xref: /freebsd/lib/libc/regex/grot/split.c (revision fcb560670601b2a4d87bb31d7531c8dcc37ee71b)
1 #include <sys/cdefs.h>
2 __FBSDID("$FreeBSD$");
3 
4 #include <stdio.h>
5 #include <string.h>
6 
7 /*
8  - split - divide a string into fields, like awk split()
9  = int split(char *string, char *fields[], int nfields, char *sep);
10  */
11 int				/* number of fields, including overflow */
12 split(string, fields, nfields, sep)
13 char *string;
14 char *fields[];			/* list is not NULL-terminated */
15 int nfields;			/* number of entries available in fields[] */
16 char *sep;			/* "" white, "c" single char, "ab" [ab]+ */
17 {
18 	char *p = string;
19 	char c;			/* latest character */
20 	char sepc = sep[0];
21 	char sepc2;
22 	int fn;
23 	char **fp = fields;
24 	char *sepp;
25 	int trimtrail;
26 
27 	/* white space */
28 	if (sepc == '\0') {
29 		while ((c = *p++) == ' ' || c == '\t')
30 			continue;
31 		p--;
32 		trimtrail = 1;
33 		sep = " \t";	/* note, code below knows this is 2 long */
34 		sepc = ' ';
35 	} else
36 		trimtrail = 0;
37 	sepc2 = sep[1];		/* now we can safely pick this up */
38 
39 	/* catch empties */
40 	if (*p == '\0')
41 		return(0);
42 
43 	/* single separator */
44 	if (sepc2 == '\0') {
45 		fn = nfields;
46 		for (;;) {
47 			*fp++ = p;
48 			fn--;
49 			if (fn == 0)
50 				break;
51 			while ((c = *p++) != sepc)
52 				if (c == '\0')
53 					return(nfields - fn);
54 			*(p-1) = '\0';
55 		}
56 		/* we have overflowed the fields vector -- just count them */
57 		fn = nfields;
58 		for (;;) {
59 			while ((c = *p++) != sepc)
60 				if (c == '\0')
61 					return(fn);
62 			fn++;
63 		}
64 		/* not reached */
65 	}
66 
67 	/* two separators */
68 	if (sep[2] == '\0') {
69 		fn = nfields;
70 		for (;;) {
71 			*fp++ = p;
72 			fn--;
73 			while ((c = *p++) != sepc && c != sepc2)
74 				if (c == '\0') {
75 					if (trimtrail && **(fp-1) == '\0')
76 						fn++;
77 					return(nfields - fn);
78 				}
79 			if (fn == 0)
80 				break;
81 			*(p-1) = '\0';
82 			while ((c = *p++) == sepc || c == sepc2)
83 				continue;
84 			p--;
85 		}
86 		/* we have overflowed the fields vector -- just count them */
87 		fn = nfields;
88 		while (c != '\0') {
89 			while ((c = *p++) == sepc || c == sepc2)
90 				continue;
91 			p--;
92 			fn++;
93 			while ((c = *p++) != '\0' && c != sepc && c != sepc2)
94 				continue;
95 		}
96 		/* might have to trim trailing white space */
97 		if (trimtrail) {
98 			p--;
99 			while ((c = *--p) == sepc || c == sepc2)
100 				continue;
101 			p++;
102 			if (*p != '\0') {
103 				if (fn == nfields+1)
104 					*p = '\0';
105 				fn--;
106 			}
107 		}
108 		return(fn);
109 	}
110 
111 	/* n separators */
112 	fn = 0;
113 	for (;;) {
114 		if (fn < nfields)
115 			*fp++ = p;
116 		fn++;
117 		for (;;) {
118 			c = *p++;
119 			if (c == '\0')
120 				return(fn);
121 			sepp = sep;
122 			while ((sepc = *sepp++) != '\0' && sepc != c)
123 				continue;
124 			if (sepc != '\0')	/* it was a separator */
125 				break;
126 		}
127 		if (fn < nfields)
128 			*(p-1) = '\0';
129 		for (;;) {
130 			c = *p++;
131 			sepp = sep;
