TeX needs to find the texinfo.tex file that the ‘\input texinfo’ command on the first line reads. The texinfo.tex file tells TeX how to handle @-commands; it is included in all standard GNU distributions. The latest version released for general use is available from the usual GNU servers and mirrors:
The latest development version is available from the Texinfo source repository:
texinfo.tex is essentially a standalone file, so, if you need or want to try a newer version than came with your system, it nearly always suffices to download it and put it anywhere that TeX will find it. You can replace any existing texinfo.tex with a newer version (of course saving the original in case of disaster).
Also, you should install epsf.tex, if it is not already installed
from another distribution. More details are at the end of the description
of the @image command (see Inserting Images).
To use quotation marks other than those used in English, you’ll need to have the European Computer Modern fonts (e.g., ecrm1000) and (for PDF output) CM-Super fonts (see Inserting Quotation Marks).
To use the @euro command, you’ll need the ‘feym*’ fonts
(e.g., feymr10). See @euro (€): Euro Currency Symbol.
All of the above files should be installed by default in a reasonable TeX installation.
Optionally, you may create a file texinfo.cnf for site configuration. When processing a Texinfo file, TeX looks for this file in its search path, which includes the current directory and standard installation directories. You can use this file for local conventions. For example, if texinfo.cnf contains the line ‘@afourpaper’ (see Printing on A4 Paper), then all Texinfo documents will be processed with that page size in effect. If you have nothing to put in texinfo.cnf, you do not need to create it.
You can set the TEXINPUTS environment variable
to allow TeX to find texinfo.cnf.
(This also works for texinfo.tex and any other file TeX
might read). For example, if you are using a Bourne shell-compatible shell
(sh, bash, ksh, …), your .profile file
could contain the lines:
TEXINPUTS=.:/home/me/mylib: export TEXINPUTS
These settings would cause TeX first to look for an \input file in the current directory, indicated by the ‘.’, then in a hypothetical user ‘me’’s mylib directory, and finally in the system directories. (A leading, trailing, or doubled ‘:’ indicates searching the system directories at that point.)