xref: /netbsd-src/share/man/man9/strlist.9 (revision af4f4aa1085d157fa54dfc3f390c439b5858461e)
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30.Dd January 20, 2021
31.Dt OFSL 9
32.Os
33.Sh NAME
34.Nm strlist ,
35.Nm strlist_next ,
36.Nm strlist_count ,
37.Nm strlist_string ,
38.Nm strlist_match ,
39.Nm strlist_index ,
40.Nm strlist_append
41.Nd functions to interact with OpenFirmware-style string lists
42.Sh SYNOPSIS
43.In sys/systm.h
44.Ft const char *
45.Fn strlist_next "const char *sl" "size_t slsize" "size_t *cursorp"
46.Ft void
47.Fn strlist_count "const char *sl" "size_t slsize"
48.Ft const char *
49.Fn strlist_string "const char *sl" "size_t slsize" "unsigned int index"
50.Ft int
51.Fn strlist_match "const char *sl" "size_t slsize" "const char *str"
52.Ft int
53.Fn strlist_pmatch "const char *sl" "size_t slsize" "const char *pattern"
54.Ft int
55.Fn strlist_index "const char *sl" "size_t slsize" "const char *str"
56.Ft bool
57.Fn strlist_append "char **slp" "size_t *slsizep" "const char *str"
58.Sh DESCRIPTION
59The
60.Nm
61functions provide a simple way to interact with OpenFirmware
62.Pq IEEE 1275
63string lists.
64.Pp
65An OpenFirmware string list is simply a buffer containing one or more
66NUL-terminated strings concatenated together.
67For example, a string list containing the strings
68.Dq foo ,
69.Dq bar ,
70and
71.Dq baz
72would be represented in memory as:
73.Bd -literal -offset indent
74foo\\0bar\\0baz\\0
75.Ed
76.Pp
77The following functions are available:
78.Bl -tag -width "xxxxx"
79.It Fn strlist_next "const char *sl" "size_t slsize" "size_t *cursorp"
80This function provides a way to enumerate the strings in a string list.
81To enumerate a string list, initialize
82.Fa cursor
83to 0 and pass it by reference to
84.Fn strlist_next .
85Each call to
86.Fn strlist_next
87returns the current string and advances the cursor to the next string in
88the list.
89If all strings in the list have been enumerated,
90.Fn strlist_next
91will return
92.Dv NULL .
93.It Fn strlist_count "const char *sl" "size_t slsize"
94Returns the number of strings in the string list.
95.It Fn strlist_string "const char *sl" "size_t slsize" "unsigned int index"
96Returns a pointer to the string in the string list at the specified
97index or
98.Dv NULL
99if the index is out of range.
100.It Fn strlist_match "const char *sl" "size_t slsize" "const char *str"
101Returns a weighted match value if the specified string appears in
102the string list.
103The value returned is the number of strings in the string list
104minus the index of the matched string.
105For example, if a string list contains the strings
106.Dq foo ,
107.Dq bar ,
108and
109.Dq baz ,
110a match against
111.Dq foo
112returns 3 and a match against
113.Dq baz
114returns 1.
115If the string does not appear in the string list, 0 is returned.
116.It Fn strlist_pmatch "const char *sl" "size_t slsize" "const char *pattern"
117Like
118.Fn strlist_match ,
119but uses
120.Fn pmatch
121to compare strings, allowing for wildcard characters to be specified in
122.Fa pattern .
123.It Fn strlist_index "const char *sl" "size_t slsize" "const char *str"
124Returns the index of the specified string if it appears in the
125string list, or \-1 if the string does not appear in the string list.
126.It Fn strlist_append "char **slp" "size_t *slsizep" "const char *str"
127Appends a copy of the specified string to the stringlist.
128Begin by initializing
129.Fa sl
130to
131.Dv NULL
132and
133.Fa slsize
134to 0.
135Pass these by reference to
136.Fn strlist_append .
137New memory for the string list will be allocated as needed.
138The resulting string list can be freed with
139.Fn kmem_free .
140Returns
141.Dv true
142if the string was successfully appended to the string list or
143.Dv false
144if memory allocation fails.
145.El
146.Sh EXAMPLES
147The following shows an example of string list enumeration using
148.Fn strlist_next :
149.Bd -literal
150void
151print_stringlist(const char *sl, size_t slsize)
152{
153	const char *cp;
154	size_t cursor;
155
156	printf("There are %u strings in the string list:\\n",
157	    strlist_count(sl, slsize));
158	for (cursor = 0;
159	     (cp = strlist_next(sl, slsize, &cursor) != NULL; ) {
160		printf("\\t%s\\n", cp);
161	}
162}
163.Ed
164.Pp
165The following example shows a simple way to use
166.Fn strlist_match :
167.Bd -literal
168bool
169is_compatible(int phandle, const char *compat_str)
170{
171	char buf[128];
172	int proplen;
173
174	proplen = OF_getprop(phandle, "compatible", buf, sizeof(buf));
175	return strlist_match(buf, proplen, compat_str) != 0;
176}
177.Ed
178.Pp
179The following example shows a use of
180.Fn strlist_pmatch :
181.Bd -literal
182bool
183is_pc_printer_port(const char *pnp_id_list, size_t list_size)
184{
185	return strlist_pmatch(pnp_id_list, list_size, "PNP04??") != 0;
186}
187.Ed
188.Pp
189The following example converts an array of strings to a string list using
190.Fn strlist_append :
191.Bd -literal
192char *
193string_array_to_string_list(const char **array, int count,
194    size_t *slsizep)
195{
196	char *sl;
197	size_t slsize;
198	int i;
199
200	for (i = 0, sl = NULL, slsize = 0; i < count; i++) {
201		if (!strlist_append(&sl, &slsize, array[i])) {
202			kmem_free(sl, slsize);
203			return NULL;
204		}
205	}
206
207	*slsizep = slsize;
208	return sl;
209}
210.Ed
211.Sh SEE ALSO
212.Xr kmem 9 ,
213.Xr pmatch 9
214.Sh HISTORY
215The
216.Nm
217functions first appeared in
218.Nx 10.0 .
219