--- name: "noweb" section: "1" platform: "linux" package: "noweb" version: "2.13-2" release: "Debian 13 (Trixie)" platforms: ["linux"] url: "https://new.carta.tech/noweb" --- # noweb(1) a simple literate-programming tool ## NAME noweb - a simple literate-programming tool ## SYNOPSIS **noweb** \[**-t**\] \[**-o**\] \[**-L***format*\] \[**-markup** *parser*\] \[file\] ... ## DESCRIPTION *Noweb* is a literate-programming tool like *FunnelWEB* or *nuweb*, only simpler. A *noweb* file contains program source code interleaved with documentation. When *noweb* is invoked, it writes the program source code to the output files mentioned in the noweb file, and it writes a *TeX* file for typeset documentation. The [*noweb*(1)](/noweb/1.md) command is for people who don't like reading man pages or who are switching from *nuweb*. To get the most out of *noweb*, use [*notangle*(1)](/notangle/1.md) and [*noweave*(1)](/noweave/1.md) instead. ## FORMAT OF NOWEB FILES A *noweb* file is a sequence of *chunks*, which may appear in any order. A chunk may contain code or documentation. Documentation chunks begin with a line that starts with an at sign (@) followed by a space or newline. They have no names. Code chunks begin with\ \<\<*chunk name*\>\>=\ on a line by itself. The double left angle bracket (\<\<) must be in the first column. Chunks are terminated by the beginning of another chunk, or by end of file. If the first line in the file does not mark the beginning of a chunk, it is assumed to be the first line of a documentation chunk. Documentation chunks contain text that is copied verbatim to the *TeX* file (except for quoted code). *noweb* works with *LaTeX*; the first documentation chunk must contain a *LaTeX* **\\\\documentclass** command, it must contain **\\\\usepackage{noweb}** in the preamble, and finally it must also contain a *LaTeX* **\\\\begin{document}** command. Code chunks contain program source code and references to other code chunks. Several code chunks may have the same name; *noweb* concatenates their definitions to produce a single chunk, just as other literate-programming tools do. *noweb* looks for chunks that are defined but not used in the source file. If the name of such a chunk contains no spaces, the chunk is an \`\`output file;'' *noweb* expands it and writes the result onto the file of the same name. A code-chunk definition is like a macro definition; it contains references to other chunks, which are themselves expanded, and so on. *noweb*'s output is readable; it preserves the indentation of expanded chunks with respect to the chunks in which they appear. If a star (**\***) is appended to the name of an output file, *noweb* includes line-number information as specified by the **-L***format* option (or for C if no **-L***format* option is given). The name itself may not contain shell metacharacters. Code may be quoted within documentation chunks by placing double square brackets (**\[\[***...***\]\]**) around it. These double square brackets are used to give the code special typographic treatment in the *TeX* file. If quoted code ends with three or more square brackets, *noweb* chooses the rightmost pair, so that, for example, **\[\[a\[i\]\]\]** is parsed correctly. In code, noweb treats unpaired double left or right angle brackets as literal **\<\<** and **\>\>**. To force any such brackets, even paired brackets or brackets in documentation, to be treated as literal, use a preceding at sign (e.g. **@\<\<**). ## OPTIONS - **-t** Suppress generation of a *TeX* file. - **-o** Suppress generation of output files. - **-L*format*** Use *format* to format line-number information for starred output files. (If the option is omitted, a format suitable for C is used.) *format* is as defined by [*notangle*(1)](/notangle/1.md); - **-markup *parser*** Use *parser* to parse the input file. Enables use of noweb tools on files in other formats; for example, the **numarkup** parser understands *nuweb*(1) format. See [*nowebfilters*(7)](/nowebfilters/7.md) for more information. For experts only. ## BUGS Ignoring unused chunks whose names contain spaces sometimes causes problems, especially in the case when a chunk has multiple definitions and one is misspelled; the misspelled definition will be silently ignored. [*noroots*(1)](/noroots/1.md) can be used as a sanity checker to catch this sort of mistake. *noweb* is intended for users who don't want the power or the complexity of command-line options. More sophisticated users should avoid *noweb* and use *noweave* and *notangle* instead. If the design were better, we could all use the same commands. *noweb* requires the new version of *awk*. DEC *nawk* has a bug in that that causes problems with braces in *TeX* output. GNU *gawk* is reported to work. The default *LaTeX* pagestyles don't set the width of the boxes containing headers and footers. Since *noweb* code paragraphs are extra wide, this *LaTeX* bug sometimes results in extra-wide headers and footers. The remedy is to redefine the relevant **ps@\*** commands; **ps@noweb** in **noweb.sty** can be used as an example. ## SEE ALSO [*notangle*(1)](/notangle/1.md), [*noweave*(1)](/noweave/1.md), [*noroots*(1)](/noroots/1.md), [*nountangle*(1)](/nountangle/1.md), [*nowebstyle*(7)](/nowebstyle/7.md), [*nowebfilters*(7)](/nowebfilters/7.md), [*nuweb2noweb*(1)](/nuweb2noweb/1.md)\ Norman Ramsey, *Literate programming simplified, IEEE Software* 11(5):97-105, September 1994. ## VERSION This man page is from *noweb* version 2.12. ## AUTHOR Norman Ramsey, Tufts University. Internet address **Norman.Ramsey@tufts.edu**.\ Noweb home page at **http://www.cs.tufts.edu/~nr/noweb**.