Annotation of mandoc/man.3, Revision 1.4
1.4 ! kristaps 1: .\" $Id: man.3,v 1.3 2009/04/12 19:45:26 kristaps Exp $
1.1 kristaps 2: .\"
1.4 ! kristaps 3: .\" Copyright (c) 2009 Kristaps Dzonsons <kristaps@kth.se>
1.1 kristaps 4: .\"
5: .\" Permission to use, copy, modify, and distribute this software for any
1.3 kristaps 6: .\" purpose with or without fee is hereby granted, provided that the above
7: .\" copyright notice and this permission notice appear in all copies.
8: .\"
9: .\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10: .\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11: .\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12: .\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13: .\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14: .\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15: .\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
1.1 kristaps 16: .\"
17: .Dd $Mdocdate$
1.2 kristaps 18: .Dt MAN 3
1.1 kristaps 19: .Os
20: .\" SECTION
21: .Sh NAME
22: .Nm man_alloc ,
23: .Nm man_parseln ,
24: .Nm man_endparse ,
25: .Nm man_node ,
26: .Nm man_meta ,
27: .Nm man_free ,
28: .Nm man_reset
29: .Nd man macro compiler library
30: .\" SECTION
31: .Sh SYNOPSIS
32: .Fd #include <man.h>
33: .Vt extern const char * const * man_macronames;
34: .Ft "struct man *"
35: .Fn man_alloc "void *data" "int pflags" "const struct man_cb *cb"
36: .Ft void
37: .Fn man_reset "struct man *man"
38: .Ft void
39: .Fn man_free "struct man *man"
40: .Ft int
41: .Fn man_parseln "struct man *man" "int line" "char *buf"
42: .Ft "const struct man_node *"
43: .Fn man_node "struct man *man"
44: .Ft "const struct man_meta *"
45: .Fn man_meta "struct man *man"
46: .Ft int
47: .Fn man_endparse "struct man *man"
48: .\" SECTION
49: .Sh DESCRIPTION
50: The
51: .Nm man
52: library parses lines of
53: .Xr man 7
54: input (and
55: .Em only
56: man) into an abstract syntax tree (AST).
57: .\" PARAGRAPH
58: .Pp
59: In general, applications initiate a parsing sequence with
60: .Fn man_alloc ,
61: parse each line in a document with
62: .Fn man_parseln ,
63: close the parsing session with
64: .Fn man_endparse ,
65: operate over the syntax tree returned by
66: .Fn man_node
67: and
68: .Fn man_meta ,
69: then free all allocated memory with
70: .Fn man_free .
71: The
72: .Fn man_reset
73: function may be used in order to reset the parser for another input
74: sequence. See the
75: .Sx EXAMPLES
76: section for a full example.
77: .\" PARAGRAPH
78: .Pp
79: This section further defines the
80: .Sx Types ,
81: .Sx Functions
82: and
83: .Sx Variables
84: available to programmers. Following that, the
85: .Sx Abstract Syntax Tree
86: section documents the output tree.
87: .\" SUBSECTION
88: .Ss Types
89: Both functions (see
90: .Sx Functions )
91: and variables (see
92: .Sx Variables )
93: may use the following types:
94: .Bl -ohang -offset "XXXX"
95: .\" LIST-ITEM
96: .It Vt struct man
97: An opaque type defined in
98: .Pa man.c .
99: Its values are only used privately within the library.
100: .\" LIST-ITEM
101: .It Vt struct man_cb
102: A set of message callbacks defined in
103: .Pa man.h .
104: .\" LIST-ITEM
105: .It Vt struct man_node
106: A parsed node. Defined in
107: .Pa man.h .
108: See
109: .Sx Abstract Syntax Tree
110: for details.
111: .El
112: .\" SUBSECTION
113: .Ss Functions
114: Function descriptions follow:
115: .Bl -ohang -offset "XXXX"
116: .\" LIST-ITEM
117: .It Fn man_alloc
118: Allocates a parsing structure. The
119: .Fa data
120: pointer is passed to callbacks in
121: .Fa cb ,
122: which are documented further in the header file.
123: The
124: .Fa pflags
125: arguments are defined in
126: .Pa man.h .
127: Returns NULL on failure. If non-NULL, the pointer must be freed with
128: .Fn man_free .
129: .\" LIST-ITEM
130: .It Fn man_reset
131: Reset the parser for another parse routine. After its use,
132: .Fn man_parseln
133: behaves as if invoked for the first time.
