xref: /freebsd/lib/libfigpar/figpar.3 (revision f5147e312f43a9050468de539aeafa072caa1a60)
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25.\" $FreeBSD$
26.\"
27.Dd March 13, 2018
28.Dt FIGPAR 3
29.Os
30.Sh NAME
31.Nm figpar ,
32.Nm parse_config ,
33.Nm get_config_option
34.Nd configuration file parsing library
35.Sh LIBRARY
36.Lb libfigpar
37.Sh SYNOPSIS
38.In figpar.h
39.Ft int
40.Fo parse_config
41.Fa "struct figpar_config options[]"
42.Fa "const char *path"
43.Fa "int \*[lp]*unknown\*[rp]\*[lp]struct figpar_config *option"
44.Fa "uint32_t line"
45.Fa "char *directive"
46.Fa "char *value\*[rp]"
47.Fa "uint8_t processing_options"
48.Fc
49.Ft "struct figpar_config *"
50.Fo get_config_option
51.Fa "struct figpar_config options[]"
52.Fa "const char *directive"
53.Fc
54.In string_m.h
55.Ft int
56.Fo replaceall
57.Fa "char *source"
58.Fa "const char *find"
59.Fa "const char *replace"
60.Fc
61.Ft unsigned int
62.Fo strcount
63.Fa "const char *source"
64.Fa "const char *find"
65.Fc
66.Ft void
67.Fo strexpand
68.Fa "char *source"
69.Fc
70.Ft void
71.Fo strexpandnl
72.Fa "char *source"
73.Fc
74.Ft void
75.Fo strtolower
76.Fa "char *source"
77.Fc
78.Sh DESCRIPTION
79The
80.Nm
81library provides a light-weight,
82portable framework for parsing configuration
83files.
84The library uses
85.Xr open 2 ,
86.Xr read 2 ,
87and
88.Xr lseek 2
89within the file pointed to by
90.Fa path
91to find directives and values which are then made available to the application.
92.Pp
93Due to the fact that configuration files may have basic syntax differences,
94the library does not attempt to impose any structure on the data but instead
95provides raw data to a set of callback functions.
96These callback functions can in-turn initiate abort through their return value,
97allowing custom syntax validation during parsing.
98.Pp
99Configuration directives,
100types,
101and callback functions are provided through data structures defined in
102.In figpar.h :
103.Bd -literal -offset indent
104struct figpar_config {
105    enum figpar_cfgtype		type;		/* value type */
106    const char			*directive;	/* keyword */
107    union figpar_cfgvalue	value;		/* value */
108
109    /* Pointer to function used when directive is found */
110    int (*action)(struct figpar_config *option, uint32_t line,
111        char *directive, char *value);
112};
113
114enum figpar_cfgtype {
115    FIGPAR_TYPE_NONE      = 0x0000, /* directives with no value */
116    FIGPAR_TYPE_BOOL      = 0x0001, /* boolean */
117    FIGPAR_TYPE_INT       = 0x0002, /* signed 32 bit integer */
118    FIGPAR_TYPE_UINT      = 0x0004, /* unsigned 32 bit integer */
119    FIGPAR_TYPE_STR       = 0x0008, /* string pointer */
120    FIGPAR_TYPE_STRARRAY  = 0x0010, /* string array pointer */
121    FIGPAR_TYPE_DATA1     = 0x0020, /* void data type-1 (open) */
122    FIGPAR_TYPE_DATA2     = 0x0040, /* void data type-2 (open) */
123    FIGPAR_TYPE_DATA3     = 0x0080, /* void data type-3 (open) */
124    FIGPAR_TYPE_RESERVED1 = 0x0100, /* reserved data type-1 */
125    FIGPAR_TYPE_RESERVED2 = 0x0200, /* reserved data type-2 */
126    FIGPAR_TYPE_RESERVED3 = 0x0400, /* reserved data type-3 */
127};
128
129union figpar_cfgvalue {
130    void	*data;      /* Pointer to NUL-terminated string */
131    char	*str;       /* Pointer to NUL-terminated string */
132    char	**strarray; /* Pointer to an array of strings */
133    int32_t	num;        /* Signed 32-bit integer value */
134    uint32_t	u_num;      /* Unsigned 32-bit integer value */
135    uint32_t	boolean:1;  /* Boolean integer value (0 or 1) */
136};
137.Ed
138.Pp
139The
140.Fa processing_options
141argument to
142.Fn parse_config
143is a mask of bit fields which indicate various
144processing options.
