by the footline code, as it is executed after the one in the headline.

Answer 2

A simplistic way is to check for odd numbers.

\headline={\hfil{\tenrm\folio}\hfil}
\nopagenumbers
% Counters and macros for handling chapters
\newcount\fChapterNumber
\global\fChapterNumber=0
\def\fBeginChapter#1{
  % Initialization
  \advance\fChapterNumber by 1
  % Formatting
  \ifodd\the\fChapterNumber\vfill\eject
  \hrule height0.7mm
  \vskip 5mm
  \centerline{\tenrm \noindent Chapter \the\fChapterNumber}
  \vskip 18mm
  {\tenbf \noindent #1}
  \vskip 35mm
 \fi
}

% DOCUMENT %
\fBeginChapter{Analisis I}
blah, blah, blah, blah,...
\vfill\eject
blah, blah, blah, blah,...
\bye

However, to be correct you need to call your routines through the output routine.