README file for package snapshot 2.14 [2020/06/17]

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========================================================================
                               CONTENTS
I.   OVERVIEW
II.  REMARKS ON THIS RELEASE
II.  CHANGE LOG

========================================================================
I. OVERVIEW

Complete documentation of all package options is available in
snapshot.pdf.

Typical usage involves the following steps:

1. Add a \RequirePackage statement at the top of the document:

       \RequirePackage{snapshot}
       \documentclass{article}

       \usepackage{graphicx}

       \begin{document}

       hello, world

       \end{document}

   Note that snapshot should be the very first thing loaded, even
   before the \documentclass.  Otherwise snapshot will not be able to
   capture the information for the document class and any packages
   loaded inside it.

2. Run LaTeX on the document. This will produce a dependency list in a
   file \jobname.dep.

3. Insert the .dep file at the top of the document, before
   \documentclass. The following example shows what you would
   typically end up with for a document that used the article
   documentclass and the graphicx package:

       \RequirePackage{snapshot}

       \RequireVersions{
         *{application}{pdfTeX}  {0000/00/00 v1.40.21}
         *{format} {LaTeX2e}     {2020-02-02 v2.e}
         *{package}{snapshot}    {2020/06/17 v2.14}
         *{class}  {article}     {2019/12/20 v1.4l}
         *{file}   {size10.clo}  {2019/12/20 v1.4l}
         *{package}{graphicx}    {2019/11/30 v1.2a}
         *{package}{keyval}      {2014/10/28 v1.15}
         *{package}{graphics}    {2019/11/30 v1.4a}
         *{package}{trig}        {2016/01/03 v1.10}
         *{file}   {graphics.cfg}{2016/06/04 v1.11}
         *{file}   {dvips.def}   {2017/06/20 v3.1d}
         *{file}   {l3backend-dvips.def}{2020-05-05 v3}
       }

       \documentclass{article}
       [...]

   Now each time you recompile the document, snapshot will compare the
   list of files actually loaded against the list recorded in
   \RequireVersions and warn you of any changes.

========================================================================
II. REMARKS ON THIS RELEASE

Since the snapshot package was originally released, there has been a
tremendous amount of evolution among TeX engines (what snapshot calls
the "application").  In addition to the introduction of two major new
engines, three other engines that were once distinct have effectively
merged.  The algorithm for detecting the identify of the engine has
been updated to reflect the state of the TeX world as reflected in TeX
Live 2020.

COMPATIBILITY NOTE: As a result of these improvements, the
*{application} entry of your documents will almost certainly change.
The snapshot package does not warn of changes in this entry, but if
you have an external application that makes use of this information,
you will probably need to update it.

========================================================================
III. CHANGE LOG

2020-06-17 snapshot.dtx v2.14
    -- Added code to detect the aleph, ptex, eptex, uptex, euptex,
       luatex, and xetex engines in addition to etex, pdftex, and
       pdfetex.  Also distinguish between the various engines which
       incorporate the eTeX extensions.
    -- Made snapshot more tolerant of macros in the optional argument
       to \Provides... declarations.