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This question seems to be related to a previous (comp.text.tex #77843,
thanks to David Carlisle for his answer). I want to have the
beginning and the end of a table in two differents files.

If I try the following with foo1.tex and foo2.tex

%%%%%% begin of foo1.tex
\documentclass{article}

\begin{document}

\begin{tabular}{|c|c|c|} \hline
A & B & C \\ \hline \hline
1 & 2 & 3 \\ \hline
%%%%%% end of foo1.tex

%%%%%% begin of foo2.tex
\input{essai_header}
\end{tabular}

\end{document}
%%%%%% end of foo2.tex

The output generated by `latex foo2` is the expected one:

 -------------
 | A | B | C |
 -------------
 | 1 | 2 | 3 |
 -------------

but if I try the following with foo3.tex and foo4.tex

%%%%%% begin of foo3.tex
\documentclass{article}

\begin{document}

\begin{tabular}{|c|c|c|} \hline
A & B & C \\ \hline \hline
1 & 2 & 3 \\ \hline% (this comment is to make sure to have nothing before \input)
\input{foo4}
%%%%%% end of foo3.tex

%%%%%% begin of foo4.tex
\end{tabular}

\end{document}
%%%%%% end of foo4.tex

The output generated by `latex foo3` is the following:

 -------------
 | A | B | C |
 -------------
 | 1 | 2 | 3 |
 -------------
 |   |

It seems to me that \input produces some extra stuff (before \end{tabular})
which is interpreted as the contents of a new row. Am I right, or have I done
something wrong ?

Thank you in advance for any help

Gregoire