Copyright © 1994, 1995, 1996, 1997, 1998, 1999, 2003 TeX Users Group.
Permission to use, copy, and distribute this document without modification for any purpose and without fee is hereby granted, provided that this notice appears in all copies. It is provided "as is" without expressed or implied warranty.
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.
This document is available on any CTAN host (Appendix Related references has a complete reference). Please send questions or suggestions by email to tds@tug.org. We welcome all comments.
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 "right" way to install it. This has resulted in many sites having different installed arrangements.
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.
This document is intended both for the TeX system administrator at a site and for people preparing TeX distributions--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 Related references.
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.
At first glance, it may seem that the Comprehensive TeX Archive Network (CTAN) archives fulfill 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.
In fact, the roles of the TDS and CTAN are frequently in conflict, as you will see elsewhere in this document. 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.
In this document, / is used to separate filename components;
for example, texmf/fonts. This is the Unix convention but the
ideas are in no way Unix-specific.
In this document, "TeX" generally means the TeX system, including METAFONT, DVI drivers, utilities, etc., not just the TeX program itself.
The word "package" in this document has its usual meaning: a set of related files distributed, installed, and maintained as a unit. This is not a LaTeX2e package, which is a style file supplementing a document class.
We use the following typographic conventions:
literal
Literal text such as filename is
typeset in typewriter type.
This section describes common properties throughout the TDS tree.
Many TeX installations store large numbers of related files in single
directories, for example, all TFM files and/or all TeX
input files.
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.
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.
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.
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.
The TDS does not specify a syntax for specifying recursive searching, but we encourage implementors to provide interoperability (see Section More on subdirectory searching).
In this document, we shall designate the root TDS directory by
texmf (for "TeX and METAFONT"). 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 T:.
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, /usr/local/share, /usr/local,
/usr/local/lib, and /opt are common choices.
The name texmf 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.
A site may choose to have more than one TDS hierarchy installed (for example, when installing an upgrade). This is perfectly legitimate.
The TDS cannot specify precisely when a package is or is not a "local addition". Each site must determine this according to its own conventions. At the two extremes, one site might wish to consider "nonlocal" all files not acquired as part of the installed TeX distribution; another site might consider "local" only those files that were actually developed at the local site and not distributed elsewhere.
We recognize two common methods for local additions to a distributed
texmf tree. Both have their place; in fact, some sites employ
both simultaneously:
/usr/local/umbtex at the University of
Massachusetts at Boston. This is another example of the multiple
texmf hierarchies mentioned in the previous section.
local at any appropriate level, for
example, in the local for this
purpose.
We recommend using local for site-adapted configuration files,
such as language.dat for the Babel package or graphics.cfg
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.
One common case of local additions is dynamically generated files, e.g.,
PK fonts by the MakeTeXPK script originated by
Dvips. A site may store the generated files directly in
any of:
texmf/fonts/tmp);
/var, for example /var/spool/fonts).
No one solution will be appropriate for all sites.
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:
texmf/tex and texmf/tex/generic, but not
within all of texmf/tex; i.e., different TeX formats may have
files by the same name. (Section Macros discusses this
further.) Thus, no single format-independent path specification, such
as a recursive search beginning at texmf/tex specifying no other
directories, suffices. So implementations must provide format-dependent
path specifications, for example via wrapper scripts or configuration
files.
cmr10.pk),
as discussed in Section Valid font bitmaps. Implementations
must distinguish these files by mode and resolution.
All implementations we know of already have these capabilities.
One place where duplicate names are likely to occur is not an exception:
texmf/fonts. In practice, this is a problem with
some variants of Computer Modern which contain slightly modified files
named punct.mf, romanl.mf, and so on. We believe the only
feasible solution is to rename the derivative files to be
unique.
The directories under the texmf root identify the major components of
a TeX system (see Section Summary for a summary). A site
may omit any unneeded directories.
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 texmf 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.
