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<h1 class="settitle">A Directory Structure for TeX Files</h1>
<div class="node">
<p><hr>
<a name="Top"></a>
Next:&nbsp;<a rel="next" accesskey="n" href="#Introduction">Introduction</a>,
Up:&nbsp;<a rel="up" accesskey="u" href="#dir">(dir)</a>

</div>

<h2 class="unnumbered">A Directory Structure for TeX Files</h2>

<p>Copyright &copy; 1994, 1995, 1996, 1997, 1998, 1999, 2003, 2004
TeX Users Group.

   <p>Permission to use, copy, and distribute this document <em>without
modification</em> for any purpose and without fee is hereby granted,
provided that this notice appears in all copies.  It is provided &ldquo;as
is&rdquo; without expressed or implied warranty.

   <p>Permission is granted to copy and distribute modified versions of this
document under the conditions for verbatim copying, provided that the
modifications are clearly marked and the document is not represented as
the official one.

   <p>This document is available on any CTAN host
(see Appendix&nbsp;<!-- /@w --><a href="#Related-references">Related references</a>). 
Please send questions or suggestions by email to
<a href="mailto:tds@tug.org">tds@tug.org</a>.  We welcome all comments.   This is version
1.1.

<ul class="menu">
<li><a accesskey="1" href="#Introduction">Introduction</a>
<li><a accesskey="2" href="#General">General</a>
<li><a accesskey="3" href="#Top_002dlevel-directories">Top-level directories</a>
<li><a accesskey="4" href="#Summary">Summary</a>
<li><a accesskey="5" href="#Unspecified-pieces">Unspecified pieces</a>
<li><a accesskey="6" href="#Implementation-issues">Implementation issues</a>
<li><a accesskey="7" href="#Is-there-a-better-way_003f">Is there a better way?</a>
<li><a accesskey="8" href="#Related-references">Related references</a>
<li><a accesskey="9" href="#Contributors">Contributors</a>

</li></ul>
<p>--- The Detailed Node Listing ---

<p>Introduction

</p>
<ul class="menu">
<li><a href="#History">History</a>
<li><a href="#The-role-of-the-TDS">The role of the TDS</a>
<li><a href="#Conventions">Conventions</a>

</li></ul>
<p>General

</p>
<ul class="menu">
<li><a href="#Subdirectory-searching">Subdirectory searching</a>
<li><a href="#Rooting-the-tree">Rooting the tree</a>
<li><a href="#Local-additions">Local additions</a>
<li><a href="#Duplicate-filenames">Duplicate filenames</a>

</li></ul>
<p>Top-level directories

</p>
<ul class="menu">
<li><a href="#Macros">Macros</a>
<li><a href="#Fonts">Fonts</a>
<li><a href="#Non_002dfont-Metafont-files">Non-font Metafont files</a>
<li><a href="#MetaPost">MetaPost</a>
<li><a href="#BibTeX">BibTeX</a>
<li><a href="#Scripts">Scripts</a>
<li><a href="#Documentation">Documentation</a>

</li></ul>
<p>Macros

</p>
<ul class="menu">
<li><a href="#Extensions">Extensions</a>

</li></ul>
<p>Fonts

</p>
<ul class="menu">
<li><a href="#Font-bitmaps">Font bitmaps</a>
<li><a href="#Valid-font-bitmaps">Valid font bitmaps</a>

</li></ul>
<p>Summary

</p>
<ul class="menu">
<li><a href="#Documentation-tree-summary">Documentation tree summary</a>

</li></ul>
<p>Unspecified pieces

</p>
<ul class="menu">
<li><a href="#Portable-filenames">Portable filenames</a>

</li></ul>
<p>Implementation issues

</p>
<ul class="menu">
<li><a href="#Adoption-of-the-TDS">Adoption of the TDS</a>
<li><a href="#More-on-subdirectory-searching">More on subdirectory searching</a>
<li><a href="#Example-implementation_002dspecific-trees">Example implementation-specific trees</a>

</li></ul>
<p>Example implementation-specific trees

</p>
<ul class="menu">
<li><a href="#AmiWeb2c-2_002e0">AmiWeb2c 2.0</a>
<li><a href="#Public-DECUS-TeX">Public DECUS TeX</a>
<li><a href="#Web2c-7">Web2c 7</a>

</li></ul>
<p>Is there a better way?

</p>
<ul class="menu">
<li><a href="#Macro-structure">Macro structure</a>
<li><a href="#Font-structure">Font structure</a>
<li><a href="#Documentation-structure">Documentation structure</a>

</li></ul>
<p>Font structure

</p>
<ul class="menu">
<li><a href="#Font-file-type-location">Font file type location</a>
<li><a href="#Mode-and-resolution-location">Mode and resolution location</a>
<li><a href="#Modeless-bitmaps">Modeless bitmaps</a>

   </ul>

<div class="node">
<p><hr>
<a name="Introduction"></a>
Next:&nbsp;<a rel="next" accesskey="n" href="#General">General</a>,
Previous:&nbsp;<a rel="previous" accesskey="p" href="#Top">Top</a>,
Up:&nbsp;<a rel="up" accesskey="u" href="#Top">Top</a>

</div>

<h2 class="chapter">1 Introduction</h2>

<p>TeX is a powerful, flexible typesetting system used by many people
around the world.  It is extremely portable and runs on virtually all
operating systems.  One unfortunate side effect of TeX's flexibility,
however, is that there has been no single &ldquo;right&rdquo; way to install it. 
This has resulted in many sites having different installed arrangements.

   <p>The primary purpose of this document is to describe a standard TeX
Directory Structure (TDS): a directory hierarchy for macros,
fonts, and the other implementation-independent TeX system files.  As
a matter of practicality, this document also suggests ways to
incorporate the rest of the TeX files into a single structure.  The
TDS has been designed to work on all modern systems.  In
particular, the Technical Working Group (TWG) believes it is usable
under MacOS, MS-DOS, OS/2, Unix, VMS, and
Windows NT.  We hope that administrators and developers of both
free and commercial TeX implementations will adopt this standard.

   <p>This document is intended both for the TeX system administrator at a
site and for people preparing TeX distributions&mdash;everything from a
complete runnable system to a single macro or style file. It may also
help TeX users find their way around systems organized this way.  It
is not a tutorial: we necessarily assume knowledge of the many parts of
a working TeX system. If you are unfamiliar with any of the programs
or file formats we refer to, consult the references in
Appendix&nbsp;<!-- /@w --><a href="#Related-references">Related references</a>.

<ul class="menu">
<li><a accesskey="1" href="#History">History</a>
<li><a accesskey="2" href="#The-role-of-the-TDS">The role of the TDS</a>
<li><a accesskey="3" href="#Conventions">Conventions</a>
</ul>

<div class="node">
<p><hr>
<a name="History"></a>
Next:&nbsp;<a rel="next" accesskey="n" href="#The-role-of-the-TDS">The role of the TDS</a>,
Up:&nbsp;<a rel="up" accesskey="u" href="#Introduction">Introduction</a>

</div>

<h3 class="section">1.1 History</h3>

<p>Version 1.0 of the TDS was released in February 2003.

   <p>Version 1.1 was released in June 2004, with the following non-editorial
changes:

     <ul>
<li>Inputs for TeX extensions included under <samp><span class="file">tex</span></samp>, instead
      of in their own top-level directories (Section&nbsp;<!-- /@w --><a href="#Extensions">Extensions</a>)
<li>New top-level directory <samp><span class="file">scripts</span></samp> (Section&nbsp;<!-- /@w --><a href="#Scripts">Scripts</a>). 
<li>New subdirectories <samp><span class="file">lig</span></samp>, <samp><span class="file">opentype</span></samp>,
      <samp><span class="file">truetype</span></samp>, and <samp><span class="file">type3</span></samp> under <samp><span class="file">fonts</span></samp>
      (Section&nbsp;<!-- /@w --><a href="#Fonts">Fonts</a>). 
<li>`<samp><span class="samp">enc</span></samp>',
<samp><span class="file">lig</span></samp>, and <samp><span class="file">map</span></samp> all use
      <samp><var>syntax</var><span class="file">/</span><var>package</var></samp> subdirectories
      (Section&nbsp;<!-- /@w --><a href="#Fonts">Fonts</a>). 
<li>`<samp><span class="samp">pfm</span></samp>' files specified to go under <samp><span class="file">type1</span></samp>,
and
      <samp><span class="file">inf</span></samp> files under <samp><span class="file">afm</span></samp> (Section&nbsp;<!-- /@w --><a href="#Fonts">Fonts</a>). 
</ul>

<div class="node">
<p><hr>
<a name="The-role-of-the-TDS"></a>
Next:&nbsp;<a rel="next" accesskey="n" href="#Conventions">Conventions</a>,
Previous:&nbsp;<a rel="previous" accesskey="p" href="#History">History</a>,
Up:&nbsp;<a rel="up" accesskey="u" href="#Introduction">Introduction</a>

</div>

<h3 class="section">1.2 The role of the TDS</h3>

<p>The role of the TDS is to stabilize the organization of
TeX-related software packages that are installed and in use, possibly
on multiple platforms simultaneously.

   <p>At first glance, it may seem that the Comprehensive TeX Archive
Network (CTAN) fulfills at least part of this role, but this is
not the case.  The role of CTAN is to simplify archiving and
distribution, not installation and use.

   <p>In fact, the roles of the TDS and CTAN are frequently in
conflict, as we will see.  For distribution, many different types of
files must be combined into a single unit; for use, it is traditional to
segregate files (even similar files) from a single package into
separate, occasionally distant, directories.

<div class="node">
<p><hr>
<a name="Conventions"></a>
Previous:&nbsp;<a rel="previous" accesskey="p" href="#The-role-of-the-TDS">The role of the TDS</a>,
Up:&nbsp;<a rel="up" accesskey="u" href="#Introduction">Introduction</a>

</div>

<h3 class="section">1.3 Conventions</h3>

<p>In this document, <samp><span class="file">/</span></samp> is used to separate filename components;
for example, <samp><span class="file">texmf/fonts</span></samp>.  This is the Unix convention but the
ideas are in no way Unix-specific.

   <p>In this document, &ldquo;TeX&rdquo; generally means the TeX system, including
Metafont, DVI drivers, utilities, etc., not just the TeX
program itself.

   <p>The word &ldquo;package&rdquo; in this document has its usual meaning: a set of
related files distributed, installed, and maintained as a unit.  This is
<em>not</em> a LaTeX2e package, which is a style file supplementing
a document class.

   <p>We use the following typographic conventions:

     <ul>
<li>`<samp><span class="samp">literal</span></samp>'
Literal text such as <samp><span class="file">filename</span></samp> is
typeset in typewriter type.

     <li>`<samp><var>replaceable</var></samp>'
Replaceable text such as
<samp><var>package</var></samp>, identifying a class of things, is typeset in
italics inside angle brackets.

   </ul>

<div class="node">
<p><hr>
<a name="General"></a>
Next:&nbsp;<a rel="next" accesskey="n" href="#Top_002dlevel-directories">Top-level directories</a>,
Previous:&nbsp;<a rel="previous" accesskey="p" href="#Introduction">Introduction</a>,
Up:&nbsp;<a rel="up" accesskey="u" href="#Top">Top</a>

</div>

<h2 class="chapter">2 General</h2>

<p>This section describes common properties throughout the TDS tree.

