4 Many places in the source tree have extractable documentation in the
5 form of block comments above functions. The components of this system
10 This is a perl script that hunts for the block comments and can mark
11 them up directly into DocBook, man, text, and HTML. (No, not
14 - Documentation/DocBook/*.tmpl
16 These are SGML template files, which are normal SGML files with
17 special place-holders for where the extracted documentation should
22 This is a program for converting SGML template files into SGML
23 files. It invokes kernel-doc, giving it the list of functions that
26 - scripts/gen-all-syms
28 This is a script that lists the EXPORT_SYMBOL symbols in a list of C
33 This script invokes docproc, telling it which functions are to be
34 documented (this list comes from gen-all-syms).
38 The targets 'sgmldocs', 'psdocs', 'pdfdocs', and 'htmldocs' are used
39 to build DocBook files, PostScript files, PDF files, and html files
40 in Documentation/DocBook.
42 - Documentation/DocBook/Makefile
44 This is where C files are associated with SGML templates.
47 How to extract the documentation
48 --------------------------------
50 If you just want to read the ready-made books on the various
51 subsystems (see Documentation/DocBook/*.tmpl), just type 'make
52 psdocs', or 'make pdfdocs', or 'make htmldocs', depending on your
53 preference. If you would rather read a different format, you can type
54 'make sgmldocs' and then use DocBook tools to convert
55 Documentation/DocBook/*.sgml to a format of your choice (for example,
56 'db2html ...' if 'make htmldocs' was not defined).
58 If you want to see man pages instead, you can do this:
61 $ scripts/kernel-doc -man $(find -name '*.c') | split-man.pl /tmp/man
62 $ scripts/kernel-doc -man $(find -name '*.h') | split-man.pl /tmp/man
70 die "where do I put the results?\n";
76 if (/^\.TH \"[^\"]*\" (\d) \"([^\"]*)\"/) {
77 if ($state == 1) { close OUT }
79 $fn = "$ARGV[0]/$2.$1";
80 print STDERR "Creating $fn\n";
81 open OUT, ">$fn" or die "can't open $fn: $!\n";
83 } elsif ($state != 0) {
91 If you just want to view the documentation for one function in one
92 file, you can do this:
94 $ scripts/kernel-doc -man -function fn file | nroff -man | less
98 $ scripts/kernel-doc -text -function fn file
101 How to add extractable documentation to your source files
102 ---------------------------------------------------------
104 The format of the block comment is like this:
107 * function_name(:)? (- short description)?
108 (* @parameterx: (description of parameter x)?)*
110 * (Description:)? (Description of function)?
111 * (section header: (section description)? )*
114 The short function description cannot be multiline, but the other
115 descriptions can be (and they can contain blank lines). Avoid putting a
116 spurious blank line after the function name, or else the description will
119 All descriptive text is further processed, scanning for the following special
120 patterns, which are highlighted appropriately.
122 'funcname()' - function
123 '$ENVVAR' - environment variable
124 '&struct_name' - name of a structure (up to two words including 'struct')
125 '@parameter' - name of a parameter
126 '%CONST' - name of a constant.
128 Take a look around the source tree for examples.
131 How to make new SGML template files
132 -----------------------------------
134 SGML template files (*.tmpl) are like normal SGML files, except that
135 they can contain escape sequences where extracted documentation should
138 !E<filename> is replaced by the documentation, in <filename>, for
139 functions that are exported using EXPORT_SYMBOL: the function list is
140 collected from files listed in Documentation/DocBook/Makefile.
142 !I<filename> is replaced by the documentation for functions that are
143 _not_ exported using EXPORT_SYMBOL.
145 !F<filename> <function [functions...]> is replaced by the
146 documentation, in <filename>, for the functions listed.
150 */ <twaugh@redhat.com>