noindex(1) build external index for noweb document


noindex basename[.tex]


noindex looks through LaTeX .aux files for identifiers that should go in a noweb external index. It sorts all identifiers and writes the results on basename.nwi.


A noweb program consists of one or more files. In the simple case, these files are run through noweave together, to produce a single LaTeX file. noweave -index suffices to produce an index and cross-referencing information; neither nodefs nor noindex is required.

When a noweb program consists of several source files, it is often better to run each source file through noweave to produce its own LaTeX file, then use noindex to produce an external index. This technique has several advantages:

The line numbers in the LaTeX files correspond to the line numbers in the source files, so it is easier to diagnose LaTeX errors.
The LaTeX \\includeonly feature can be used, making it possible to format parts of large programs while retaining complete cross-reference information.
When used with make(1), the technique avoids running noweave over source files that have not changed.
Using the external index places fewer demands on LaTeX's memory, making it read its .aux files much more quickly.

The disadvantages are that nodefs and noindex are needed for full cross-referencing and a properly sorted index.


This example assumes a noweb program of three source files: a.nw , b.nw , and c.nw. The file doc.tex is assumed to contain LaTeX boilerplate, including the commands

The first sequence of steps is to create a file listing all the identifiers defined anywhere in a, b, or c.

nodefs a.nw > a.defs
nodefs b.nw > b.defs
nodefs c.nw > c.defs
sort -u a.defs b.defs c.defs | cpif all.defs

Using sort -u and cpif(1) avoids changing all.defs unless the set of identifiers changes. This technique, used in a Makefile, avoids unnecessary rebuilding.

The next series of steps is to create LaTeX files with full cross-reference information for all identifiers.

noweave -n -indexfrom all.defs a.nw > a.tex
noweave -n -indexfrom all.defs b.nw > b.tex
noweave -n -indexfrom all.defs c.nw > c.tex

The final steps run LaTeX once to create .aux files, then noindex to create the index, then LaTeX again to format the complete document.

latex doc
noindex doc
latex doc

In a Makefile, noindex can be run before every invocation of LaTeX.


noindex is distributed in awk and Icon versions. The awk version is slow and does a poorer job sorting.

There is no comparable machinery to make it possible to use multiple files with the HTML back end.


This man page is from noweb version 2.11b.


Norman Ramsey, Harvard University. Internet address [email protected].
Noweb home page at