<ul class="menu">
<li><a accesskey="1" href="#Subdirectory-searching">Subdirectory searching</a>
<li><a accesskey="2" href="#Rooting-the-tree">Rooting the tree</a>
<li><a accesskey="3" href="#Local-additions">Local additions</a>
<li><a accesskey="4" href="#Duplicate-filenames">Duplicate filenames</a>
</ul>

<div class="node">
<p><hr>
<a name="Subdirectory-searching"></a>
Next:&nbsp;<a rel="next" accesskey="n" href="#Rooting-the-tree">Rooting the tree</a>,
Up:&nbsp;<a rel="up" accesskey="u" href="#General">General</a>

</div>

<h3 class="section">2.1 Subdirectory searching</h3>

<p>Older TeX installations store large numbers of related files in single
directories, for example, all <samp><span class="file">TFM</span></samp> files and/or all TeX
input files.

   <p>This monolithic arrangement hinders maintenance of a TeX system: it
is difficult to determine what files are used by what packages, what
files need to be updated when a new version is installed, or what files
should be deleted if a package is removed.  It is also a source of error
if two or more packages happen to have input files with the same name.

   <p>Therefore, the TWG felt each package should be in a separate
directory. But we recognized that explicitly listing all directories to
be searched would be unbearable.  A site may wish to install dozens of
packages.  Aside from anything else, listing that many directories would
produce search paths many thousands of characters long, overflowing the
available space on some systems.

   <p>Also, if all directories are explicitly listed, installing or removing a
new package would mean changing a path as well as installing or removing
the actual files.  This would be a time-consuming and error-prone
operation, even with implementations that provide some way to specify
the directories to search at runtime.  On systems without runtime
configuration, it would require recompiling software, an intolerable
burden.

   <p>As a result, the TWG concluded that a comprehensive TDS
requires implementations to support some form of implicit subdirectory
searching.  More precisely, implementations must make it possible to
specify that TeX, Metafont, and their companion utilities search in both
a specified directory and recursively through all subdirectories of that
directory when looking for an input file.  Other forms of subdirectory
searching, for example recursive-to-one-level searches, may also be
provided.  We encourage implementors to provide subdirectory searching
at the option of the installer and user for all paths.

   <p>The TDS does not specify a syntax for specifying recursive
searching, but we encourage implementors to provide interoperability
(see Section&nbsp;<!-- /@w --><a href="#More-on-subdirectory-searching">More on subdirectory searching</a>).

<div class="node">
<p><hr>
<a name="Rooting-the-tree"></a>
Next:&nbsp;<a rel="next" accesskey="n" href="#Local-additions">Local additions</a>,
Previous:&nbsp;<a rel="previous" accesskey="p" href="#Subdirectory-searching">Subdirectory searching</a>,
Up:&nbsp;<a rel="up" accesskey="u" href="#General">General</a>

</div>

<h3 class="section">2.2 Rooting the tree</h3>

<p>In this document, we shall designate the root TDS directory by
<samp><span class="file">texmf</span></samp> (for &ldquo;TeX and Metafont&rdquo;). We recommend using that name
where possible, but the actual name of the directory is up to the
installer. On PC networks, for example, this could map to a
logical drive specification such as <samp><span class="file">T:</span></samp>.

   <p>Similarly, the location of this directory on the system is
site-dependent.  It may be at the root of the file system; on Unix
systems, <samp><span class="file">/usr/local/share</span></samp>, <samp><span class="file">/usr/local</span></samp>,
<samp><span class="file">/usr/local/lib</span></samp>, and <samp><span class="file">/opt</span></samp> are common choices.

   <p>The name <samp><span class="file">texmf</span></samp> was chosen for several reasons: it reflects the fact
that the directory contains files pertaining to an entire TeX system
(including Metafont, MetaPost, BibTeX, etc.), not just TeX itself; and it
is descriptive of a generic installation rather than a particular
implementation.

   <p>A site may choose to have more than one TDS hierarchy installed
(for example, when installing an upgrade). This is perfectly legitimate.

<div class="node">
<p><hr>
<a name="Local-additions"></a>
Next:&nbsp;<a rel="next" accesskey="n" href="#Duplicate-filenames">Duplicate filenames</a>,
Previous:&nbsp;<a rel="previous" accesskey="p" href="#Rooting-the-tree">Rooting the tree</a>,
Up:&nbsp;<a rel="up" accesskey="u" href="#General">General</a>

</div>

<h3 class="section">2.3 Local additions</h3>

<p>The TDS cannot specify precisely when a package is or is not a
&ldquo;local addition&rdquo;. Each site must determine this according to its own
conventions.  At the two extremes, one site might wish to consider
&ldquo;nonlocal&rdquo; all files not acquired as part of the installed TeX
distribution; another site might consider &ldquo;local&rdquo; only those files
that were actually developed at the local site and not distributed
elsewhere.

   <p>We recognize two common methods for local additions to a distributed
<samp><span class="file">texmf</span></samp> tree. Both have their place; in fact, some sites employ
both simultaneously:

     <ol type=1 start=1>

     <li>A completely separate tree which is a TDS structure
itself; for example, <samp><span class="file">/usr/local/umbtex</span></samp> at the University of
Massachusetts at Boston. This is another example of the multiple
<samp><span class="file">texmf</span></samp> hierarchies mentioned in the previous section.

     <li>A directory named <samp><span class="file">local</span></samp> at any appropriate level, for
example, in the <samp><var>format</var></samp>, <samp><var>package</var></samp>, and
<samp><var>supplier</var></samp> directories discussed in the following sections. 
The TDS reserves the directory name <samp><span class="file">local</span></samp> for this
purpose.

     <p>We recommend using <samp><span class="file">local</span></samp> for site-adapted configuration files,
such as <samp><span class="file">language.dat</span></samp> for the Babel package or <samp><span class="file">graphics.cfg</span></samp>
for the graphics package.  Unmodified configuration files from a package
should remain in the package directory. The intent is to separate
locally modified or created files from distribution files, to ease
installing new releases.

        </ol>

   <p>One common case of local additions is dynamically generated files, e.g.,
PK fonts by the <samp><span class="file">mktexpk</span></samp> script (which originated in
Dvips as <samp><span class="file">MakeTeXPK</span></samp>).  A site may store the
generated files directly in any of:
     <ul>
<li>their standard location in the main TDS tree (if it can be
made globally writable);

     <li>an alternative location in the main TDS tree (for
example, under <samp><span class="file">texmf/fonts/tmp</span></samp>);

     <li>a second complete TDS tree (as outlined above);

     <li>any other convenient directory (perhaps under
<samp><span class="file">/var</span></samp>, for example <samp><span class="file">/var/spool/fonts</span></samp>).

   </ul>

   <p>No one solution will be appropriate for all sites.

<div class="node">
<p><hr>
<a name="Duplicate-filenames"></a>
Previous:&nbsp;<a rel="previous" accesskey="p" href="#Local-additions">Local additions</a>,
Up:&nbsp;<a rel="up" accesskey="u" href="#General">General</a>

</div>

<h3 class="section">2.4 Duplicate filenames</h3>

<p>Different files by the same name may exist in a TDS tree. The
TDS generally leaves unspecified which of two files by the same
name in a search path will be found, so generally the only way to
reliably find a given file is for it to have a unique name.  However,
the TDS requires implementations to support the following
exceptions:

     <ul>
<li>Names of TeX input files must be unique within each first-level
subdirectory of <samp><span class="file">texmf/tex</span></samp> and <samp><span class="file">texmf/tex/generic</span></samp>, but not
within all of <samp><span class="file">texmf/tex</span></samp>; i.e., different TeX formats may have
files by the same name. (Section&nbsp;<!-- /@w --><a href="#Macros">Macros</a> discusses this
further.)  Thus, no single format-independent path specification, such
as a recursive search beginning at <samp><span class="file">texmf/tex</span></samp> specifying no other
directories, suffices.  So implementations must provide format-dependent
path specifications, for example via wrapper scripts or configuration
files.

     <li>Many font files will have the same name (e.g., <samp><span class="file">cmr10.pk</span></samp>),
as discussed in Section&nbsp;<!-- /@w --><a href="#Valid-font-bitmaps">Valid font bitmaps</a>.  Implementations
must distinguish these files by mode and resolution.

   </ul>

   <p>All implementations we know of already have these capabilities.

   <p>One place where duplicate names are likely to occur is not an exception:

     <ul>
<li>Names of Metafont input files (as opposed to bitmaps) must be unique
within all of <samp><span class="file">texmf/fonts</span></samp>. In practice, this is a problem with
some variants of Computer Modern which contain slightly modified files
named <samp><span class="file">punct.mf</span></samp>, <samp><span class="file">romanl.mf</span></samp>, and so on. We believe the only
feasible solution is to rename the derivative files to be
unique.

   </ul>

<div class="node">
<p><hr>
<a name="Top-level-directories"></a>
<a name="Top_002dlevel-directories"></a>
Next:&nbsp;<a rel="next" accesskey="n" href="#Summary">Summary</a>,
Previous:&nbsp;<a rel="previous" accesskey="p" href="#General">General</a>,
Up:&nbsp;<a rel="up" accesskey="u" href="#Top">Top</a>

</div>

<h2 class="chapter">3 Top-level directories</h2>

<p>The directories under the <samp><span class="file">texmf</span></samp> root identify the major components of
a TeX system (see Section&nbsp;<!-- /@w --><a href="#Summary">Summary</a> for a summary).  A site
may omit any unneeded directories.

   <p>Although the TDS by its nature can specify precise locations only
for implementation-independent files, we recognize that installers may
well wish to place other files under <samp><span class="file">texmf</span></samp> to simplify administration
of the TeX tree, especially if it is maintained by someone other than
the system administrator.  Therefore, additional top-level directories
may be present.

   <p>The top-level directories specified by the TDS are:

     <ul>
<li>`<samp><span class="samp">tex</span></samp>'
for TeX files (Section&nbsp;<!-- /@w --><a href="#Macros">Macros</a>).

     <li>`<samp><span class="samp">fonts</span></samp>'
for font-related files (Section&nbsp;<!-- /@w --><a href="#Fonts">Fonts</a>).

     <li>`<samp><span class="samp">metafont</span></samp>'
for Metafont files which are not fonts (Section&nbsp;<!-- /@w --><a href="#Non_002dfont-Metafont-files">Non-font Metafont files</a>).

     <li>`<samp><span class="samp">metapost</span></samp>'
for MetaPost files (Section&nbsp;<!-- /@w --><a href="#MetaPost">MetaPost</a>).

     <li>`<samp><span class="samp">bibtex</span></samp>'
for BibTeX files (Section&nbsp;<!-- /@w --><a href="#BibTeX">BibTeX</a>).

     <li>`<samp><span class="samp">scripts</span></samp>'
for platform-independent executables (Section&nbsp;<!-- /@w --><a href="#Scripts">Scripts</a>).

     <li>`<samp><span class="samp">doc</span></samp>'
for user documentation (Section&nbsp;<!-- /@w --><a href="#Documentation">Documentation</a>).

     <li>`<samp><span class="samp">source</span></samp>'
for sources.  This includes both traditional
program sources (for example, Web2C sources go in
<samp><span class="file">texmf/source/web2c</span></samp>) and, e.g., LaTeX <samp><span class="file">dtx</span></samp> sources (which
go in <samp><span class="file">texmf/source/latex</span></samp>). The TDS leaves unspecified any
structure under <samp><span class="file">source</span></samp>.

     <p><samp><span class="file">source</span></samp> is intended for files which are not needed at runtime by
any TeX program; it should not be included in any search path. For
example, <samp><span class="file">plain.tex</span></samp> does not belong under <samp><span class="file">texmf/source</span></samp>,
even though it is a &ldquo;source file&rdquo; in the sense of not being derived
from another file. (It goes in <samp><span class="file">texmf/tex/plain/base</span></samp>, as explained
in Section&nbsp;<!-- /@w --><a href="#Macros">Macros</a>).