The top-level directories specified by the TDS are:
tex
for TeX files (Section Macros).
fonts
for font-related files (Section Fonts).
metafont
for METAFONT files which are not fonts (Section Non-font METAFONT files).
metapost
for MetaPost files (Section MetaPost).
bibtex
for BibTeX files (Section BibTeX).
doc
for user documentation (Section Documentation).
source
for sources. This includes both traditional
program sources (for example, Web2C sources go in
texmf/source/web2c) and, e.g., LaTeX dtx sources (which
go in texmf/source/latex). The TDS leaves unspecified any
structure under source.
source 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, plain.tex does not belong under texmf/source,
even though it is a "source file" in the sense of not being derived
from another file. (It goes in texmf/tex/plain/base, as explained
in Section Macros).
emtex, web2c), to be used for whatever purpose deemed
suitable by the implementor or TeX administrator. Files that cannot
be shared between implementations, such as pool files (tex.pool)
and memory dump files (plain.fmt) go here, in addition to
implementation-wide configuration files. See Section Example implementation-specific trees for examples of real
etex, pdftex, omega) that are
extensions of TeX, METAFONT, or any standard program. See
Section Extensions.
mft, dvips). In fact, the tex, metafont,
metapost, bibtex, and 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 \dump-able package):
texmf/tex/format/package/
amstex,
latex, plain, texinfo).
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
format 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.
The TDS reserves the following format names:
generic,
for input files that are useful across a wide
range of formats (examples: null.tex, path.sty).
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
texmf/tex/plain), e.g., testfont.tex and plain.tex
itself.
local,
for local additions. See Section Local additions.
Thus, for almost every format, it is necessary to search at least the
format directory and then the generic directory (in
that order). Other directories may need to be searched as well,
depending on the format. When using AMS-TeX, for example, the
amstex, plain, and generic directories should be
searched, because AMS-TeX is compatible with Plain.
babel, texdraw).
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
format directory, instead of
format/base. For example, Texinfo goes in
texmf/tex/texinfo/texinfo.tex, not
texmf/tex/texinfo/base/texinfo.tex.
The TDS reserves the following package names:
base,
for the base distribution of each format,
including files used by INITEX when dumping format files. For
example, in the standard LaTeX distribution, the ltx files
created during the build process shall be stored in the base
directory.
hyphen,
for hyphenation patterns, including the original
American English hyphen.tex. These are typically used only by
INITEX. In most situations, this directory need exist only under the
generic format.
images,
for image input files, such as Encapsulated
PostScript figures. Although it is somewhat non-intuitive for these to
be under a directory named tex, 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 generic format.
local,
for local additions and configuration files. See
Section Local additions.
misc,
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 misc.
Font files shall be 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.
texmf/fonts/type/supplier/typeface/
texmf/fonts/enc,map/syntax/
afm,
for Adobe font metrics.
gf,
for generic font bitmap files.
pk,
for packed bitmap files.
source,
for font sources (METAFONT files, property lists, etc.).
tfm,
for TeX font metric files.
type1,
for Type 1 fonts (in any format).
vf,
for virtual fonts.
The TDS also reserves the names enc and map for font
encoding and font mapping files, respectively. For these files,
segregation is by syntax rather than supplier. At present, there is
only one syntax for each, named dvips since that's the program
that originated them. For details of the Dvips syntax for encoding map
files, see the `psfonts.map' section in the Dvips manual. The Fontname
collection has a number of instances of both file types.
As usual, a site may omit any of these directories that are unnecessary.
gf is a particularly likely candidate for omission.
adobe, ams, public). The TDS
reserves the following ams,
for the American Mathematical Society's AMS-fonts
collection.
local,
for local additions. See Section Local additions.
public,
for freely redistributable fonts where the supplier
neither (1) requested their own directory (e.g., ams), nor
(2) also made proprietary fonts (e.g., adobe). It does not
contain all extant freely distributable fonts, nor are all files therein
necessarily strictly public domain.
tmp,
for dynamically-generated fonts, as is traditional on
some systems. It may be omitted if unnecessary, as usual.
cm, euler, times). The TDS
reserves the following cm (within public),
for the 75 fonts defined in
Computers and Typesetting, Volume E.
latex (within public),
for those fonts distributed
with LaTeX in the base distribution.
local,
for local additions. See Section Local additions.
