1TANGLE(1)                   General Commands Manual                  TANGLE(1)
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NAME

6       tangle - translate WEB to Pascal
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SYNOPSIS

9       tangle  [options] webfile[.web] [ { changefile[.ch] |-} [ outfile[.p] ]
10       ]
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DESCRIPTION

13       This manual page is not meant to be exhaustive.  The complete  documen‐
14       tation  for this version of TeX can be found in the info file or manual
15       Web2C: A TeX implementation.
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17       The tangle program converts a Web source document into a Pascal program
18       that  may be compiled in the usual way with the on-line Pascal compiler
19       (e.g., pc(1)).  The output file is packed into lines of  72  characters
20       or  less, with the only concession to readability being the termination
21       of lines at semicolons when this can be done conveniently.
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23       The Web language allows you to prepare a single document containing all
24       the information that is needed both to produce a compilable Pascal pro‐
25       gram and to produce a well-formatted document describing the program in
26       as  much  detail as the writer may desire.  The user of Web must be fa‐
27       miliar with both TeX and Pascal.  Web also provides a  relatively  sim‐
28       ple, although adequate, macro facility that permits a Pascal program to
29       be written in small easily-understood modules.
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31       The command line should have one, two or three names on it.  The  first
32       is  taken as the Web file (and .web is added if there is no extension).
33       If there is second name, it is a change file (and .ch is added if there
34       is  no extension).  The change file overrides parts of the Web file, as
35       described in the Web system documentation.
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37       If there is a third name, it is the Pascal output file (and .p is added
38       if there is no extension). In this case you can specify an empty change
39       file with '-' as the second argument.  Otherwise the name of the Pascal
40       file is formed by adding .p to the root of the Web file name.
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42       An  optional  second  output  file is a string pool file, whose name is
43       formed by adding .pool to the root of the Pascal file name.
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OPTIONS

46       This version of tangle understands the following  options.   Note  that
47       some  of  these options may render the output unsuitable for processing
48       by a Pascal compiler.
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50       --help Print help message and exit.
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52       --length number
53              Compare only the first number  characters  of  identifiers  when
54              checking for collisions.  The default is 32, the original tangle
55              used 7.
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57       --loose
58              When checking for collisions between identifiers, honor the set‐
59              tings of the --lowercase, --mixedcase, --uppercase, and --under‐
60              line options. This is the default.
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62       --lowercase
63              Convert all identifiers to lowercase.
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65       --mixedcase
66              Retain the case of identifiers.  This is the default.
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68       --strict
69              When checking for collisions between identifiers,  strip  under‐
70              lines and convert all identifiers to uppercase first.
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72       --underline
73              Retain underlines (also known as underscores) in identifiers.
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75       --uppercase
76              Convert  all identifiers to uppercase.  This is the behaviour of
77              the original tangle.
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79       --version
80              Print version information and exit.
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ENVIRONMENT

83       The environment variable WEBINPUTS is used  to  search  for  the  input
84       files,  or  the system default if WEBINPUTS is not set.  See tex(1) for
85       the details of the searching.
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SEE ALSO

88       pc(1), pxp(1) (for formatting tangle output when debugging), tex(1).
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90       Donald E. Knuth, The Web System of Structured Documentation.
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92       Donald E. Knuth, Literate Programming,  Computer  Journal  27,  97-111,
93       1984.
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95       Wayne  Sewell,  Weaving  a  Program,  Van Nostrand Reinhold, 1989, ISBN
96       0-442-31946-0.
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98       Donald E. Knuth, TeX: The Program (Volume B of Computers  and  Typeset‐
99       ting), Addison-Wesley, 1986, ISBN 0-201-13437-3.
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101       Donald E. Knuth, Metafont: The Program (Volume D of Computers and Type‐
102       setting), Addison-Wesley, 1986, ISBN 0-201-13438-1.
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104       These last two are by far the largest extant examples of Web programs.
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106       There is an active Internet electronic mail discussion list on the sub‐
107       ject  of  literate programming; send a subscription request to litprog-
108       request@shsu.edu to join.
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AUTHORS

111       Web was designed by Donald E. Knuth, based on an earlier system  called
112       DOC (implemented by Ignacio Zabala).  The tangle and weave programs are
113       themselves written in Web. The system was originally ported to Unix  at
114       Stanford by Howard Trickey, and at Cornell by Pavel Curtis.
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118Web2C 2022                       02 March 2022                       TANGLE(1)