     <li>`<samp><var>implementation</var></samp>'
for implementations (examples:
<samp><span class="file">emtex</span></samp>, <samp><span class="file">vtex</span></samp>, <samp><span class="file">web2c</span></samp>), to be used for whatever
purpose deemed suitable by the implementor or TeX administrator. 
That is, files that cannot be shared between implementations, such as
pool files (<samp><span class="file">tex.pool</span></samp>) and memory dump files (<samp><span class="file">plain.fmt</span></samp>) go
here, in addition to implementation-wide configuration files.  See
Section&nbsp;<!-- /@w --><a href="#Example-implementation_002dspecific-trees">Example implementation-specific trees</a> for examples of
real <samp><var>implementation</var></samp> trees.

     <p>Such implementation-specific configuration files should <em>not</em>
be located using the main TeX input search path (e.g.,
<samp><span class="file">TEXINPUTS</span></samp>).  This must be reserved for files actually read by a
TeX engine.  See Section&nbsp;<!-- /@w --><a href="#Extensions">Extensions</a>.

     <li>`<samp><var>program</var></samp>'
for program-specific input and
configuration files for any TeX-related programs (examples:
<samp><span class="file">mft</span></samp>, <samp><span class="file">dvips</span></samp>).  In fact, the <samp><span class="file">tex</span></samp>, <samp><span class="file">metafont</span></samp>,
<samp><span class="file">metapost</span></samp>, and <samp><span class="file">bibtex</span></samp> items above may all be seen as
instances of this case.

   </ul>

<ul class="menu">
<li><a accesskey="1" href="#Macros">Macros</a>
<li><a accesskey="2" href="#Fonts">Fonts</a>
<li><a accesskey="3" href="#Non_002dfont-Metafont-files">Non-font Metafont files</a>
<li><a accesskey="4" href="#MetaPost">MetaPost</a>
<li><a accesskey="5" href="#BibTeX">BibTeX</a>
<li><a accesskey="6" href="#Scripts">Scripts</a>
<li><a accesskey="7" href="#Documentation">Documentation</a>
</ul>

<div class="node">
<p><hr>
<a name="Macros"></a>
Next:&nbsp;<a rel="next" accesskey="n" href="#Fonts">Fonts</a>,
Up:&nbsp;<a rel="up" accesskey="u" href="#Top_002dlevel-directories">Top-level directories</a>

</div>

<h3 class="section">3.1 Macros</h3>

<p>TeX macro files shall be stored in separate directories, segregated
by TeX format and package name (we use `format' in its traditional
TeX sense to mean a usefully <samp><span class="file">\dump</span></samp>-able package):
<pre class="example">     texmf/tex/<var>format</var>/<var>package</var>/
</pre>
     <ul>
<li>`<samp><var>format</var></samp>'
is a format name (examples: <samp><span class="file">amstex</span></samp>,
<samp><span class="file">latex</span></samp>, <samp><span class="file">plain</span></samp>, <samp><span class="file">texinfo</span></samp>).

     <p>The TDS allows distributions that can be used as either formats or
packages (e.g., Texinfo, Eplain) to be stored at either level, at the
option of the format author or TeX administrator. We recommend that
packages used as formats at a particular site be stored at the
<samp><var>format</var></samp> level: by adjusting the TeX inputs search path,
it will be straightforward to use them as macro packages under another
format, whereas placing them in another tree completely obscures their
use as a format.

     <p>The TDS reserves the following <samp><var>format</var></samp> names:

          <ul>
<li>`<samp><span class="samp">generic</span></samp>',
for input files that are useful across a wide
range of formats (examples: <samp><span class="file">null.tex</span></samp>, <samp><span class="file">path.sty</span></samp>). 
Generally, this means any format that uses the category codes of Plain
TeX and does not rely on any particular format.  This is in contrast
to those files which are useful only with Plain TeX (which go under
<samp><span class="file">texmf/tex/plain</span></samp>), e.g., <samp><span class="file">testfont.tex</span></samp> and <samp><span class="file">plain.tex</span></samp>
itself.

          <li>`<samp><span class="samp">local</span></samp>',
for local additions. See Section&nbsp;<!-- /@w --><a href="#Local-additions">Local additions</a>.

     </ul>

     <p>Thus, for almost every format, it is necessary to search at least the
<samp><var>format</var></samp> directory and then the <samp><span class="file">generic</span></samp> directory (in
that order).  Other directories may need to be searched as well,
depending on the format.  When using AMS-TeX, for example, the
<samp><span class="file">amstex</span></samp>, <samp><span class="file">plain</span></samp>, and <samp><span class="file">generic</span></samp> directories should be
searched, because AMS-TeX is compatible with Plain.

     <li>`<samp><var>package</var></samp>'
is a TeX package name (examples:
<samp><span class="file">babel</span></samp>, <samp><span class="file">texdraw</span></samp>).

     <p>In the case where a format consists of only a single file and has no
auxiliary packages, that file can simply be placed in the
<samp><var>format</var></samp> directory, instead of
<samp><var>format</var><span class="file">/base</span></samp>.  For example, Texinfo may go in
<samp><span class="file">texmf/tex/texinfo/texinfo.tex</span></samp>, not
<samp><span class="file">texmf/tex/texinfo/base/texinfo.tex</span></samp>.

     <p>The TDS reserves the following <samp><var>package</var></samp> names:

          <ul>
<li>`<samp><span class="samp">base</span></samp>',
for the base distribution of each format,
including files used by INITEX when dumping format files.  For
example, in the standard LaTeX distribution, the <samp><span class="file">ltx</span></samp> files
created during the build process.  Another example: the <samp><span class="file">.ini</span></samp>
driver files for formats used by TeX Live and other distributions.

          <li>`<samp><span class="samp">hyphen</span></samp>',
for hyphenation patterns, including the original
American English <samp><span class="file">hyphen.tex</span></samp>.  These are typically used only by
INITEX.  In most situations, this directory need exist only under the
<samp><span class="file">generic</span></samp> format.

          <li>`<samp><span class="samp">images</span></samp>',
for image input files, such as Encapsulated
PostScript figures. Although it is somewhat non-intuitive for these to
be under a directory named <samp><span class="file">tex</span></samp>, TeX needs to read these
files to glean bounding box or other information.  A mechanism for
sharing image inputs between TeX and other typesetting programs
(e.g., Interleaf, FrameMaker) is beyond the scope of the
TDS. In most situations, this directory need exist only under
the <samp><span class="file">generic</span></samp> format.

          <li>`<samp><span class="samp">local</span></samp>',
for local additions and configuration files. See
Section&nbsp;<!-- /@w --><a href="#Local-additions">Local additions</a>.

          <li>`<samp><span class="samp">misc</span></samp>',
for packages that consist of a single file.  An
administrator or package maintainer may create directories for
single-file packages at their discretion, instead of using <samp><span class="file">misc</span></samp>.

     </ul>

   </ul>

<ul class="menu">
<li><a accesskey="1" href="#Extensions">Extensions</a>
</ul>

<div class="node">
<p><hr>
<a name="Extensions"></a>
Up:&nbsp;<a rel="up" accesskey="u" href="#Macros">Macros</a>

</div>

<h4 class="subsection">3.1.1 Extensions</h4>

<p>TeX has spawned many companion and successor programs (&ldquo;engines&rdquo;),
such as PDFTeX, Omega, and others.  The TDS specifies
that the input files for such programs (using a TeX-like syntax) be
placed within the top-level <samp><span class="file">tex</span></samp> directory, either at the top
level or within a format subdirectory, even though the original TeX
program may not be able to read them.  For example:

<pre class="example">     texmf/tex/aleph
     texmf/tex/enctex
</pre>
   <p>This is a change from TDS&nbsp;<!-- /@w -->1.0, which specified top-level
<samp><var>extension</var></samp> directories for each such program.  We felt the
new approach is preferable, because:

     <ul>
<li>Authors of relevant packages typically make their code detect the
engine being used, and issue error messages or adapt to circumstances
appropriately.  Furthermore, as a package matures, it may support
multiple engines.  Thus, a package could conceivably be placed in any of
several top-level directories, at different times.  Putting all packages
under the top-level <samp><span class="file">tex</span></samp> directory provides a stable location over
time.

     <li>Users need to be able to switch between engines, and configuring
different search paths for each engine is difficult and error-prone.

   </ul>

   <p>Thus, in practice, having different top-level directories caused
difficulties for everyone involved&mdash;users, package authors, site
administrators, and system distributors.

   <p>Please contrast this approach with the <samp><var>implementation</var></samp>
top-level subdirectory (Section&nbsp;<!-- /@w --><a href="#Top_002dlevel-directories">Top-level directories</a>), which
is to be used for configuration files that (presumably) do not use
TeX syntax and in any case should not be found along the main TeX
input search path.

<div class="node">
<p><hr>
<a name="Fonts"></a>
Next:&nbsp;<a rel="next" accesskey="n" href="#Non_002dfont-Metafont-files">Non-font Metafont files</a>,
Previous:&nbsp;<a rel="previous" accesskey="p" href="#Macros">Macros</a>,
Up:&nbsp;<a rel="up" accesskey="u" href="#Top_002dlevel-directories">Top-level directories</a>

</div>

<h3 class="section">3.2 Fonts</h3>

<p>Font files are stored in separate directories, segregated by file type,
and then (in most cases) font supplier and typeface.  PK and
GF files need additional structure, as detailed in the next
section.

<pre class="example">     texmf/fonts/<var>type</var>/<var>supplier</var>/<var>typeface</var>/
     texmf/fonts/enc,lig,map/<var>subpath</var>/
</pre>
     <ul>
<li>`<samp><var>type</var></samp>'
is the type of font file. The TDS
reserves the following <samp><var>type</var></samp> names for common TeX file
types:

          <ul>
<li>`<samp><span class="samp">afm</span></samp>',
for Adobe font metrics, and <samp><span class="file">inf</span></samp> files. 
<li>`<samp><span class="samp">gf</span></samp>',
for generic font bitmap files. 
<li>`<samp><span class="samp">opentype</span></samp>',
for OpenType fonts. 
<li>`<samp><span class="samp">pk</span></samp>',
for packed bitmap files. 
<li>`<samp><span class="samp">source</span></samp>',
for font sources (Metafont files, property lists, etc.). 
<li>`<samp><span class="samp">tfm</span></samp>',
for TeX font metric files. 
<li>`<samp><span class="samp">truetype</span></samp>',
for TrueType fonts. 
<li>`<samp><span class="samp">type1</span></samp>',
for PostScript Type 1 fonts (in <samp><span class="file">pfa</span></samp>,
      <samp><span class="file">pfb</span></samp>, or any other format), and <samp><span class="file">pfm</span></samp> files. 
<li>`<samp><span class="samp">type3</span></samp>',
for PostScript Type 3 fonts. 
<li>`<samp><span class="samp">vf</span></samp>',
for virtual fonts. 
</ul>

     <p>The TDS also reserves the names <samp><span class="file">enc</span></samp>, <samp><span class="file">lig</span></samp>, and
<samp><span class="file">map</span></samp> for font encoding, ligature, and mapping files, respectively. 
All of these directories are structured the same way, with
<samp><var>syntax</var></samp> subdirectories, and then <samp><var>package</var></samp>
subsubdirectories.  Each of these file types is intended to be searched
along its own recursively-searched path.  The names of the actual files
must be unique within their subtree, as usual.  Examples:
     <pre class="example">          fonts/map/dvipdfm/updmap/dvipdfm.map
          fonts/map/dvips/lm/lm.map
          fonts/enc/dvips/base/8r.enc
     </pre>
     <p>The Fontname and Dvips packages have more examples of the <samp><span class="file">enc</span></samp> and
<samp><span class="file">map</span></samp> types.  The <samp><span class="file">afm2pl</span></samp> program uses <samp><span class="file">lig</span></samp> files.