Some concrete examples:
texmf/fonts/source/public/pandora/pnr10.mf
texmf/fonts/tfm/public/cm/cmr10.tfm
texmf/fonts/type1/adobe/utopia/putr.pfa
For complete supplier and typeface name lists, consult Filenames for TeX fonts (see Appendix Related references).
Font bitmap files require two characteristics in addition to the above to be uniquely identifiable: (1) the type of device (i.e., mode) for which the font was created; (2) the resolution of the bitmap.
Following common practice, the TDS segregates fonts with
different device types into separate directories. See modes.mf
in Appendix Related references for recommended mode names.
Some printers operate at more than one resolution (e.g., at 300dpi and 600dpi), 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.
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., cmr10.300pk). On systems which do not support
long filenames, fonts are generally segregated into directories by
resolution (e.g., dpi300/cmr10.pk).
Because the TDS cannot require long filenames, we must use the
latter scheme for naming fonts. So we have two more subdirectory
levels under pk and gf:
texmf/fonts/pk/mode/supplier/typeface/dpinnn/
texmf/fonts/gf/mode/supplier/typeface/dpinnn/
cx, ljfour, modeless). 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 modeless. The dpinnndpi300, dpi329). dpi 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.
The integer nnn is to be calculated as if using METAFONT
arithmetic and then rounded; i.e., it is the integer METAFONT uses in its
output gf filename. We recognize small differences in the
resolution are a common cause of frustration among users, however, and
recommend implementors follow the level 0 DVI driver standard
(see Appendix Related references) in bitmap font searches by
allowing a fuzz of +-0.2% (with a minimum of 1) in the
dpi.
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 .fli files), provided that the basic scheme is also
supported.
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,
cmr10.pk will be the filename for Computer Modern Roman 10pt at
5-10 magnifications for 2-3 modes. (Section Duplicate filenames discusses duplicate filenames in general.)
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.
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) modes.mf (see Appendix Related references), the required information is already in your PK
files. If not, a simple addition based on the code found in
modes.mf can be made to your local modes file and the PK
files rebuilt.
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:
texmf/metafont/package/
package is the name of a
METAFONT package (for example, mfpic).
The TDS reserves the following package names:
base,
for the standard METAFONT macro files as described in
The METAFONTbook, such as plain.mf and expr.mf.
local,
for local additions. See Section Local additions.
misc,
for METAFONT packages consisting of only a single file
(for example, modes.mf). An administrator or package maintainer
may create directories for single-file packages at their discretion,
instead of using misc.
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.
MetaPost input files and the support files for MetaPost-related utilities shall be stored in:
texmf/metapost/package/
package 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.
The TDS reserves the following package names:
base,
for the standard MetaPost macro files, such as
plain.mp, mfplain.mp, boxes.mp, and
graph.mp. This includes files used by INIMP when dumping mem
files containing preloaded macro definitions.
local,
for local additions. See Section Local additions.
misc,
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 misc.
support,
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.
BibTeX-related files shall be stored in:
texmf/bibtex/bib/package/
texmf/bibtex/bst/package/
The bib directory is for BibTeX database (.bib) files,
the bst directory for style (.bst) files.
package is the name of a BibTeX package. The
TDS reserves the following package names (the same
names are reserved under both bib and bst):
base,
for the standard BibTeX databases and styles, such
as xampl.bib, plain.bst.
local,
for local additions. See Section Local additions.
misc,
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 misc.
Most packages come with some form of documentation: user manuals, example files, programming guides, etc. In addition, many independent files not part of a macro or other package describe various aspects of the TeX system.
The TDS specifies that these additional documentation files shall
be stored in a structure that parallels to some extent the
fonts and tex directories, as follows:
texmf/doc/category/...
category identifies the general topic of documentation
that resides below it; for example, a TeX format name (latex),
program name (bibtex, tex), language (french,
german), or other system components (web, fonts).
