xref: /freebsd/lib/libc/regex/grot/split.c (revision b0d29bc47dba79f6f38e67eabadfb4b32ffd9390)
1 #include <sys/cdefs.h>
2 __FBSDID("$FreeBSD$");
3 
4 #include <stdio.h>
5 #include <string.h>
6 
7 #include "split.ih"
8 
9 /*
10  - split - divide a string into fields, like awk split()
11  == int split(char *string, char *fields[], int nfields, char *sep);
12  - fields: list is not NULL-terminated
13  - nfields: number of entries available in fields[]
14  - sep: "" white, "c" single char, "ab" [ab]+
15  */
16 int				/* number of fields, including overflow */
17 split(char *string, char *fields[], int nfields, char *sep)
18 {
19 	char *p = string;
20 	char c;			/* latest character */
21 	char sepc = sep[0];
22 	char sepc2;
23 	int fn;
24 	char **fp = fields;
25 	char *sepp;
26 	int trimtrail;
27 
28 	/* white space */
29 	if (sepc == '\0') {
30 		while ((c = *p++) == ' ' || c == '\t')
31 			continue;
32 		p--;
33 		trimtrail = 1;
34 		sep = " \t";	/* note, code below knows this is 2 long */
35 		sepc = ' ';
36 	} else
37 		trimtrail = 0;
38 	sepc2 = sep[1];		/* now we can safely pick this up */
39 
40 	/* catch empties */
41 	if (*p == '\0')
42 		return(0);
43 
44 	/* single separator */
45 	if (sepc2 == '\0') {
46 		fn = nfields;
47 		for (;;) {
48 			*fp++ = p;
49 			fn--;
50 			if (fn == 0)
51 				break;
52 			while ((c = *p++) != sepc)
53 				if (c == '\0')
54 					return(nfields - fn);
55 			*(p-1) = '\0';
56 		}
57 		/* we have overflowed the fields vector -- just count them */
58 		fn = nfields;
59 		for (;;) {
60 			while ((c = *p++) != sepc)
61 				if (c == '\0')
62 					return(fn);
63 			fn++;
64 		}
65 		/* not reached */
66 	}
67 
68 	/* two separators */
69 	if (sep[2] == '\0') {
70 		fn = nfields;
71 		for (;;) {
72 			*fp++ = p;
73 			fn--;
74 			while ((c = *p++) != sepc && c != sepc2)
75 				if (c == '\0') {
76 					if (trimtrail && **(fp-1) == '\0')
77 						fn++;
78 					return(nfields - fn);
79 				}
80 			if (fn == 0)
81 				break;
82 			*(p-1) = '\0';
83 			while ((c = *p++) == sepc || c == sepc2)
84 				continue;
85 			p--;
86 		}
87 		/* we have overflowed the fields vector -- just count them */
88 		fn = nfields;
89 		while (c != '\0') {
90 			while ((c = *p++) == sepc || c == sepc2)
91 				continue;
92 			p--;
93 			fn++;
94 			while ((c = *p++) != '\0' && c != sepc && c != sepc2)
95 				continue;
96 		}
97 		/* might have to trim trailing white space */
98 		if (trimtrail) {
99 			p--;
100 			while ((c = *--p) == sepc || c == sepc2)
101 				continue;
102 			p++;
103 			if (*p != '\0') {
104 				if (fn == nfields+1)
105 					*p = '\0';
106 				fn--;
107 			}
108 		}
109 		return(fn);
110 	}
111 
112 	/* n separators */
113 	fn = 0;
114 	for (;;) {