     <p><samp><span class="file">pfm</span></samp> files are included in the <samp><span class="file">type1</span></samp> directory, instead of
being given their own directory, for two reasons: 1)&nbsp;<!-- /@w -->a <samp><span class="file">.pfm</span></samp> file
is always an adjunct to a given <samp><span class="file">.pfb</span></samp> file; 2)&nbsp;<!-- /@w -->they must be
installed from the same directory for Windows programs other than TeX
to use them.

     <p><samp><span class="file">inf</span></samp> files are included in the <samp><span class="file">afm</span></samp> directory, since
an <samp><span class="file">inf</span></samp> and <samp><span class="file">afm</span></samp> file can be used to generate a <samp><span class="file">pfm</span></samp>. 
(Unfortunately, Adobe Type Manager and perhaps other software requires
that the <samp><span class="file">pfb</span></samp> be in the same directory as <samp><span class="file">afm</span></samp> and
<samp><span class="file">inf</span></samp> for installation.)

     <p>As usual, a site may omit any of these directories that are unnecessary. 
<samp><span class="file">gf</span></samp> is a particularly likely candidate for omission.

     <li>`<samp><var>supplier</var></samp>'
is a name identifying font source
(examples: <samp><span class="file">adobe</span></samp>, <samp><span class="file">ams</span></samp>, <samp><span class="file">public</span></samp>). The TDS
reserves the following <samp><var>supplier</var></samp> names:

          <ul>
<li>`<samp><span class="samp">ams</span></samp>',
for the American Mathematical Society's AMS-fonts
collection.

          <li>`<samp><span class="samp">local</span></samp>',
for local additions. See Section&nbsp;<!-- /@w --><a href="#Local-additions">Local additions</a>.

          <li>`<samp><span class="samp">public</span></samp>',
for freely redistributable fonts where the supplier
neither (1)&nbsp;<!-- /@w -->requested their own directory (e.g., <samp><span class="file">ams</span></samp>), nor
(2)&nbsp;<!-- /@w -->also made proprietary fonts (e.g., <samp><span class="file">adobe</span></samp>).  It does not
contain all extant freely distributable fonts, nor are all files therein
necessarily strictly public domain.

          <li>`<samp><span class="samp">tmp</span></samp>',
for dynamically-generated fonts, as is traditional on
some systems. It may be omitted if unnecessary, as usual.

     </ul>

     <li>`<samp><var>typeface</var></samp>'
is the name of a typeface family
(examples: <samp><span class="file">cm</span></samp>, <samp><span class="file">euler</span></samp>, <samp><span class="file">times</span></samp>). The TDS
reserves the following <samp><var>typeface</var></samp> names:

          <ul>
<li>`<samp><span class="samp">cm</span></samp>' (within <samp><span class="file">public</span></samp>),
for the 75 fonts defined in
<cite>Computers and Typesetting, Volume&nbsp;<!-- /@w -->E</cite>.

          <li>`<samp><span class="samp">latex</span></samp>' (within <samp><span class="file">public</span></samp>),
for those fonts distributed
with LaTeX in the base distribution.

          <li>`<samp><span class="samp">local</span></samp>',
for local additions. See Section&nbsp;<!-- /@w --><a href="#Local-additions">Local additions</a>.

     </ul>

   </ul>

   <p>Some concrete examples:
<pre class="example">     texmf/fonts/source/public/pandora/pnr10.mf
     texmf/fonts/tfm/public/cm/cmr10.tfm
     texmf/fonts/type1/adobe/utopia/putr.pfa
</pre>
   <p>For complete supplier and typeface name lists, consult
<cite>Filenames for TeX fonts</cite> (see Appendix&nbsp;<!-- /@w --><a href="#Related-references">Related references</a>).

<ul class="menu">
<li><a accesskey="1" href="#Font-bitmaps">Font bitmaps</a>
<li><a accesskey="2" href="#Valid-font-bitmaps">Valid font bitmaps</a>
</ul>

<div class="node">
<p><hr>
<a name="Font-bitmaps"></a>
Next:&nbsp;<a rel="next" accesskey="n" href="#Valid-font-bitmaps">Valid font bitmaps</a>,
Up:&nbsp;<a rel="up" accesskey="u" href="#Fonts">Fonts</a>

</div>

<h4 class="subsection">3.2.1 Font bitmaps</h4>

<p>Font bitmap files require two characteristics in addition to the above
to be uniquely identifiable: (1)&nbsp;<!-- /@w -->the type of device (i.e., mode) for
which the font was created; (2)&nbsp;<!-- /@w -->the resolution of the bitmap.

   <p>Following common practice, the TDS segregates fonts with
different device types into separate directories.  See <samp><span class="file">modes.mf</span></samp>
in Appendix&nbsp;<!-- /@w --><a href="#Related-references">Related references</a> for recommended mode names.

   <p>Some printers operate at more than one resolution (e.g., at 300<span class="dmn">dpi</span> and
600<span class="dmn">dpi</span>), but each such resolution will necessarily have a different
mode name. Nothing further is needed, since implicit in the TeX
system is the assumption of a single target resolution.

   <p>Two naming strategies are commonly used to identify the resolution of
bitmap font files.  On systems that allow long filenames (and in the
original Metafont program itself), the resolution is included in the
filename (e.g., <samp><span class="file">cmr10.300pk</span></samp>).  On systems which do not support
long filenames, fonts are generally segregated into directories by
resolution (e.g., <samp><span class="file">dpi300/cmr10.pk</span></samp>).

   <p>Because the TDS cannot require long filenames, we must use the
latter scheme for naming fonts. So we have two more subdirectory
levels under <samp><span class="file">pk</span></samp> and <samp><span class="file">gf</span></samp>:

<pre class="example">     texmf/fonts/pk/<var>mode</var>/<var>supplier</var>/<var>typeface</var>/dpi<var>nnn</var>/
     texmf/fonts/gf/<var>mode</var>/<var>supplier</var>/<var>typeface</var>/dpi<var>nnn</var>/
</pre>
     <ul>
<li>`<samp><var>mode</var></samp>'
is a name which identifies the device type
(examples: <samp><span class="file">cx</span></samp>, <samp><span class="file">ljfour</span></samp>, <samp><span class="file">modeless</span></samp>).  Usually, this is
the name of the Metafont mode used to build the PK file.  For fonts
rendered as bitmaps by a program that does not distinguish between
different output devices, the <samp><var>mode</var></samp> name shall be simply
<samp><span class="file">modeless</span></samp>.  The <samp><var>mode</var></samp> level shall not be omitted,
even if only a single mode happens to be in use.

     <li>`<samp><span class="samp">dpi</span><var>nnn</var></samp>'
specifies the resolution of the font
(examples: <samp><span class="file">dpi300</span></samp>, <samp><span class="file">dpi329</span></samp>).  <samp><span class="file">dpi</span></samp> stands for
dots per inch, i.e., pixels per inch. We recognize that pixels per
millimeter is used in many parts of the world, but dpi is too
traditional in the TeX world to consider changing now.

     <p>The integer <samp><var>nnn</var></samp> is to be calculated as if using Metafont
arithmetic and then rounded; i.e., it is the integer Metafont uses in its
output <samp><span class="file">gf</span></samp> filename.  We recognize small differences in the
resolution are a common cause of frustration among users, however, and
recommend implementors follow the level&nbsp;<!-- /@w -->0 DVI driver standard
(see Appendix&nbsp;<!-- /@w --><a href="#Related-references">Related references</a>) in bitmap font searches by
allowing a fuzz of +-0.2% (with a minimum of 1) in the
<samp><var>dpi</var></samp>.

   </ul>

   <p>Implementations may provide extensions to the basic naming scheme, such
as long filenames (as in the original Metafont) and font library files (as
in emTeX's <samp><span class="file">.fli</span></samp> files), provided that the basic scheme is also
supported.

<div class="node">
<p><hr>
<a name="Valid-font-bitmaps"></a>
Previous:&nbsp;<a rel="previous" accesskey="p" href="#Font-bitmaps">Font bitmaps</a>,
Up:&nbsp;<a rel="up" accesskey="u" href="#Fonts">Fonts</a>

</div>

<h4 class="subsection">3.2.2 Valid font bitmaps</h4>

<p>The TWG recognizes that the use of short filenames has many
disadvantages.  The most vexing is that it results in the creation of
dozens of different files with the same name.  At a typical site,
<samp><span class="file">cmr10.pk</span></samp> will be the filename for Computer Modern Roman 10<span class="dmn">pt</span> at
5&ndash;10 magnifications for 2&ndash;3 modes. (Section&nbsp;<!-- /@w --><a href="#Duplicate-filenames">Duplicate filenames</a> discusses duplicate filenames in general.)

   <p>To minimize this problem, we strongly recommend that PK files
contain enough information to identify precisely how they were created:
at least the mode, base resolution, and magnification used to create the
font.

   <p>This information is easy to supply: a simple addition to the local modes
used for building the fonts with Metafont will automatically provide the
required information.  If you have been using a local modes file derived
from (or that is simply) <samp><span class="file">modes.mf</span></samp> (see Appendix&nbsp;<!-- /@w --><a href="#Related-references">Related references</a>), the required information is already in your PK
files.  If not, a simple addition based on the code found in
<samp><span class="file">modes.mf</span></samp> can be made to your local modes file and the PK
files rebuilt.

<div class="node">
<p><hr>
<a name="Non-font-Metafont-files"></a>
<a name="Non_002dfont-Metafont-files"></a>
Next:&nbsp;<a rel="next" accesskey="n" href="#MetaPost">MetaPost</a>,
Previous:&nbsp;<a rel="previous" accesskey="p" href="#Fonts">Fonts</a>,
Up:&nbsp;<a rel="up" accesskey="u" href="#Top_002dlevel-directories">Top-level directories</a>

</div>

<h3 class="section">3.3 Non-font Metafont files</h3>

<p>Most Metafont input files are font programs or parts of font programs and
are thus covered by the previous section. However, a few non-font input
files do exist. Such files shall be stored in:

<pre class="example">     texmf/metafont/<var>package</var>/
</pre>
   <p><samp><var>package</var></samp> is the name of a
Metafont package (for example, <samp><span class="file">mfpic</span></samp>).

   <p>The TDS reserves the following <samp><var>package</var></samp> names:

     <ul>
<li>`<samp><span class="samp">base</span></samp>',
for the standard Metafont macro files as described in
<cite>The Metafontbook</cite>, such as <samp><span class="file">plain.mf</span></samp> and <samp><span class="file">expr.mf</span></samp>.

     <li>`<samp><span class="samp">local</span></samp>',
for local additions. See Section&nbsp;<!-- /@w --><a href="#Local-additions">Local additions</a>.

     <li>`<samp><span class="samp">misc</span></samp>',
for Metafont packages consisting of only a single file
(for example, <samp><span class="file">modes.mf</span></samp>).  An administrator or package maintainer
may create directories for single-file packages at their discretion,
instead of using <samp><span class="file">misc</span></samp>.

   </ul>

<div class="node">
<p><hr>
<a name="MetaPost"></a>
Next:&nbsp;<a rel="next" accesskey="n" href="#BibTeX">BibTeX</a>,
Previous:&nbsp;<a rel="previous" accesskey="p" href="#Non_002dfont-Metafont-files">Non-font Metafont files</a>,
Up:&nbsp;<a rel="up" accesskey="u" href="#Top_002dlevel-directories">Top-level directories</a>

</div>

<h3 class="section">3.4 MetaPost</h3>

<p>MetaPost is a picture-drawing language developed by John Hobby, derived
from Knuth's Metafont. Its primary purpose is to output Encapsulated PostScript
instead of bitmaps.

   <p>MetaPost input files and the support files for MetaPost-related utilities
shall be stored in:

<pre class="example">     texmf/metapost/<var>package</var>/
</pre>
   <p><samp><var>package</var></samp> is the name of a MetaPost package.  At the present
writing none exist, but the TWG thought it prudent to leave room
for contributed packages that might be written in the future.