The TDS reserves the following categories:
base is reserved for base documentation distributed by
the format's maintainers.
general,
for standalone documents not specific to any
particular program (for example, Joachim Schrod's Components
of TeX).
help,
for meta-information, such as FAQ's, David
Jones' macro index, etc.
html,
for HTML documents.
info,
for processed Texinfo documents. (Info files, like
anything else, may also be stored outside the TDS, at the
installer's option.)
local,
for local additions. See Section Local additions.
The doc directory is intended for implementation-independent and
operating system-independent documentation
files. Implementation-dependent files shall be stored elsewhere, as
provided for by the implementation and/or TeX administrator (for
example, VMS help files under texmf/vms/help).
The documentation directories may contain TeX sources, DVI files, PostScript files, text files, example input files, or any other useful documentation format(s).
See Section Documentation tree summary for a summary.
New programs that are extensions of old ones shall use a new top-level directory name for their extension-specific input files. The new directory shall have the same general structure as the top-level directory of the original program, and the new program almost certainly should search the original top-level directory.
For example, several variants of TeX that recognize additional
commands have been released. Input files that use these new commands
cannot be placed in the top-level tex directory, since the
original TeX program cannot read them. So they must go in a new
directory, with the same package structure as tex (see
Section Macros).
Using e-TeX as an example, we have the following:
texmf) directory etex.
texmf/etex
follows the same conventions as texmf/tex.
texmf/etex contains only e-TeX-specific files.
texmf/etex, then texmf/tex.
These same principles hold for PDFTeX, Omega, and (most probably) future variants of TeX or METAFONT.
A skeleton of a TDS texmf directory tree. This is not to
imply these are the only entries allowed. For example, local may
occur at any level.
bibtex/ BibTeX input files
bib/ BibTeX databases
base/ base distribution (e.g., xampl.bib)
misc/ single-file databases
<package>/ name of a package
bst/ BibTeX style files
base/ base distribution (e.g., plain.bst, acm.bst)
misc/ single-file styles
<package>/ name of a package
doc/ see Section Documentation and the summary below
etex/ as with tex, below
fonts/ font-related files
<type>/ file type (e.g., pk)
<mode>/ type of output device (for pk and gf only)
<supplier>/ name of a font supplier (e.g., public)
<typeface>/ name of a typeface (e.g., cm)
dpi<nnn>/ font resolution (for pk and gf only)
<implementation>/ TeX implementations, by name (e.g., emtex)
local/ files created or modified at the local site
metafont/ METAFONT (non-font) input files
base/ base distribution (e.g., plain.mf)
misc/ single-file packages (e.g., modes.mf)
<package>/ name of a package (e.g., mfpic)
metapost/ MetaPost input and support files
base/ base distribution (e.g., plain.mp)
misc/ single-file packages
<package>/ name of a package
support/ support files for MetaPost-related utilities
mft/ MFT inputs (e.g., plain.mft)
<program>/ TeX-related programs, by name (e.g., dvips)
source/ program source code by name (e.g., latex, web2c)
tex/ TeX input files
<format>/ name of a format (e.g., plain)
base/ base distribution for format (e.g., plain.tex)
misc/ single-file packages (e.g., webmac.tex)
local/ local additions to or local configuration files for graphics, mfnfss)
generic/ format-independent packages
hyphen/ hyphenation patterns (e.g., hyphen.tex)
images/ image input files (e.g., Encapsulated PostScript)
misc/ single-file format-independent packages (e.g., null.tex).
<package>/ name of a package (e.g., babel)
A skeleton of a TDS directory tree under texmf/doc. This
is not to imply these are the only entries allowed.
ams/
amsfonts/ amsfonts.faq, amfndoc
amslatex/ amslatex.faq, amsldoc
amstex/ amsguide, joyerr
bibtex/ BibTeX
base/ btxdoc.tex
fonts/
fontname/ Filenames for TeX fonts
oldgerm/ corkpapr
<format>/ name of a TeX format (e.g., generic, latex)
base/ for the base distribution
misc/ for contributed single-file package documentation
<package>/ for package
general/ across programs, generalities
errata/ errata, errata[1-8]
texcomp/ Components of TeX
generic/ for non-format-specific TeX packages
babel/
german/ germdoc
help/ meta-information
ctan/ info about CTAN mirror sites
faq/ FAQs of comp.text.tex, etc.