115 		if (fn < nfields)
116 			*fp++ = p;
117 		fn++;
118 		for (;;) {
119 			c = *p++;
120 			if (c == '\0')
121 				return(fn);
122 			sepp = sep;
123 			while ((sepc = *sepp++) != '\0' && sepc != c)
124 				continue;
125 			if (sepc != '\0')	/* it was a separator */
126 				break;
127 		}
128 		if (fn < nfields)
129 			*(p-1) = '\0';
130 		for (;;) {
131 			c = *p++;
132 			sepp = sep;
133 			while ((sepc = *sepp++) != '\0' && sepc != c)
134 				continue;
135 			if (sepc == '\0')	/* it wasn't a separator */
136 				break;
137 		}
138 		p--;
139 	}
140 
141 	/* not reached */
142 }
143 
144 #ifdef TEST_SPLIT
145 
146 
147 /*
148  * test program
149  * pgm		runs regression
150  * pgm sep	splits stdin lines by sep
151  * pgm str sep	splits str by sep
152  * pgm str sep n	splits str by sep n times
153  */
154 int
155 main(int argc, char *argv[])
156 {
157 	char buf[512];
158 	int n;
159 #	define	MNF	10
160 	char *fields[MNF];
161 
162 	if (argc > 4)
163 		for (n = atoi(argv[3]); n > 0; n--) {
164 			(void) strcpy(buf, argv[1]);
165 		}
166 	else if (argc > 3)
167 		for (n = atoi(argv[3]); n > 0; n--) {
168 			(void) strcpy(buf, argv[1]);
169 			(void) split(buf, fields, MNF, argv[2]);
170 		}
171 	else if (argc > 2)
172 		dosplit(argv[1], argv[2]);
173 	else if (argc > 1)
174 		while (fgets(buf, sizeof(buf), stdin) != NULL) {
175 			buf[strlen(buf)-1] = '\0';	/* stomp newline */
176 			dosplit(buf, argv[1]);
177 		}
178 	else
179 		regress();
180 
181 	exit(0);
182 }
183 
184 void
185 dosplit(char *string, char *seps)
186 {
187 #	define	NF	5
188 	char *fields[NF];
189 	int nf;
190 
191 	nf = split(string, fields, NF, seps);
192 	print(nf, NF, fields);
193 }
194 
195 void
196 print(int nf, int nfp, char *fields[])
197 {
198 	int fn;
199 	int bound;
200 
201 	bound = (nf > nfp) ? nfp : nf;
202 	printf("%d:\t", nf);
203 	for (fn = 0; fn < bound; fn++)
204 		printf("\"%s\"%s", fields[fn], (fn+1 < nf) ? ", " : "\n");
205 }
206 
207 #define	RNF	5		/* some table entries know this */
208 struct {
209 	char *str;
210 	char *seps;
211 	int nf;
212 	char *fi[RNF];
213 } tests[] = {
214 	"",		" ",	0,	{ "" },
215 	" ",		" ",	2,	{ "", "" },
216 	"x",		" ",	1,	{ "x" },
217 	"xy",		" ",	1,	{ "xy" },
218 	"x y",		" ",	2,	{ "x", "y" },
219 	"abc def  g ",	" ",	5,	{ "abc", "def", "", "g", "" },
220 	"  a bcd",	" ",	4,	{ "", "", "a", "bcd" },
221 	"a b c d e f",	" ",	6,	{ "a", "b", "c", "d", "e f" },
222 	" a b c d ",	" ",	6,	{ "", "a", "b", "c", "d " },
223 
224 	"",		" _",	0,	{ "" },
225 	" ",		" _",	2,	{ "", "" },
226 	"x",		" _",	1,	{ "x" },
227 	"x y",		" _",	2,	{ "x", "y" },
228 	"ab _ cd",	" _",	2,	{ "ab", "cd" },
229 	" a_b  c ",	" _",	5,	{ "", "a", "b", "c", "" },
230 	"a b c_d e f",	" _",	6,	{ "a", "b", "c", "d", "e f" },