   <p>The TDS reserves the following <samp><var>package</var></samp> names:

     <ul>
<li>`<samp><span class="samp">base</span></samp>',
for the standard MetaPost macro files, such as
<samp><span class="file">plain.mp</span></samp>, <samp><span class="file">mfplain.mp</span></samp>, <samp><span class="file">boxes.mp</span></samp>, and
<samp><span class="file">graph.mp</span></samp>.  This includes files used by INIMP when dumping mem
files containing preloaded macro definitions.

     <li>`<samp><span class="samp">local</span></samp>',
for local additions. See Section&nbsp;<!-- /@w --><a href="#Local-additions">Local additions</a>.

     <li>`<samp><span class="samp">misc</span></samp>',
for MetaPost packages consisting of only a single file. 
An administrator or package maintainer may create directories for
single-file packages at their discretion, instead of using <samp><span class="file">misc</span></samp>.

     <li>`<samp><span class="samp">support</span></samp>',
for additional input files required by MetaPost
utility programs, including a font map, a character adjustment table,
and a subdirectory containing low-level MetaPost programs for rendering
some special characters.

   </ul>

<div class="node">
<p><hr>
<a name="BibTeX"></a>
Next:&nbsp;<a rel="next" accesskey="n" href="#Scripts">Scripts</a>,
Previous:&nbsp;<a rel="previous" accesskey="p" href="#MetaPost">MetaPost</a>,
Up:&nbsp;<a rel="up" accesskey="u" href="#Top_002dlevel-directories">Top-level directories</a>

</div>

<h3 class="section">3.5 BibTeX</h3>

<p>BibTeX-related files shall be stored in:

<pre class="example">     texmf/bibtex/bib/<var>package</var>/
     texmf/bibtex/bst/<var>package</var>/
</pre>
   <p>The <samp><span class="file">bib</span></samp> directory is for BibTeX database (<samp><span class="file">.bib</span></samp>) files,
the <samp><span class="file">bst</span></samp> directory for style (<samp><span class="file">.bst</span></samp>) files.

   <p><samp><var>package</var></samp> is the name of a BibTeX package.  The
TDS reserves the following <samp><var>package</var></samp> names (the same
names are reserved under both <samp><span class="file">bib</span></samp> and <samp><span class="file">bst</span></samp>):

     <ul>
<li>`<samp><span class="samp">base</span></samp>',
for the standard BibTeX databases and styles, such
as <samp><span class="file">xampl.bib</span></samp>, <samp><span class="file">plain.bst</span></samp>.

     <li>`<samp><span class="samp">local</span></samp>',
for local additions. See Section&nbsp;<!-- /@w --><a href="#Local-additions">Local additions</a>.

     <li>`<samp><span class="samp">misc</span></samp>',
for BibTeX packages consisting of only a single
file.  An administrator or package maintainer may create directories for
single-file packages at their discretion, instead of using <samp><span class="file">misc</span></samp>.

   </ul>

<div class="node">
<p><hr>
<a name="Scripts"></a>
Next:&nbsp;<a rel="next" accesskey="n" href="#Documentation">Documentation</a>,
Previous:&nbsp;<a rel="previous" accesskey="p" href="#BibTeX">BibTeX</a>,
Up:&nbsp;<a rel="up" accesskey="u" href="#Top_002dlevel-directories">Top-level directories</a>

</div>

<h3 class="section">3.6 Scripts</h3>

<p>The top-level <samp><span class="file">scripts</span></samp> directory is for platform-independent
executables, such as Perl, Python, and shell scripts, and Java class
files.  Subdirectories under <samp><span class="file">scripts</span></samp> are package names.  This
eases creating distributions, by providing a common place for such
platform-independent programs.

   <p>The intent is not for all such directories to be added to a user's
command search path, which would be quite impractical.  Rather, these
executables are primarily for the benefit of wrapper scripts in whatever
executable directory a distribution may provide (which is not specified
by the TDS).

   <p>Truly auxiliary scripts which are invoked directly by other programs,
rather than wrapper scripts, may also be placed here.  That is,
<samp><span class="file">scripts</span></samp> also serves as a platform-independent analog of the
standard Unix <samp><span class="file">libexec</span></samp> directory.

   <p>We recommend using extensions specifying the language (such as
<samp><span class="file">.pl</span></samp>, <samp><span class="file">.py</span></samp>, <samp><span class="file">.sh</span></samp>) on these files, to help uniquely
identify the name.  Since the intent of the TDS is for programs
in <samp><span class="file">scripts</span></samp> not to be invoked directly by users, this poses no
inconvenience.

   <p>For example, in the TeX Live distribution, the ConTeXt user-level
program <samp><span class="file">texexec</span></samp> can exist as a small wrapper script in each
<samp><span class="file">bin/</span><var>platform</var><span class="file">/texexec</span></samp> (which is outside the
<samp><span class="file">texmf</span></samp> tree), which merely finds and calls
<samp><span class="file">texmf/scripts/context/perl/texexec.pl</span></samp>.

   <p>Examples:
<pre class="example">     scripts/context/perl/texexec.pl
     scripts/context/ruby/examplex.rb
     scripts/thumbpdf/thumbpdf.pl
</pre>
   <p>The TDS does not specify a location for platform-dependent
binary executables, whether auxiliary or user-level.

<div class="node">
<p><hr>
<a name="Documentation"></a>
Previous:&nbsp;<a rel="previous" accesskey="p" href="#Scripts">Scripts</a>,
Up:&nbsp;<a rel="up" accesskey="u" href="#Top_002dlevel-directories">Top-level directories</a>

</div>

<h3 class="section">3.7 Documentation</h3>

<p>Most packages come with some form of documentation: user manuals,
example files, programming guides, etc.  In addition, many independent
files not part of any macro or other package have been created to
describe various aspects of the TeX system.

   <p>The TDS specifies that these additional documentation files shall
be stored in a structure that parallels to some extent the
<samp><span class="file">fonts</span></samp> and <samp><span class="file">tex</span></samp> directories, as follows:

<pre class="example">     texmf/doc/<var>category</var>/...
</pre>
   <p><samp><var>category</var></samp> identifies the general topic of documentation
that resides below it; for example, a TeX format name (<samp><span class="file">latex</span></samp>),
program name (<samp><span class="file">bibtex</span></samp>, <samp><span class="file">tex</span></samp>), language (<samp><span class="file">french</span></samp>,
<samp><span class="file">german</span></samp>), a file format (<samp><span class="file">info</span></samp>, <samp><span class="file">man</span></samp>), or other system
components (<samp><span class="file">web</span></samp>, <samp><span class="file">fonts</span></samp>).

   <p>One possible arrangement is to organize <samp><span class="file">doc</span></samp> by language, with all
the other category types below that.  This helps users find
documentation in the language(s) in which they are fluent.  Neither this
nor any other particular arrangement is required, however.

   <p>Within each <samp><var>category</var></samp> tree for a TeX format, the
directory <samp><span class="file">base</span></samp> is reserved for base documentation distributed by
the format's maintainers.

   <p>The TDS reserves the following category names:

     <ul>
<li>`<samp><span class="samp">general</span></samp>',
for standalone documents not specific to any
particular program (for example, Joachim Schrod's <cite>Components
of TeX</cite>).

     <li>`<samp><span class="samp">help</span></samp>',
for meta-information, such as FAQ's,
the TeX Catalogue, etc.

     <li>`<samp><span class="samp">info</span></samp>',
for processed Texinfo documents.  (Info files, like
anything else, may also be stored outside the TDS, at the
installer's option.)

     <li>`<samp><span class="samp">local</span></samp>',
for local additions. See Section&nbsp;<!-- /@w --><a href="#Local-additions">Local additions</a>.

   </ul>

   <p>The <samp><span class="file">doc</span></samp> directory is intended for implementation-independent and
operating system-independent documentation
files. Implementation-dependent files are best stored elsewhere, as
provided for by the implementation and/or TeX administrator (for
example, VMS help files under <samp><span class="file">texmf/vms/help</span></samp>).

   <p>The documentation directories may contain TeX sources, DVI
files, PostScript files, text files, example input files, or any other useful
documentation format(s).

   <p>See Section&nbsp;<!-- /@w --><a href="#Documentation-tree-summary">Documentation tree summary</a> for a summary.

<div class="node">
<p><hr>
<a name="Summary"></a>
Next:&nbsp;<a rel="next" accesskey="n" href="#Unspecified-pieces">Unspecified pieces</a>,
Previous:&nbsp;<a rel="previous" accesskey="p" href="#Top_002dlevel-directories">Top-level directories</a>,
Up:&nbsp;<a rel="up" accesskey="u" href="#Top">Top</a>

</div>

<h2 class="chapter">4 Summary</h2>

<p>A skeleton of a TDS <samp><span class="file">texmf</span></samp> directory tree.  This is not to
imply these are the only entries allowed.  For example, <samp><span class="file">local</span></samp> may
occur at any level.

<pre class="example">       bibtex/           BibTeX input files
         bib/            BibTeX databases
           base/         base distribution (e.g., <samp><span class="file">xampl.bib</span></samp>)
           misc/         single-file databases
         &lt;package&gt;/      name of a package
         bst/            BibTeX style files
           base/         base distribution (e.g., <samp><span class="file">plain.bst</span></samp>, <samp><span class="file">acm.bst</span></samp>)
           misc/         single-file styles
         &lt;package&gt;/      name of a package
       doc/              see Section&nbsp;<!-- /@w --><a href="#Documentation">Documentation</a> and the summary below
       fonts/            font-related files
         &lt;type&gt;/         file type (e.g., <samp><span class="file">pk</span></samp>)
           &lt;mode&gt;/       type of output device (for <samp><span class="file">pk</span></samp> and <samp><span class="file">gf</span></samp> only)
             &lt;supplier&gt;/     name of a font supplier (e.g., <samp><span class="file">public</span></samp>)
               &lt;typeface&gt;/   name of a typeface (e.g., <samp><span class="file">cm</span></samp>)
                 dpi&lt;nnn&gt;/   font resolution (for <samp><span class="file">pk</span></samp> and <samp><span class="file">gf</span></samp> only)
       &lt;implementation&gt;/ TeX implementations, by name (e.g., <samp><span class="file">emtex</span></samp>)
       local/            files created or modified at the local site
       metafont/         Metafont (non-font) input files
         base/           base distribution (e.g., <samp><span class="file">plain.mf</span></samp>)
         misc/           single-file packages (e.g., <samp><span class="file">modes.mf</span></samp>)
         &lt;package&gt;/      name of a package (e.g., <samp><span class="file">mfpic</span></samp>)
       metapost/         MetaPost input and support files
         base/           base distribution (e.g., <samp><span class="file">plain.mp</span></samp>)
         misc/           single-file packages
         &lt;package&gt;/      name of a package
         support/        support files for MetaPost-related utilities
       mft/              <samp><span class="file">MFT</span></samp> inputs (e.g., <samp><span class="file">plain.mft</span></samp>)
       &lt;program&gt;/        TeX-related programs, by name (e.g., <samp><span class="file">dvips</span></samp>)
       source/           program source code by name (e.g., <samp><span class="file">latex</span></samp>, <samp><span class="file">web2c</span></samp>)
       tex/              TeX input files
         &lt;engine&gt;/       name of an engine (e.g., <samp><span class="file">aleph</span></samp>); can also be lower
         &lt;format&gt;/       name of a format (e.g., <samp><span class="file">plain</span></samp>)
           base/         base distribution for format (e.g., <samp><span class="file">plain.tex</span></samp>)
           misc/         single-file packages (e.g., <samp><span class="file">webmac.tex</span></samp>)
           local/        local additions to or local configuration files for <samp><var>format</var></samp>
           &lt;package&gt;/    name of a package (e.g., <samp><span class="file">graphics</span></samp>, <samp><span class="file">mfnfss</span></samp>)
         generic/        format-independent packages
           hyphen/       hyphenation patterns (e.g., <samp><span class="file">hyphen.tex</span></samp>)
           images/       image input files (e.g., Encapsulated PostScript)
           misc/         single-file format-independent packages (e.g., <samp><span class="file">null.tex</span></samp>).
           &lt;package&gt;/    name of a package (e.g., <samp><span class="file">babel</span></samp>)
</pre>
   <ul class="menu">
<li><a accesskey="1" href="#Documentation-tree-summary">Documentation tree summary</a>
</ul>

<div class="node">
<p><hr>
<a name="Documentation-tree-summary"></a>
Up:&nbsp;<a rel="up" accesskey="u" href="#Summary">Summary</a>

</div>

<h3 class="section">4.1 Documentation tree summary</h3>

<p>An example skeleton of a TDS directory tree under
<samp><span class="file">texmf/doc</span></samp>.  This is not to imply these are the only entries
allowed, or that this structure must be followed precisely for the
entries listed.