html/ HTML files
info/ GNU Info files, made from Texinfo sources
latex/ example of ltnews*, *guide, etc.
graphics/ grfguide
local/ site-specific documentation
<program>/ TeX-related programs, by name (examples follow)
metafont/ mfbook.tex, metafont-for-beginners, etc.
metapost/ mpman, manfig, etc.
tex/ texbook.tex, A Gentle Introduction to TeX, etc.
web/ webman, cwebman
The TDS cannot address the following aspects of a functioning TeX system:
texmf tree altogether (e.g.,
/usr/local/bin), in a platform-dependent directory within
texmf, or elsewhere.
texmf that would do more
good than harm, or that would be practical for even a plurality of
installations.
.fmt files): by their nature, these must be left to the
implementor or TeX maintainer. See Section Example implementation-specific trees.
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.
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:
A-Z, 0-9, and underscore.
Lowercase letters are excluded.
FILENAME. or .EXT).
FILENAME.EXT;1).
texmf/L2/L3/L4/L5/L6/L7/L8/FOO.BAR;1
1 2 3 4 5 6 7 8
The deepest TDS path needs only seven levels:
texmf/fonts/pk/cx/public/cm/dpi300/cmr10.pk
1 2 3 4 5 6 7
Some systems display a modified format of ISO-9660 names, mapping alphabetic characters to lowercase, removing version numbers and trailing periods, etc.
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.
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 "drop-in" distribution packages for TeX.
[This section is retained for historical purposes; the TDS is now quite firmly entrenched in most TeX distributions.]
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:
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 Related references 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.
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 OS and package dependencies, package interdependencies, and other details not addressed by this TDS version.
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.
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.
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.
Recursive subdirectory searching is the ability to specify a search not
only of a specified directory d, but recursively of all
directories below d.
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.
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&YTeX. The Kpathsea library is a reusable implementation of subdirectory searching for TeX, used in a number of the above programs.
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.
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 Subdirectory searching. 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.
Different implementations specify subdirectory searching differently.
In the interest of typographic clarity, the examples here do not use the
replaceable font.
TEXFONTS_SUBDIR environment variable.
t:\subdir!!; t:\subdir! for
a single level of searching.
texmf/subdir//
texmf:[subdir...]
texmf/subdir/**;
texmf/subdir/* for a single level of searching. Version 20.50
and above support the // notation.
t:/subdir// or
t:\subdir\\.
The TDS cannot specify a precise location for
implementation-specific files, such as texmf/ini, because a site
may have multiple TeX implementations.
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.
We recommend all implementations have default search paths that start
with the current directory (e.g., .). Allowing users to
include the parent directory (e.g., ..) is also helpful.
(Email scherer@physik.rwth-aachen.de to contact the maintainer of this implementation.)
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.
Thanks to the SELFAUTO 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.
In addition to Kpathsea's // notation recursive path search may
also be started by DEVICE:/, e.g., TeXMF:/
will scan this specific device completely.
Binaries coming with the AmiWeb2c distribution are installed in the
directory bin/amiweb2c/ outside the common TDS tree
share/texmf/. In addition to the set of AmiWeb2c binaries
you will find two subdirectories local/ and pastex/
with auxiliary programs.
A stripped version of the PasTeX system (used by kind permission of
Georg Heßmann) is coming with AmiWeb2c, pre-installed in its own
share/texmf/amiweb2c/pastex/ directory. If you want to use
PasTeX you have to assign the name TeX: to this place.
Documentation files in AmigaGuide format should be stored at
doc/guide/ similar to doc/info/.
If another VMS implementation besides Public DECUS TeX
appears, the top level implementation directory name will be modified to
something more specific (e.g., vms_decus).
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
All implementation-dependent TeX system files (.pool,
.fmt, .base, .mem) are stored by default directly
in texmf/web2c. The configuration file texmf.cnf and
various subsidiary MakeTeX... scripts used as subroutines are
also stored there.