145The possible flags are:
146.Bl -tag -width FIGPAR_BREAK_ON_SEMICOLON
147.It Dv FIGPAR_BREAK_ON_EQUALS
148An equals sign
149.Pq Ql Li =
150is normally considered part of the directive.
151This flag enables terminating the directive at the equals sign.
152Also makes equals sign optional and transient.
153.It Dv FIGPAR_BREAK_ON_SEMICOLON
154A semicolon
155.Pq Ql Li \;
156is normally considered part of the value.
157This flag enables terminating the value at the semicolon.
158Also allows multiple statements on a single line separated by semicolon.
159.It Dv FIGPAR_CASE_SENSITIVE
160Normally directives are matched case insensitively using
161.Xr fnmatch 3 .
162This flag enables directive matching to be case sensitive.
163.It Dv FIGPAR_REQUIRE_EQUALS
164If a directive is not followed by an equals,
165processing is aborted.
166.It Dv FIGPAR_STRICT_EQUALS
167Equals must be part of the directive to be considered a delimiter between
168directive and value.
169.El
170.Pp
171The
172.Fa options
173struct array pointer can be NULL and every directive will run the
174.Fn unknown
175function argument.
176.Pp
177The directive for each figpar_config item in the
178.Fn parse_config
179options argument is matched against each parsed directive using
180.Xr fnmatch 3
181until a match is found.
182If a match is found,
183the
184.Fn action
185function for that figpar_config directive is run with the line number,
186directive,
187and value.
188Otherwise if no match,
189the
190.Fn unknown
191function is run
192.Pq with the same arguments .
193.Pp
194If either
195.Fa action
196or
197.Fa unknown
198return non-zero,
199.Fn parse_config
200aborts reading the file and returns the error value to its caller.
201.Pp
202.Fn get_config_option
203traverses the options-array and returns the option that matches via
204.Xr strcmp 3 ,
205or if no match a pointer to a static dummy struct is returned
206.Pq whose values are all zero or NULL .
207.Pp
208The use of
209.Fa "struct figpar_config"
210is entirely optional as-is the use of
211.Fa "enum figpar_cfgtype"
212or
213.Fa "union figpar_cfgvalue" .
214For example,
215a NULL pointer can be passed to
216.Fn parse_config
217for the first argument while providing a simple
218.Fa unknown
219function based on
220.Xr queue 3
221that populates a singly-linked list of a struct containing the
222.Fa directive
223and
224.Fa value .
225.Pp
226In addition,
227miscellaneous string manipulation routines are provided by
228.In string_m.h :
229.Bl -tag -width strexpandnl()
230.It Fn replaceall
231Replace all occurrences of
232.Fa find
233in
234.Fa source
235with
236.Fa replace .
237.It Fn strcount
238Count the number of occurrences of one string that appear in the
239.Fa source
240string.
241Return value is the total count.
242An example use would be to show how large a block of memory needs to be for a
243.Fn replaceall
244series.
245.It Fn strexpand
246Expand escape sequences in a buffer pointed to by
247.Fa source .
248.It Fn strexpandnl
249Expand only the escaped newlines in a buffer pointed to by
250.Fa source .
251.It Fn strtolower
252Convert a string to lower case.
253.El
254.Sh SEE ALSO
255.Xr queue 3
256.Sh HISTORY
257The
258.Nm
259library first appeared in
260.Fx 10.2 .
261.Sh AUTHORS
262.An Devin Teske Aq dteske@FreeBSD.org
263.Sh BUGS
264This is the first implementation of the library,
265and the interface may be subject to refinement.
266