   <p>As mentioned, the <samp><span class="file">texmf/doc</span></samp> tree may be organized by language, so
that all documentation in French, say, is in a <samp><span class="file">french</span></samp>
subdirectory.  In that case, the example structure here would be in a
given language directory.

<pre class="example">       ams/
         amsfonts/       <samp><span class="file">amsfonts.faq</span></samp>, <samp><span class="file">amfndoc</span></samp>
         amslatex/       <samp><span class="file">amslatex.faq</span></samp>, <samp><span class="file">amsldoc</span></samp>
         amstex/         <samp><span class="file">amsguide</span></samp>, <samp><span class="file">joyerr</span></samp>
       bibtex/           BibTeX
         base/           <samp><span class="file">btxdoc.tex</span></samp>
       fonts/
         fontname/       <cite>Filenames for TeX fonts</cite>
         oldgerm/        <samp><span class="file">corkpapr</span></samp>
       &lt;format&gt;/         name of a TeX format (e.g., <samp><span class="file">generic</span></samp>, <samp><span class="file">latex</span></samp>)
         base/           for the base distribution
         misc/           for contributed single-file package documentation
         &lt;package&gt;/      for <em>package</em>
       general/          across programs, generalities
         errata/         <samp><span class="file">errata</span></samp>, <samp><span class="file">errata[1-8]</span></samp>
         texcomp/        <cite>Components of TeX</cite>
       help/             meta-information
         ctan/           info about CTAN mirror sites
         faq/            FAQs of <samp><span class="file">comp.text.tex</span></samp>, etc.
       info/             GNU Info files, made from Texinfo sources
       latex/            example of <samp><var>format</var></samp>
         base/           <samp><span class="file">ltnews*</span></samp>, <samp><span class="file">*guide</span></samp>, etc.
         graphics/       <samp><span class="file">grfguide</span></samp>
       local/            site-specific documentation
       man/              Unix man pages
       &lt;program&gt;/        TeX-related programs, by name (examples follow)
       metafont/         <samp><span class="file">mfbook.tex</span></samp>, <samp><span class="file">metafont-for-beginners</span></samp>, etc.
       metapost/         <samp><span class="file">mpman</span></samp>, <samp><span class="file">manfig</span></samp>, etc.
       tex/              <samp><span class="file">texbook.tex</span></samp>, <cite>A Gentle Introduction to TeX</cite>, etc.
       web/              <samp><span class="file">webman</span></samp>, <samp><span class="file">cwebman</span></samp>
</pre>
   <div class="node">
<p><hr>
<a name="Unspecified-pieces"></a>
Next:&nbsp;<a rel="next" accesskey="n" href="#Implementation-issues">Implementation issues</a>,
Previous:&nbsp;<a rel="previous" accesskey="p" href="#Summary">Summary</a>,
Up:&nbsp;<a rel="up" accesskey="u" href="#Top">Top</a>

</div>

<h2 class="appendix">Appendix A Unspecified pieces</h2>

<p>The TDS cannot address the following aspects of a functioning
TeX system:

     <ol type=1 start=1>

     <li>The location of executable programs: this is too site-dependent
even to recommend a location, let alone require one. A site may place
executables outside the <samp><span class="file">texmf</span></samp> tree altogether (e.g.,
<samp><span class="file">/usr/local/bin</span></samp>), in a platform-dependent directory within
<samp><span class="file">texmf</span></samp>, or elsewhere.

     <li>Upgrading packages when new releases are made: we could find no
way of introducing version specifiers into <samp><span class="file">texmf</span></samp> that would do more
good than harm, or that would be practical for even a plurality of
installations.

     <li>The location of implementation-specific files (e.g., TeX
<samp><span class="file">.fmt</span></samp> files): by their nature, these must be left to the
implementor or TeX maintainer. See Section&nbsp;<!-- /@w --><a href="#Example-implementation_002dspecific-trees">Example implementation-specific trees</a>.

     <li>Precisely when a package or file should be considered &ldquo;local&rdquo;,
and where such local files are installed.  See Section&nbsp;<!-- /@w --><a href="#Local-additions">Local additions</a> for more discussion.

        </ol>

<ul class="menu">
<li><a accesskey="1" href="#Portable-filenames">Portable filenames</a>
</ul>

<div class="node">
<p><hr>
<a name="Portable-filenames"></a>
Up:&nbsp;<a rel="up" accesskey="u" href="#Unspecified-pieces">Unspecified pieces</a>

</div>

<h3 class="section">A.1 Portable filenames</h3>

<p>The TDS cannot require any particular restriction on filenames in
the tree, since the names of many existing TeX files conform to no
standard scheme. For the benefit of people who wish to make a portable
TeX distribution or installation, however, we outline here the
necessary restrictions. The TDS specifications themselves are
compatible with these.

   <p>ISO-9660 is the only universally acceptable file system format
for CD-ROMs.  A subset thereof meets the stringent limitations of
all operating systems in use today. It specifies the following:

     <ul>
<li>File and directory names, not including any directory path or
extension part, may not exceed eight characters.

     <li>Filenames may have a single extension.  Extensions may not exceed
three characters. Directory names may not have an extension.

     <li>Names and extensions may consist of <em>only</em> the characters
<samp><span class="file">A</span></samp>&ndash;<samp><span class="file">Z</span></samp>, <samp><span class="file">0</span></samp>&ndash;<samp><span class="file">9</span></samp>, and underscore. 
Lowercase letters are excluded.

     <li>A period separates the filename from the extension and is always
present, even if the name or extension is missing (e.g.,
<samp><span class="file">FILENAME.</span></samp> or <samp><span class="file">.EXT</span></samp>).

     <li>A version number, ranging from 1&ndash;32767, is appended to the file
extension, separated by a semicolon (e.g., <samp><span class="file">FILENAME.EXT;1</span></samp>).

     <li>Only eight directory levels are allowed, including the top-level
(mounted) directory (see Section&nbsp;<!-- /@w --><a href="#Rooting-the-tree">Rooting the tree</a>).  Thus, the
deepest valid ISO-9660 path is:
     <pre class="example">          texmf/L2/L3/L4/L5/L6/L7/L8/FOO.BAR;1
          1     2  3  4  5  6  7  8
     </pre>
     <p>The deepest TDS path needs only seven levels:
     <pre class="example">          texmf/fonts/pk/cx/public/cm/dpi300/cmr10.pk
          1     2     3  4  5      6  7
     </pre>
     </ul>

   <p>Some systems display a modified format of ISO-9660 names,
mapping alphabetic characters to lowercase, removing version numbers and
trailing periods, etc.

   <p>Before the December 1996 release, LaTeX used mixed-case names for
font descriptor files.  Fortunately, it never relied on case alone to
distinguish among the files.  Nowadays, it uses only monocase names.

<div class="node">
<p><hr>
<a name="Implementation-issues"></a>
Next:&nbsp;<a rel="next" accesskey="n" href="#Is-there-a-better-way_003f">Is there a better way?</a>,
Previous:&nbsp;<a rel="previous" accesskey="p" href="#Unspecified-pieces">Unspecified pieces</a>,
Up:&nbsp;<a rel="up" accesskey="u" href="#Top">Top</a>

</div>

<h2 class="appendix">Appendix B Implementation issues</h2>

<p>We believe that the TDS can bring a great deal of order to the
current anarchic state of many TeX installations.  In addition, by
providing a common frame of reference, it will ease the burden of
documenting administrative tasks.  Finally, it is a necessary part of
any reasonable system of true &ldquo;drop-in&rdquo; distribution packages for
TeX.

<ul class="menu">
<li><a accesskey="1" href="#Adoption-of-the-TDS">Adoption of the TDS</a>
<li><a accesskey="2" href="#More-on-subdirectory-searching">More on subdirectory searching</a>
<li><a accesskey="3" href="#Example-implementation_002dspecific-trees">Example implementation-specific trees</a>
</ul>

<div class="node">
<p><hr>
<a name="Adoption-of-the-TDS"></a>
Next:&nbsp;<a rel="next" accesskey="n" href="#More-on-subdirectory-searching">More on subdirectory searching</a>,
Up:&nbsp;<a rel="up" accesskey="u" href="#Implementation-issues">Implementation issues</a>

</div>

<h3 class="section">B.1 Adoption of the TDS</h3>

<p>[This section is retained for historical purposes; the TDS
is now quite firmly entrenched in most TeX distributions.]

   <p>We recognize that adoption of the TDS will not be immediate or
universal.  Most TeX administrators will not be inclined to make the
final switch until:

     <ul>
<li>Clear and demonstrable benefits can be shown for the TDS. 
<li>TDS-compliant versions of all key programs are available
in ported, well-tested forms. 
<li>A &ldquo;settling&rdquo; period has taken place, to flush out problems.  The
public release of the first draft of this document was the first step in
this process. 
</ul>

   <p>Consequently, most of the first trials of the TDS will be made by
members of the TDS committee and/or developers of TeX-related
software.  This has already taken place during the course of our
deliberations (see Appendix&nbsp;<!-- /@w --><a href="#Related-references">Related references</a> for a sample
tree available electronically).  They will certainly result in the
production of a substantial number of TDS-compliant packages. 
Indeed, the teTeX and TeX Live
distributions are TDS-compliant and in use now at many sites.

   <p>Once installable forms of key TDS-compliant packages are more
widespread, some TeX administrators will set up TDS-compliant
trees, possibly in parallel to existing production directories.  This
testing will likely flush out problems that were not obvious in the
confined settings of the developers' sites; for example, it should help
to resolve system and package dependencies, package interdependencies, and
other details not addressed by this TDS version.

   <p>After most of the dust has settled, hopefully even conservative TeX
administrators will begin to adopt the TDS.  Eventually, most
TeX sites will have adopted the common structure, and most packages
will be readily available in TDS-compliant form.

   <p>We believe that this process will occur relatively quickly.  The
TDS committee spans a wide range of interests in the TeX
community.  Consequently, we believe that most of the key issues
involved in defining a workable TDS definition have been covered,
often in detail.  TeX developers have been consulted about
implementation issues, and have been trying out the TDS
arrangement.  Thus, we hope for few surprises as implementations mature.

   <p>Finally, there are several (current or prospective) publishers of TeX
CD-ROMs.  These publishers are highly motivated to work out
details of TDS implementation, and their products will provide
inexpensive and convenient ways for experimentally-minded TeX
administrators to experiment with the TDS.

