(eplain.info)Auxiliary files

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Enter node , (file) or (file)node

7.10 Auxiliary files
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It is common to write some information out to a file to be used on a
subsequent run. But when it is time to read the file again, you only
want to do so if the file actually exists. '\testfileexistence' is given
an argument which is appended to '\jobname', and sets the conditional
'\iffileexists' appropriately. For example:

     \testfileexistence{toc}%
     \iffileexists
        \input \jobname.toc
     \fi

   '\testfileexistence' takes an optional parameter; when given, it will
override '\jobname' for the root part of the file name. For example, if
you want to test for the file 'answers.aux', you can do this with the
following:

     \testfileexistence[answers]{aux}%
     \iffileexists
        \input answers.aux
     \fi