Non-TeX specific files are stored following the GNU coding
standards. Given a root directory prefix
(/usr/local by default), we have default locations as follows:
<prefix>/ installation root (/usr/localby default) bin/ executables man/ man pages info/ info files lib/ libraries (libkpathsea.*) share/ architecture-independent files texmf/ TDS root web2c/ implementation-dependent files (.pool,.fmt,texmf.cnf, etc.)
See ftp://ftp.gnu.org/pub/gnu/GNUinfo/standards.text 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 /usr/local/texmf.
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 "made sense").
Some interesting ideas could not be applied due to implementations lacking the necessary support:
texmf 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.
The TWG settled on the
format/package arrangement after long
discussion about how best to arrange the files.
The primary alternative to this arrangement was a scheme which reversed
the order of these directories:
package/format. 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).
Nevertheless, the format/package
structure won for a couple of reasons:
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.
We considered the supplier-first arrangement in use at many sites:
texmf/fonts/supplier/typeface/type/
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
TFM file, the simplest implementation would require TeX to
search through all the directories that contain PK files in all
modes and at all resolutions.
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.
We also considered segregating all font-related files strictly by file
type, so that METAFONT sources would be in a directory
texmf/fonts/mf, property list files in texmf/fonts/pl, the
various forms of Type 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
(mf and pl under source, pfa and pfb
and gsf under type1) where beneficial.
We considered having the mode at the bottom of the font tree:
texmf/fonts/pk/supplier/typeface/mode/dpi/
In this case, however, it is difficult to limit subdirectory searching to the mode required for a particular device.
We then considered moving the dpinnn up to below
the mode:
texmf/fonts/pk/mode/dpi/supplier/typeface/
But then it is not feasible to omit the dpinnn
level altogether on systems which can and do choose to use long
filenames.
The TDS specifies using a single directory modeless/ as
the mode name for those utilities which generate bitmaps, e.g.,
texmf/fonts/modeless/times/. This has the considerable advantage
of not requiring each such directory name to be listed in a search path.
An alternative was to use the utility name below which all such
directories could be gathered. That has the advantage of separating,
say, gsftopk-generated bitmaps from ps2pk-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 PK_ID byte.
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 mfcx vs.
xyzcx 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 happen.
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.
We hope that a separate, but parallel, structure for documentation would (1) keep the documentation together and (2) make it as straightforward as possible for users to find the particular documentation they were after.
This appendix gives pointers to related files and other documents.
In this document, CTAN: means the root of an
anonymous ftp CTAN tree. This is both a host name and a directory
name. For example:
http://www.ctan.org/tex-archive
ftp://ctan.tug.org/tex-archive
ftp://ftp.dante.de/tex-archive
ftp://ftp.tex.ac.uk/tex-archive
In the references below, we use specific top-level url's only to make the links be live in this document. See http://www.ctan.org/tex-archive/CTAN.sites for a complete list of CTAN sites, there are mirrors worldwide.
Here are the references:
The TWG had no physical meetings; electronic mail was the communication medium.
Sebastian Rahtz is the TeX Users Group Technical Council liaison. Norman Walsh is the committee chair.
Contributors:
David Aspinall, Nelson Beebe, Barbara Beeton, Karl Berry, Harriet Borton, Vicki Brown, David Carlisle, Bart Childs, Damian Cugley, Alan Dunwell, Thomas Esser, Michael Ferguson, Erik Frambach, Bernard Gaulle, Jeffrey Gealow, George Greenwade, Thomas Herter, Berthold Horn, Alan Jeffrey, Charles Karney, David Kastrup, David Kellerman, Wonkoo Kim, Richard Kinch, Robin Kirkham, Jörg Knappen, Alex Kok, Pierre MacKay, Eberhard Mattes, Rich Morin, Bob Morris, Lenny Muellner, Oren Patashnik, Sebastian Rahtz, David Rhead, Andreas Scherer, Joachim Schrod, Mark Sinke, Christian Spieler, Elizabeth Tachikawa, Philip Taylor, Andrew Trevorrow, Ulrik Vieth, Paul Vojta, Norman Walsh. Doug Waud, Olaf Weber, Chee-Wai Yeung.