<div class="node">
<p><hr>
<a name="More-on-subdirectory-searching"></a>
Next:&nbsp;<a rel="next" accesskey="n" href="#Example-implementation_002dspecific-trees">Example implementation-specific trees</a>,
Previous:&nbsp;<a rel="previous" accesskey="p" href="#Adoption-of-the-TDS">Adoption of the TDS</a>,
Up:&nbsp;<a rel="up" accesskey="u" href="#Implementation-issues">Implementation issues</a>

</div>

<h3 class="section">B.2 More on subdirectory searching</h3>

<p>Recursive subdirectory searching is the ability to specify a search not
only of a specified directory <samp><var>d</var></samp>, but recursively of all
directories below <samp><var>d</var></samp>.

   <p>Since the TDS specifies precise locations for most files, with no
extra levels of subdirectories allowed, true recursive searching is not
actually required for a TDS-compliant implementation. We do,
however, strongly recommend recursive searching as the most
user-friendly and natural approach to the problem, rather than
convoluted methods to specify paths without recursion.

   <p>This feature is already supported by many implementations of TeX and
companion utilities, for example DECUS TeX for VMS,
Dvips(k), emTeX (and its drivers),
PubliC TeX, Web2C, Xdvi(k),
and Y&amp;YTeX.  The Kpathsea library is a reusable
implementation of subdirectory searching for TeX, used in a number of
the above programs.

   <p>Even if your TeX implementation does not directly support
subdirectory searching, you may find it useful to adopt the structure if
you do not use many fonts or packages. For instance, if you only use
Computer Modern and AMS fonts, it would be feasible to store them
in the TDS layout and list the directories individually in
configuration files or environment variables.

   <p>The TWG recognizes that subdirectory searching places an extra
burden on the system and may be the source of performance bottlenecks,
particularly on slower machines.  Nevertheless, we feel that
subdirectory searching is imperative for a well-organized TDS,
for the reasons stated in Section&nbsp;<!-- /@w --><a href="#Subdirectory-searching">Subdirectory searching</a>. 
Implementors are encouraged to provide enhancements to the basic
principle of subdirectory searching to avoid performance problems, e.g.,
the use of a filename cache (this can be as simple as a recursive
directory listing) that is consulted before disk searching begins.  If a
match is found in the database, subdirectory searching is not required,
and performance is thus independent of the number of subdirectories
present on the system.

   <p>Different implementations specify subdirectory searching differently. 
In the interest of typographic clarity, the examples here do not use the
<samp><var>replaceable</var></samp> font.

     <ul>
<li>Dvips:
via a separate
<samp><span class="file">TEXFONTS_SUBDIR</span></samp> environment variable.

     <li>emTeX:
<samp><span class="file">t:\subdir!!</span></samp>; <samp><span class="file">t:\subdir!</span></samp> for
a single level of searching.

     <li>Kpathsea:
<samp><span class="file">texmf/subdir//</span></samp>

     <li>VMS:
<samp><span class="file">texmf:[subdir...]</span></samp>

     <li>Xdvi (patchlevel 20):
<samp><span class="file">texmf/subdir/**</span></samp>;
<samp><span class="file">texmf/subdir/*</span></samp> for a single level of searching.  Version 20.50
and above support the <samp><span class="file">//</span></samp> notation.

     <li>Y&amp;Y TeX:
<samp><span class="file">t:/subdir//</span></samp> or
<samp><span class="file">t:\subdir\\</span></samp>.

   </ul>

<div class="node">
<p><hr>
<a name="Example-implementation-specific-trees"></a>
<a name="Example-implementation_002dspecific-trees"></a>
Previous:&nbsp;<a rel="previous" accesskey="p" href="#More-on-subdirectory-searching">More on subdirectory searching</a>,
Up:&nbsp;<a rel="up" accesskey="u" href="#Implementation-issues">Implementation issues</a>

</div>

<h3 class="section">B.3 Example implementation-specific trees</h3>

<p>The TDS cannot specify a precise location for
implementation-specific files, such as <samp><span class="file">texmf/ini</span></samp>, because a site
may have multiple TeX implementations.

   <p>Nevertheless, for informative purposes, we provide here the default
locations for some implementations. Please contact us with additions or
corrections. These paths are not definitive, may not match anything at
your site, and may change without warning.

   <p>We recommend all implementations have default search paths that start
with the current directory (e.g., <samp><span class="file">.</span></samp>).  Allowing users to
include the parent directory (e.g., <samp><span class="file">..</span></samp>) is also helpful.

<ul class="menu">
<li><a accesskey="1" href="#AmiWeb2c-2_002e0">AmiWeb2c 2.0</a>
<li><a accesskey="2" href="#Public-DECUS-TeX">Public DECUS TeX</a>
<li><a accesskey="3" href="#Web2c-7">Web2c 7</a>
</ul>

<div class="node">
<p><hr>
<a name="AmiWeb2c-2.0"></a>
<a name="AmiWeb2c-2_002e0"></a>
Next:&nbsp;<a rel="next" accesskey="n" href="#Public-DECUS-TeX">Public DECUS TeX</a>,
Up:&nbsp;<a rel="up" accesskey="u" href="#Example-implementation_002dspecific-trees">Example implementation-specific trees</a>

</div>

<h4 class="subsection">B.3.1 AmiWeb2c 2.0</h4>

<p>(Email <a href="mailto:scherer@physik.rwth-aachen.de">scherer@physik.rwth-aachen.de</a> to contact the maintainer
of this implementation.)

   <p>AmiWeb2c 2 is compatible with Web2c 7 to the greatest possible
extent, so only the very few differences are described in this
section.  Detailed information about the basic concepts is given in
the section for Web2c 7 below.

   <p>Thanks to the <samp><span class="file">SELFAUTO</span></samp> mechanism of Kpathsea 3.0 no specific
location for the installation of AmiWeb2c is required as long as the
general structure of the distribution is preserved.

   <p>In addition to Kpathsea's <samp><span class="file">//</span></samp> notation recursive path search may
also be started by <samp><var>DEVICE</var><span class="file">:/</span></samp>, e.g., <samp><span class="file">TeXMF:/</span></samp>
will scan this specific device completely.

   <p>Binaries coming with the AmiWeb2c distribution are installed in the
directory <samp><span class="file">bin/amiweb2c/</span></samp> outside the common TDS tree
<samp><span class="file">share/texmf/</span></samp>.  In addition to the set of AmiWeb2c binaries
you will find two subdirectories <samp><span class="file">local/</span></samp> and <samp><span class="file">pastex/</span></samp>
with auxiliary programs.

   <p>A stripped version of the PasTeX system (used by kind permission of
Georg He&szlig;mann) is coming with AmiWeb2c, pre-installed in its own
<samp><span class="file">share/texmf/amiweb2c/pastex/</span></samp> directory.  If you want to use
PasTeX you have to <samp><span class="file">assign</span></samp> the name <samp><span class="file">TeX:</span></samp> to this place.

   <p>Documentation files in AmigaGuide format should be stored at
<samp><span class="file">doc/guide/</span></samp> similar to <samp><span class="file">doc/info/</span></samp>.

<div class="node">
<p><hr>
<a name="Public-DECUS-TeX"></a>
Next:&nbsp;<a rel="next" accesskey="n" href="#Web2c-7">Web2c 7</a>,
Previous:&nbsp;<a rel="previous" accesskey="p" href="#AmiWeb2c-2_002e0">AmiWeb2c 2.0</a>,
Up:&nbsp;<a rel="up" accesskey="u" href="#Example-implementation_002dspecific-trees">Example implementation-specific trees</a>

</div>

<h4 class="subsection">B.3.2 Public DECUS TeX</h4>

<p>If another VMS implementation besides Public DECUS TeX
appears, the top level implementation directory name will be modified to
something more specific (e.g., <samp><span class="file">vms_decus</span></samp>).

<pre class="example">       texmf/
         vms/            VMS implementation specific files
           exe/          end-user commands
             common/     command procedures, command definition files, etc.
             axp/        binary executables for Alpha AXP
             vax/        binary executables for VAX
           formats/      pool files, formats, bases
           help/         VMS help library, and miscellaneous help sources
           mgr/          command procedures, programs, docs, etc., for system management
</pre>
   <div class="node">
<p><hr>
<a name="Web2c-7"></a>
Previous:&nbsp;<a rel="previous" accesskey="p" href="#Public-DECUS-TeX">Public DECUS TeX</a>,
Up:&nbsp;<a rel="up" accesskey="u" href="#Example-implementation_002dspecific-trees">Example implementation-specific trees</a>

</div>

<h4 class="subsection">B.3.3 Web2c 7</h4>

<p>All implementation-dependent TeX system files (<samp><span class="file">.pool</span></samp>,
<samp><span class="file">.fmt</span></samp>, <samp><span class="file">.base</span></samp>, <samp><span class="file">.mem</span></samp>) are stored by default directly
in <samp><span class="file">texmf/web2c</span></samp>.  The configuration file <samp><span class="file">texmf.cnf</span></samp> and
various subsidiary <samp><span class="file">MakeTeX...</span></samp> scripts used as subroutines are
also stored there.

   <p>Non-TeX specific files are stored following the GNU coding
standards.  Given a root directory <samp><var>prefix</var></samp>
(<samp><span class="file">/usr/local</span></samp> by default), we have default locations as follows:

<pre class="example">       &lt;prefix&gt;/         installation root (<samp><span class="file">/usr/local</span></samp> by default)
         bin/            executables
         man/            man pages
         info/           info files
         lib/            libraries (<samp><span class="file">libkpathsea.*</span></samp>)
         share/          architecture-independent files
           texmf/        TDS root
             web2c/      implementation-dependent files (<samp><span class="file">.pool</span></samp>, <samp><span class="file">.fmt</span></samp>, <samp><span class="file">texmf.cnf</span></samp>, etc.)
</pre>
   <p>See <a href="http://www.gnu.org/prep/standards_toc.html">http://www.gnu.org/prep/standards_toc.html</a> for the
rationale behind and descriptions of this arrangement. A site may of
course override these defaults; for example, it may put everything under
a single directory such as <samp><span class="file">/usr/local/texmf</span></samp>.

<div class="node">
<p><hr>
<a name="Is-there-a-better-way%3f"></a>
<a name="Is-there-a-better-way_003f"></a>
Next:&nbsp;<a rel="next" accesskey="n" href="#Related-references">Related references</a>,
Previous:&nbsp;<a rel="previous" accesskey="p" href="#Implementation-issues">Implementation issues</a>,
Up:&nbsp;<a rel="up" accesskey="u" href="#Top">Top</a>

</div>

<h2 class="appendix">Appendix C Is there a better way?</h2>

<p>Defining the TDS required many compromises.  Both the overall
structure and the details of the individual directories were arrived at
by finding common ground among many opinions.  The driving forces were
feasibility (in terms of what could technically be done and what could
reasonably be expected from developers) and regularity (files grouped
together in an arrangement that &ldquo;made sense&rdquo;).

   <p>Some interesting ideas could not be applied due to implementations
lacking the necessary support:

     <ul>
<li>Path searching control at the TeX level. If documents could
restrict subdirectory searching to a subdirectory via some portable
syntax in file names, restrictions on uniqueness of filenames could be
relaxed considerably (with the cooperation of the formats), and the
TeX search path would not need to depend on the format.

     <li>Multiple logical <samp><span class="file">texmf</span></samp> trees. For example, a site might have
one (read-only) location for stable files, and a different (writable)
location for dynamically-created fonts or other files. It would be
reasonable for two such trees to be logically merged when searching. 
See Michael Downes' article in the references for how this can work in
practice with Web2C.