231 	" a b c d ",	" _",	6,	{ "", "a", "b", "c", "d " },
232 
233 	"",		" _~",	0,	{ "" },
234 	" ",		" _~",	2,	{ "", "" },
235 	"x",		" _~",	1,	{ "x" },
236 	"x y",		" _~",	2,	{ "x", "y" },
237 	"ab _~ cd",	" _~",	2,	{ "ab", "cd" },
238 	" a_b  c~",	" _~",	5,	{ "", "a", "b", "c", "" },
239 	"a b_c d~e f",	" _~",	6,	{ "a", "b", "c", "d", "e f" },
240 	"~a b c d ",	" _~",	6,	{ "", "a", "b", "c", "d " },
241 
242 	"",		" _~-",	0,	{ "" },
243 	" ",		" _~-",	2,	{ "", "" },
244 	"x",		" _~-",	1,	{ "x" },
245 	"x y",		" _~-",	2,	{ "x", "y" },
246 	"ab _~- cd",	" _~-",	2,	{ "ab", "cd" },
247 	" a_b  c~",	" _~-",	5,	{ "", "a", "b", "c", "" },
248 	"a b_c-d~e f",	" _~-",	6,	{ "a", "b", "c", "d", "e f" },
249 	"~a-b c d ",	" _~-",	6,	{ "", "a", "b", "c", "d " },
250 
251 	"",		"  ",	0,	{ "" },
252 	" ",		"  ",	2,	{ "", "" },
253 	"x",		"  ",	1,	{ "x" },
254 	"xy",		"  ",	1,	{ "xy" },
255 	"x y",		"  ",	2,	{ "x", "y" },
256 	"abc def  g ",	"  ",	4,	{ "abc", "def", "g", "" },
257 	"  a bcd",	"  ",	3,	{ "", "a", "bcd" },
258 	"a b c d e f",	"  ",	6,	{ "a", "b", "c", "d", "e f" },
259 	" a b c d ",	"  ",	6,	{ "", "a", "b", "c", "d " },
260 
261 	"",		"",	0,	{ "" },
262 	" ",		"",	0,	{ "" },
263 	"x",		"",	1,	{ "x" },
264 	"xy",		"",	1,	{ "xy" },
265 	"x y",		"",	2,	{ "x", "y" },
266 	"abc def  g ",	"",	3,	{ "abc", "def", "g" },
267 	"\t a bcd",	"",	2,	{ "a", "bcd" },
268 	"  a \tb\t c ",	"",	3,	{ "a", "b", "c" },
269 	"a b c d e ",	"",	5,	{ "a", "b", "c", "d", "e" },
270 	"a b\tc d e f",	"",	6,	{ "a", "b", "c", "d", "e f" },
271 	" a b c d e f ",	"",	6,	{ "a", "b", "c", "d", "e f " },
272 
273 	NULL,		NULL,	0,	{ NULL },
274 };
275 
276 void
277 regress(void)
278 {
279 	char buf[512];
280 	int n;
281 	char *fields[RNF+1];
282 	int nf;
283 	int i;
284 	int printit;
285 	char *f;
286 
287 	for (n = 0; tests[n].str != NULL; n++) {
288 		(void) strcpy(buf, tests[n].str);
289 		fields[RNF] = NULL;
290 		nf = split(buf, fields, RNF, tests[n].seps);
291 		printit = 0;
292 		if (nf != tests[n].nf) {
293 			printf("split `%s' by `%s' gave %d fields, not %d\n",
294 				tests[n].str, tests[n].seps, nf, tests[n].nf);
295 			printit = 1;
296 		} else if (fields[RNF] != NULL) {
297 			printf("split() went beyond array end\n");
298 			printit = 1;
299 		} else {
300 			for (i = 0; i < nf && i < RNF; i++) {
301 				f = fields[i];
302 				if (f == NULL)
303 					f = "(NULL)";
304 				if (strcmp(f, tests[n].fi[i]) != 0) {
305 					printf("split `%s' by `%s' field %d is `%s', not `%s'\n",
306 						tests[n].str, tests[n].seps,
307 						i, fields[i], tests[n].fi[i]);
308 					printit = 1;
309 				}
310 			}
311 		}
312 		if (printit)
313 			print(nf, RNF, fields);
314 	}
315 }
316 #endif
317