19.2 Environment Variables Recognized by texi2any

texi2any also reads the environment variable TEXINFO_OUTPUT_FORMAT to determine the output format, if not overridden by a command line option. The value should be one of:

docbook  dvi  dvipdf  epub3  html  info  latex  pdf  plaintext  ps  xml

If not set or otherwise specified, Info output is the default.

TEXINFO_OUTPUT_FORMAT may take some other special values, which do not correspond to any command-line settable output format (see Customization Variables and Options).

The customization variable of the same name is also read; if set, that overrides an environment variable setting, but not a command-line option. See Customization Variables and Options.

You can control texi2any’s use of Perl extension modules by setting the TEXINFO_XS environment variable. These modules are compiled native code that the interpreted Perl code can use. Ideally, these extension modules should just work, and the only noticeable difference they should make is that texi2any finishes running sooner. However, you can use this environment variable for the purposes of troubleshooting: for example, if you have problems with the output of texi2any varying depending on whether the extension modules are in use.

The following values of TEXINFO_XS are recognized by texi2any:


The default behavior. Try to load extension modules, and silently fall back to the interpreted Perl implementations if this fails.


Try to load extension modules, and if this fails, give a warning message before falling back to the interpreted Perl implementations.


Try to load extension modules, printing many messages while doing so.


Do not use extension modules.

Set TEXINFO_XS_PARSER to ‘0’ to disable the use of the native code implementation of the parser module. This is the part of texi2any that converts Texinfo input into an internal tree format used for further processing into output formats. This may be useful for working around bugs or incompatibilities between the native code implementation and the implementation in pure Perl code.