   </ul>

<ul class="menu">
<li><a accesskey="1" href="#Macro-structure">Macro structure</a>
<li><a accesskey="2" href="#Font-structure">Font structure</a>
<li><a accesskey="3" href="#Documentation-structure">Documentation structure</a>
</ul>

<div class="node">
<p><hr>
<a name="Macro-structure"></a>
Next:&nbsp;<a rel="next" accesskey="n" href="#Font-structure">Font structure</a>,
Up:&nbsp;<a rel="up" accesskey="u" href="#Is-there-a-better-way_003f">Is there a better way?</a>

</div>

<h3 class="section">C.1 Macro structure</h3>

<p>The TWG settled on the
<samp><var>format</var><span class="file">/</span><var>package</var></samp> arrangement after long
discussion about how best to arrange the files.

   <p>The primary alternative to this arrangement was a scheme which reversed
the order of these directories:
<samp><var>package</var><span class="file">/</span><var>format</var></samp>.  This reversed
arrangement has a strong appeal: it keeps all of the files related to a
particular package in a single place.  The arrangement actually adopted
tends to spread files out into two or three places (macros,
documentation, and fonts, for example, are spread into different
sections of the tree right at the top level).

   <p>Nevertheless, the <samp><var>format</var><span class="file">/</span><var>package</var></samp>
structure won for a couple of reasons:

     <ul>
<li>It is closer to current practice; in fact, several members of the
TWG have already implemented the TDS hierarchy.  The
alternative is not in use at any known site, and the TWG felt it
wrong to mandate something with which there is no practical experience.

     <li>The alternative arrangement increases the number of top-level
directories, so the files that must be found using subdirectory
searching are spread out in a wide, shallow tree.  This could have a
profound impact on the efficiency of subdirectory searching.

   </ul>

<div class="node">
<p><hr>
<a name="Font-structure"></a>
Next:&nbsp;<a rel="next" accesskey="n" href="#Documentation-structure">Documentation structure</a>,
Previous:&nbsp;<a rel="previous" accesskey="p" href="#Macro-structure">Macro structure</a>,
Up:&nbsp;<a rel="up" accesskey="u" href="#Is-there-a-better-way_003f">Is there a better way?</a>

</div>

<h3 class="section">C.2 Font structure</h3>

<p>The TWG struggled more with the font directory structure than
anything else. This is not surprising; the need to use the proliferation
of PostScript fonts with TeX is what made the previous arrangement
with all files in a single directory untenable, and therefore what
initiated the TDS effort.

<ul class="menu">
<li><a accesskey="1" href="#Font-file-type-location">Font file type location</a>
<li><a accesskey="2" href="#Mode-and-resolution-location">Mode and resolution location</a>
<li><a accesskey="3" href="#Modeless-bitmaps">Modeless bitmaps</a>
</ul>

<div class="node">
<p><hr>
<a name="Font-file-type-location"></a>
Next:&nbsp;<a rel="next" accesskey="n" href="#Mode-and-resolution-location">Mode and resolution location</a>,
Up:&nbsp;<a rel="up" accesskey="u" href="#Font-structure">Font structure</a>

</div>

<h4 class="subsection">C.2.1 Font file type location</h4>

<p>We considered the supplier-first arrangement in use at many sites:

<pre class="example">     texmf/fonts/<var>supplier</var>/<var>typeface</var>/<var>type</var>/
</pre>
   <p>This improves the maintainability of the font tree, since all files
comprising a given typeface are in one place, but unless all the
programs that search this tree employ some form of caching, there are
serious performance concerns.  For example, in order to find a
<samp><span class="file">TFM</span></samp> file, the simplest implementation would require TeX to
search through all the directories that contain PK files in all
modes and at all resolutions.

   <p>In the end, a poll of developers revealed considerable resistance to
implementing sufficient caching mechanisms, so this arrangement was
abandoned.  The TDS arrangement allows the search tree to be
restricted to the correct type of file, at least.  Concerns about
efficiency remain, but there seems to be no more we can do without
abandoning subdirectory searching entirely.

   <p>We also considered segregating all font-related files strictly by file
type, so that Metafont sources would be in a directory
<samp><span class="file">texmf/fonts/mf</span></samp>, property list files in <samp><span class="file">texmf/fonts/pl</span></samp>, the
various forms of Type&nbsp;<!-- /@w -->1 fonts separated, and so on. Although more
blindly consistent, we felt that the drawback of more complicated path
constructions outweighed this. The TDS merges file types
(<samp><span class="file">mf</span></samp> and <samp><span class="file">pl</span></samp> under <samp><span class="file">source</span></samp>, <samp><span class="file">pfa</span></samp> and <samp><span class="file">pfb</span></samp>
and <samp><span class="file">gsf</span></samp> under <samp><span class="file">type1</span></samp>) where we felt this was beneficial.

<div class="node">
<p><hr>
<a name="Mode-and-resolution-location"></a>
Next:&nbsp;<a rel="next" accesskey="n" href="#Modeless-bitmaps">Modeless bitmaps</a>,
Previous:&nbsp;<a rel="previous" accesskey="p" href="#Font-file-type-location">Font file type location</a>,
Up:&nbsp;<a rel="up" accesskey="u" href="#Font-structure">Font structure</a>

</div>

<h4 class="subsection">C.2.2 Mode and resolution location</h4>

<p>We considered having the <samp><span class="file">mode</span></samp> at the bottom of the font tree:
<pre class="example">     texmf/fonts/pk/<var>supplier</var>/<var>typeface</var>/<var>mode</var>/<var>dpi</var>/
</pre>
   <p>In this case, however, it is difficult to limit subdirectory searching
to the mode required for a particular device.

   <p>We then considered moving the <samp><span class="file">dpi</span><var>nnn</var></samp> up to below
the mode:
<pre class="example">     texmf/fonts/pk/<var>mode</var>/<var>dpi</var>/<var>supplier</var>/<var>typeface</var>/
</pre>
   <p>But then it is not feasible to omit the <samp><span class="file">dpi</span><var>nnn</var></samp>
level altogether on systems which can and do choose to use long
filenames.

<div class="node">
<p><hr>
<a name="Modeless-bitmaps"></a>
Previous:&nbsp;<a rel="previous" accesskey="p" href="#Mode-and-resolution-location">Mode and resolution location</a>,
Up:&nbsp;<a rel="up" accesskey="u" href="#Font-structure">Font structure</a>

</div>

<h4 class="subsection">C.2.3 Modeless bitmaps</h4>

<p>The TDS specifies using a single directory <samp><span class="file">modeless/</span></samp> as
the mode name for those utilities which generate bitmaps, e.g.,
<samp><span class="file">texmf/fonts/modeless/times/</span></samp>.  This has the considerable advantage
of not requiring each such directory name to be listed in a search path.

   <p>An alternative was to use the utility name below which all such
directories could be gathered.  That has the advantage of separating,
say, <samp><span class="file">gsftopk</span></samp>-generated bitmaps from <samp><span class="file">ps2pk</span></samp>-generated ones. 
However, we decided this was not necessary; most sites will use only one
program for the purpose.  Also, PK and GF fonts generally
identify their creator in the font comment following the <samp><span class="file">PK_ID</span></samp>
byte.

   <p>We are making an implicit assumption that Metafont is the only program
producing mode-dependent bitmaps. If this becomes false we could add an
abbreviation for the program to mode names, as in <samp><span class="file">mfcx</span></samp> vs. 
<samp><span class="file">xyzcx</span></samp> for a hypothetical program Xyz, or we could
at that time add an additional program name level uniformly to the tree. 
It seemed more important to concisely represent the current situation
than to worry about hypothetical possibilities that may never&nbsp;<!-- /@w -->happen.

<div class="node">
<p><hr>
<a name="Documentation-structure"></a>
Previous:&nbsp;<a rel="previous" accesskey="p" href="#Font-structure">Font structure</a>,
Up:&nbsp;<a rel="up" accesskey="u" href="#Is-there-a-better-way_003f">Is there a better way?</a>

</div>

<h3 class="section">C.3 Documentation structure</h3>

<p>We considered placing additional documentation files in the same
directory as the source files for the packages, but we felt that users
should be able to find documentation separately from sources, since most
users have no interest in sources.

   <p>We hope that a separate, but parallel, structure for documentation would
(1)&nbsp;<!-- /@w -->keep the documentation together and (2)&nbsp;<!-- /@w -->make it as straightforward
as possible for users to find the particular documentation they were
after.

<div class="node">
<p><hr>
<a name="Related-references"></a>
Next:&nbsp;<a rel="next" accesskey="n" href="#Contributors">Contributors</a>,
Previous:&nbsp;<a rel="previous" accesskey="p" href="#Is-there-a-better-way_003f">Is there a better way?</a>,
Up:&nbsp;<a rel="up" accesskey="u" href="#Top">Top</a>

</div>

<h2 class="appendix">Appendix D Related references</h2>

<p>This appendix gives pointers to related files and other documents.  For
CTAN references, we use <samp><span class="file">http://www.ctan.org</span></samp> as the
top-level domain only to make the links be live in this document.  See
<a href="http://www.ctan.org/tex-archive/CTAN.sites">http://www.ctan.org/tex-archive/CTAN.sites</a> for a complete list of
CTAN sites; there are mirrors worldwide.

     <ul>
<li>This document, in many formats (tex, dvi, info, pdf):<br>
<a href="http://tug.org/tds/">http://tug.org/tds/</a>

     <li>The TDS mailing list archives:<br>
<a href="http://tug.org/mail-archives/twg-tds/">http://tug.org/mail-archives/twg-tds/</a>

     <li>The level&nbsp;<!-- /@w -->0 DVI driver standard:<br>
<a href="http://www.ctan.org/tex-archive/dviware/driv-standard/level-0/">http://www.ctan.org/tex-archive/dviware/driv-standard/level-0/</a>

     <li><cite>Filenames for TeX fonts</cite>, with lists of recommended
supplier and typeface names:<br>
<a href="http://tug.org/fontname/">http://tug.org/fontname/</a>

     <li>ISO-9660 CD-ROM file system standard:<br>
<a href="http://www.iso.ch/cate/cat.html">http://www.iso.ch/cate/cat.html</a>

     <li><cite>Components of TeX</cite>, a paper by Joachim
Schrod:<br>
<a href="http://www.ctan.org/tex-archive/documentation/components-of-TeX/">http://www.ctan.org/tex-archive/documentation/components-of-TeX/</a>

     <li><cite>Managing Multiple TDS trees</cite>, an article by Michael
Downes:<br>
<a href="http://tug.org/TUGboat/Articles/tb22-3/tb72downes.pdf">http://tug.org/TUGboat/Articles/tb22-3/tb72downes.pdf</a>

     <li>A complete set of Metafont modes:<br>
<a href="http://www.ctan.org/tex-archive/fonts/modes/modes.mf">http://www.ctan.org/tex-archive/fonts/modes/modes.mf</a>

     <li>A large collection of BibTeX databases and styles:<br>
<a href="ftp://ftp.math.utah.edu/pub/tex/bib/">ftp://ftp.math.utah.edu/pub/tex/bib/</a>

   </ul>

<div class="node">
<p><hr>
<a name="Contributors"></a>
Previous:&nbsp;<a rel="previous" accesskey="p" href="#Related-references">Related references</a>,
Up:&nbsp;<a rel="up" accesskey="u" href="#Top">Top</a>

</div>

<h2 class="appendix">Appendix E Contributors</h2>

<p>The TWG has had no physical meetings; electronic mail was the
communication medium.

   <p>Sebastian Rahtz is the TeX Users Group Technical Council liaison. 
Norman Walsh was the original committee chair.  Karl Berry is the
current editor.

   <p>The list of contributors has grown too large to fairly include, as some
would surely be inadvertently omitted.  Please consider the archives of
the <a href="mailto:tds@tug.org">tds@tug.org</a> and <a href="mailto:tex-live@tug.org">tex-live@tug.org</a> mailing lists as
the record of contributions.

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tex-common 6.04 / usr / share / doc / tex-common / tds.html