134: .\" LIST-ITEM
135: .It Fn man_free
136: Free all resources of a parser. The pointer is no longer valid after
137: invocation.
138: .\" LIST-ITEM
139: .It Fn man_parseln
140: Parse a nil-terminated line of input. This line should not contain the
141: trailing newline. Returns 0 on failure, 1 on success. The input buffer
142: .Fa buf
143: is modified by this function.
144: .\" LIST-ITEM
145: .It Fn man_endparse
146: Signals that the parse is complete. Note that if
147: .Fn man_endparse
148: is called subsequent to
149: .Fn man_node ,
150: the resulting tree is incomplete. Returns 0 on failure, 1 on success.
151: .\" LIST-ITEM
152: .It Fn man_node
153: Returns the first node of the parse. Note that if
154: .Fn man_parseln
155: or
156: .Fn man_endparse
157: return 0, the tree will be incomplete.
158: .It Fn man_meta
159: Returns the document's parsed meta-data. If this information has not
160: yet been supplied or
161: .Fn man_parseln
162: or
163: .Fn man_endparse
164: return 0, the data will be incomplete.
165: .El
166: .\" SUBSECTION
167: .Ss Variables
168: The following variables are also defined:
169: .Bl -ohang -offset "XXXX"
170: .\" LIST-ITEM
171: .It Va man_macronames
172: An array of string-ified token names.
173: .El
174: .\" SUBSECTION
175: .Ss Abstract Syntax Tree
176: The
177: .Nm
178: functions produce an abstract syntax tree (AST) describing input in a
179: regular form. It may be reviewed at any time with
180: .Fn man_nodes ;
181: however, if called before
182: .Fn man_endparse ,
183: or after
184: .Fn man_endparse
185: or
186: .Fn man_parseln
187: fail, it may be incomplete.
188: .\" PARAGRAPH
189: .Pp
190: This AST is governed by the ontological
191: rules dictated in
192: .Xr man 7
193: and derives its terminology accordingly.
194: .\" PARAGRAPH
195: .Pp
196: The AST is composed of
197: .Vt struct man_node
198: nodes with element, root and text types as declared
199: by the
200: .Va type
201: field. Each node also provides its parse point (the
202: .Va line ,
203: .Va sec ,
204: and
205: .Va pos
206: fields), its position in the tree (the
207: .Va parent ,
208: .Va child ,
209: .Va next
210: and
211: .Va prev
212: fields) and some type-specific data.
213: .\" PARAGRAPH
214: .Pp
215: The tree itself is arranged according to the following normal form,
216: where capitalised non-terminals represent nodes.
217: .Pp
218: .Bl -tag -width "ELEMENTXX" -compact -offset "XXXX"
219: .\" LIST-ITEM
220: .It ROOT
221: \(<- mnode+
222: .It mnode
223: \(<- ELEMENT | TEXT
224: .It ELEMENT
225: \(<- ELEMENT | TEXT*
226: .It TEXT
227: \(<- [[:alpha:]]*
228: .El
229: .\" PARAGRAPH
230: .Pp
231: The only elements capable of nesting other elements are those with
232: next-lint scope as documented in
233: .Xr man 7 .
234: .\" SECTION
235: .Sh EXAMPLES
236: The following example reads lines from stdin and parses them, operating
237: on the finished parse tree with
238: .Fn parsed .
239: Note that, if the last line of the file isn't newline-terminated, this
240: will truncate the file's last character (see
241: .Xr fgetln 3 ) .
242: Further, this example does not error-check nor free memory upon failure.
243: .Bd -literal -offset "XXXX"
244: struct man *man;
245: struct man_node *node;
246: char *buf;
247: size_t len;
248: int line;
249:
250: line = 1;
251: man = man_alloc(NULL, 0, NULL);
252:
253: while ((buf = fgetln(fp, &len))) {
254: buf[len - 1] = '\\0';
255: if ( ! man_parseln(man, line, buf))
256: errx(1, "man_parseln");
257: line++;
258: }
259:
260: if ( ! man_endparse(man))
261: errx(1, "man_endparse");
262: if (NULL == (node = man_node(man)))
263: errx(1, "man_node");
264:
265: parsed(man, node);
266: man_free(man);
267: .Ed
268: .\" SECTION
269: .Sh SEE ALSO
270: .Xr mandoc 1 ,
271: .Xr man 7
272: .\" SECTION
273: .Sh AUTHORS
274: The
275: .Nm
276: utility was written by
277: .An Kristaps Dzonsons Aq kristaps@openbsd.org .
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