4 This guide presents the structure and conventions of the LTTng
5 Documentation's source. Make sure you read it thoroughly before
12 `toc/docs.yml` is a YAML tree of all chapters, sections and subsections.
13 It indicates which unique ID is linked to which position in the
14 hierarchy and its true title.
16 In the `contents` directory, the `preface.md` file is the preface contents.
17 Each chapter has its own directory (directory names are not significant).
18 Within those, `intro.md` files are partial introductions and then each
19 section has its own directory, and so on, unless a section has no
20 subsections, in which case all its contents is in a single Markdown file
21 named _more or less_ like its ID.
23 Each Markdown file begins with a YAML front matter which only contains
24 the unique ID of this chapter/section:
28 id: unique-id-goes-here
31 First paragraph goes here.
34 Editable image sources are placed in `images/src` and their rendered
35 equivalents are located in `images/export`.
37 `tools/checkdocs.py` is a Python 3 script which may be used to find
38 typical errors in the whole documentation (dead internal links,
39 common grammar mistakes, etc.). It needs the
40 [`termcolor`](https://pypi.python.org/pypi/termcolor) Python package.
41 Run it from the repository's root:
45 and it will potentially output a list of errors and warnings.
51 The sources are made of a fusion of Markdown and HTML processed by
52 [kramdown](http://kramdown.gettalong.org/). Markdown is preferred,
53 HTML being only used for specific cases that need special formatting
54 not available using plain Markdown. The kramdown processor is clever
55 enough to support both languages in the same file, even in the same
61 Here's a list of HTML blocks and inline code used throughout the
62 document. If you need to contribute, please use them when needed to
63 preserve the document's visual consistency.
73 <span class="t">Title goes here followed by colon:</span>Text goes
77 Multiple paragraphs is allowed.
82 Title should be `Tip:` for a tip and `Note:` for a note.
87 Internal links should always use Markdown
88 (`[caption](#doc-section)`). External links, however, need a special
89 style and must use the `<a>` tag with the `ext` CSS class:
92 The LTTng Documentation is
93 <a href="https://github.com/lttng/lttng-docs" class="ext">public</a>.
96 Sometimes, however, it is necessary to write internal links in plain
97 HTML, for example in tip blocks, since Markdown code is not processed.
98 In these cases, add the `int` CSS class as a hint to prevent the static
99 analyzer from complaining (`tools/checkdocs.py`).
104 Use `<abbr>` for describing abbreviations. This should only be used
105 for the first use of the abbreviation:
108 The <abbr title="Linux Trace Toolkit: next generation">LTTng</abbr>
109 project is an open source system software package [...]
113 #### non-breaking spaces
115 Sometimes, a non-breaking space HTML entity (` `) needs to be
121 The size of this file is 1039 bytes.
123 This integer is displayed in base 16.
125 A check is performed every 3000 ms.
129 #### placeholders in inline code
131 You must use `<em>` to emphasize a placeholder within a `<code>` tag
132 because Markdown backticks (<code>`</code>) always render their
136 Name your file <code>something_<em>sys</em>.c</code>, where
137 <code><em>sys</em></code> is your system name.
143 A terminal box, where command lines are shown, is a simple `<pre>`
144 with the `term` class:
148 echo This is a terminal box
152 Do not prefix command lines with prompts (`$`/`#`) since this makes
153 copy/paste operations painful.
155 You may use `<strong>` tags to emphasize a part of the command line:
159 echo This is a <strong>terminal</strong> box
163 Results of commands, if needed, should be presented in a simple
164 `text` kramdown code block:
168 [15:30:34.835895035] (+?.?????????) hostname hello_world: { cpu_id = 1 }, { my_int = 8, char0 = 68, char1 = 97, product = "DataTraveler 2.0" }
169 [15:30:42.262781421] (+7.426886386) hostname hello_world: { cpu_id = 1 }, { my_int = 9, char0 = 80, char1 = 97, product = "Patriot Memory" }
170 [15:30:48.175621778] (+5.912840357) hostname hello_world: { cpu_id = 1 }, { my_int = 10, char0 = 68, char1 = 97, product = "DataTraveler 2.0" }
180 <div class="img img-70">
181 <img src="/images/docs/image-name.png" alt="Short description">
185 to display an image. Change `img-70` to `img-` followed by the
186 width percentage you wish.
188 The SVG format is preferred. In this case, use the `<object>` tag to
189 render an interactive SVG, with an inner raster image fallback for
193 <div class="img img-90">
194 <object data="/images/docs/image-name.svg" type="image/svg+xml">
195 <img src="/images/docs/image-name.png" alt="Short description">
200 An interactive SVG object allows its text to be selected, amongst other
207 A few rules to comply with in order to keep the text as
208 consistent as possible:
210 * Use _user space_, not _userspace_ nor _user-space_.
211 (neither _user land_).
212 * Use _file system_, not _filesystem_.
213 * Use _use case_, not _use-case_ nor _usecase_.
214 * Use _the C standard library_, not _libc_.
215 * Use _log level_, not _loglevel_.
216 * Use complete LTTng project names: _LTTng-modules_, _LTTng-UST_ and
217 _LTTng-tools_, not _modules_, _UST_ and _tools_.
218 * All code snippets should use 4 spaces for indentation (even C)
219 so that they are not too large.
220 * Prefer emphasis (Markdown: `_something_`, HTML: `<em>something</em>`)
221 to strong (Markdown: `**something**`, HTML: `<strong>something</strong>`)
222 for emphasizing text.
223 * Try to stay behind the 72th column mark if possible, and behind
224 the 80th column otherwise.
225 * Do not end directory paths with a forward slash
226 (good: `include/trace/events`, bad: `include/trace/events/`).
227 * Keep the text as impersonal as possible (minimize the use of
228 _I_, _we_, _us_, etc.), except for user guides/tutorials where
229 _we_ have an ongoing example.
235 If you make a change to a single contents file, prefix your Git commit
236 message's first line with the file ID followed by `: `, e.g: