% This macro source file is from the four volume series
% "TeX in Practice" by Stephan von Bechtolsheim, published
% 1993 by Springer-Verlag, New York.
% Copyright 1993 Stephan von Bechtolsheim.
% No warranty or liability is assumed.
% This macro may be copied freely if no fees other than
% media cost or shipping charges are charged and as long
% as this copyright and the following source code itself
% is not changed. Please see the series for further information.
%
% Version: 1.0
% Date: May 1, 1993
%
%
% This source code is documented in 29.7.1, p. III-528.
% Original source in file "io2.TEX", starting line 1941.
\wlog{L: "comfiles.tip" ["io2.TEX," l. 1941, p. III-528]}%
% This file DOES belong to format "texip."
\InputD{compst.tip}
\InputD{verb-bas.tip}
\InputD{fexist.tip}
\InputD{endrec.tip}
\catcode`\@ = 11
\newcount\@CompareFilesResult
\newread\@ReadCompareOne
\newread\@ReadCompareTwo
\def\CompareFilesConditional #1#2{% 
    TT\fi
    \if\FileExistsConditional{#1}%
    \else
        \errmessage{\string\CompareFilesConditional: first file "#1"
            does not exist.}% 
    \fi
    \if\FileExistsConditional{#2}%
    \else
        \errmessage{\string\CompareFilesConditional: second file "#2"
            does not exist.}% 
    \fi
    \global\@CompareFilesResult = 0
    \begingroup
    \MkOthers
    \openin\@ReadCompareOne = #1
    \openin\@ReadCompareTwo = #2
    \@CompareFiles
}

\def\@CompareFiles{% 
    \read\@ReadCompareOne to \@CompareOneString
    \read\@ReadCompareTwo to \@CompareTwoString
    \ifeof\@ReadCompareOne
        \ifeof\@ReadCompareOne
            \global\@CompareFilesResult = 1
        \else
            \global\@CompareFilesResult = 2
        \fi
    \else
        \ifeof\@ReadCompareOne
            \global\@CompareFilesResult = 2
        \else
            \ifx\@CompareOneString\@CompareTwoString
            \else
                \global\@CompareFilesResult = 2
            \fi
        \fi
    \fi
    \RecursionMacroEnd
        {\ifnum \@CompareFilesResult = 0\relax}% 
        {\@CompareFiles}{\@EndCompareFiles}% 
}
\def\@EndCompareFiles{% 
    \endgroup
    \closein\@ReadCompareOne
    \closein\@ReadCompareTwo
    \ifnum\@CompareFilesResult = 1
}
\catcode`\@ = 12