# phpman > man > otangle(1)


*Source: tldr-pages*

---

[TANGLE(1)](https://www.chedong.com/phpMan.php/man/TANGLE/1/markdown)                              General Commands Manual                             [TANGLE(1)](https://www.chedong.com/phpMan.php/man/TANGLE/1/markdown)



## NAME
       tangle - translate WEB to Pascal

## SYNOPSIS
       **tangle** [_options_] _webfile_[**.web**] [_changefile_[**.ch**]]

## DESCRIPTION
       This  manual page is not meant to be exhaustive.  The complete documentation for this version
       of TeX can be found in the info file or manual _Web2C:_ _A_ _TeX_ _implementation_.

       The **tangle** program converts a Web source document into a Pascal program that may be  compiled
       in  the  usual way with the on-line Pascal compiler (e.g., [**pc**(1)](https://www.chedong.com/phpMan.php/man/pc/1/markdown)).  The output file is packed
       into lines of 72 characters or less, with the only concession to readability being the termi‐
       nation of lines at semicolons when this can be done conveniently.

       The  Web language allows you to prepare a single document containing all the information that
       is needed both to produce a compilable Pascal program and to produce a  well-formatted  docu‐
       ment describing the program in as much detail as the writer may desire.  The user of Web must
       be familiar with both TeX and Pascal.  Web also provides a relatively simple,  although  ade‐
       quate,  macro facility that permits a Pascal program to be written in small easily-understood
       modules.

       The command line should have either one or two names on it.  The first is taken  as  the  Web
       file  (and **.web** is added if there is no extension).  If there is another name, it is a change
       file (and **.ch** is added if there is no extension).  The change file overrides parts of the Web
       file, as described in the Web system documentation.

       The  output  files are a Pascal file and a string pool file, whose names are formed by adding
       **.p** and **.pool** respectively to the root of the Web file name.

## OPTIONS
       This version of **tangle** understands the following options.  Note that some  of  these  options
       may render the output unsuitable for processing by a Pascal compiler.

       **--help** Print help message and exit.

       **--length** _number_
              Compare  only the first _number_ characters of identifiers when checking for collisions.
              The default is 32, the original **tangle** used 7.

### --loose
              When checking for collisions between identifiers, honor the settings of  the  **--lower**‐‐
              **case**, **--mixedcase**, **--uppercase**, and **--underline** options. This is the default.

### --lowercase
              Convert all identifiers to lowercase.

### --mixedcase
              Retain the case of identifiers.  This is the default.

### --strict
              When  checking  for  collisions  between identifiers, strip underlines and convert all
              identifiers to uppercase first.

### --underline
              Retain underlines (also known as underscores) in identifiers.

### --uppercase
              Convert all identifiers to uppercase.  This is the behaviour of the original **tangle**.

### --version
              Print version information and exit.

## ENVIRONMENT
       The environment variable WEBINPUTS is used to search for the input files, or the  system  de‐
       fault if WEBINPUTS is not set.  See [**tex**(1)](https://www.chedong.com/phpMan.php/man/tex/1/markdown) for the details of the searching.

## SEE ALSO
       [**pc**(1)](https://www.chedong.com/phpMan.php/man/pc/1/markdown), [**pxp**(1)](https://www.chedong.com/phpMan.php/man/pxp/1/markdown) (for formatting **tangle** output when debugging), [**tex**(1)](https://www.chedong.com/phpMan.php/man/tex/1/markdown).

       Donald E. Knuth, _The_ _Web_ _System_ _of_ _Structured_ _Documentation_.

       Donald E. Knuth, _Literate_ _Programming_, Computer Journal **27**, 97-111, 1984.

       Wayne Sewell, _Weaving_ _a_ _Program_, Van Nostrand Reinhold, 1989, ISBN 0-442-31946-0.

       Donald  E.  Knuth,  _TeX:_ _The_ _Program_ (Volume B of _Computers_ _and_ _Typesetting_), Addison-Wesley,
       1986, ISBN 0-201-13437-3.

       Donald E. Knuth, _Metafont:_ _The_ _Program_ (Volume D of _Computers_ _and_ _Typesetting_),  Addison-Wes‐
       ley, 1986, ISBN 0-201-13438-1.

       These last two are by far the largest extant examples of Web programs.

       There  is  an active Internet electronic mail discussion list on the subject of literate pro‐
       gramming; send a subscription request to <_litprog-request@shsu.edu_> to join.

## AUTHORS
       Web was designed by Donald E. Knuth, based on an earlier system called  DOC  (implemented  by
       Ignacio Zabala).  The **tangle** and **weave** programs are themselves written in Web. The system was
       originally ported to Unix at Stanford by Howard Trickey, and at Cornell by Pavel Curtis.



Web2C 2022/dev                              16 June 2015                                   [TANGLE(1)](https://www.chedong.com/phpMan.php/man/TANGLE/1/markdown)