132 			while ((sepc = *sepp++) != '\0' && sepc != c)
133 				continue;
134 			if (sepc == '\0')	/* it wasn't a separator */
135 				break;
136 		}
137 		p--;
138 	}
139 
140 	/* not reached */
141 }
142 
143 #ifdef TEST_SPLIT
144 
145 
146 /*
147  * test program
148  * pgm		runs regression
149  * pgm sep	splits stdin lines by sep
150  * pgm str sep	splits str by sep
151  * pgm str sep n	splits str by sep n times
152  */
153 int
154 main(argc, argv)
155 int argc;
156 char *argv[];
157 {
158 	char buf[512];
159 	int n;
160 #	define	MNF	10
161 	char *fields[MNF];
162 
163 	if (argc > 4)
164 		for (n = atoi(argv[3]); n > 0; n--) {
165 			(void) strcpy(buf, argv[1]);
166 		}
167 	else if (argc > 3)
168 		for (n = atoi(argv[3]); n > 0; n--) {
169 			(void) strcpy(buf, argv[1]);
170 			(void) split(buf, fields, MNF, argv[2]);
171 		}
172 	else if (argc > 2)
173 		dosplit(argv[1], argv[2]);
174 	else if (argc > 1)
175 		while (fgets(buf, sizeof(buf), stdin) != NULL) {
176 			buf[strlen(buf)-1] = '\0';	/* stomp newline */
177 			dosplit(buf, argv[1]);
178 		}
179 	else
180 		regress();
181 
182 	exit(0);
183 }
184 
185 dosplit(string, seps)
186 char *string;
187 char *seps;
188 {
189 #	define	NF	5
190 	char *fields[NF];
191 	int nf;
192 
193 	nf = split(string, fields, NF, seps);
194 	print(nf, NF, fields);
195 }
196 
197 print(nf, nfp, fields)
198 int nf;
199 int nfp;
200 char *fields[];
201 {
202 	int fn;
203 	int bound;
204 
205 	bound = (nf > nfp) ? nfp : nf;
206 	printf("%d:\t", nf);
207 	for (fn = 0; fn < bound; fn++)
208 		printf("\"%s\"%s", fields[fn], (fn+1 < nf) ? ", " : "\n");
209 }
210 
211 #define	RNF	5		/* some table entries know this */
212 struct {
213 	char *str;
214 	char *seps;
215 	int nf;
216 	char *fi[RNF];
217 } tests[] = {
218 	"",		" ",	0,	{ "" },
219 	" ",		" ",	2,	{ "", "" },
220 	"x",		" ",	1,	{ "x" },
221 	"xy",		" ",	1,	{ "xy" },
222 	"x y",		" ",	2,	{ "x", "y" },
223 	"abc def  g ",	" ",	5,	{ "abc", "def", "", "g", "" },
224 	"  a bcd",	" ",	4,	{ "", "", "a", "bcd" },
225 	"a b c d e f",	" ",	6,	{ "a", "b", "c", "d", "e f" },
226 	" a b c d ",	" ",	6,	{ "", "a", "b", "c", "d " },
227 
228 	"",		" _",	0,	{ "" },
229 	" ",		" _",	2,	{ "", "" },
230 	"x",		" _",	1,	{ "x" },
231 	"x y",		" _",	2,	{ "x", "y" },
232 	"ab _ cd",	" _",	2,	{ "ab", "cd" },
233 	" a_b  c ",	" _",	5,	{ "", "a", "b", "c", "" },
234 	"a b c_d e f",	" _",	6,	{ "a", "b", "c", "d", "e f" },
235 	" a b c d ",	" _",	6,	{ "", "a", "b", "c", "d " },
236 
237 	"",		" _~",	0,	{ "" },
238 	" ",		" _~",	2,	{ "", "" },
239 	"x",		" _~",	1,	{ "x" },
240 	"x y",		" _~",	2,	{ "x", "y" },
241 	"ab _~ cd",	" _~",	2,	{ "ab", "cd" },
242 	" a_b  c~",	" _~",	5,	{ "", "a", "b", "c", "" },
243 	"a b_c d~e f",	" _~",	6,	{ "a", "b", "c", "d", "e f" },
244 	"~a b c d ",	" _~",	6,	{ "", "a", "b", "c", "d " },
245 
246 	"",		" _~-",	0,	{ "" },
247 	" ",		" _~-",	2,	{ "", "" },
248 	"x",		" _~-",	1,	{ "x" },
249 	"x y",		" _~-",	2,	{ "x", "y" },
250 	"ab _~- cd",	" _~-",	2,	{ "ab", "cd" },
251 	" a_b  c~",	" _~-",	5,	{ "", "a", "b", "c", "" },
252 	"a b_c-d~e f",	" _~-",	6,	{ "a", "b", "c", "d", "e f" },
253 	"~a-b c d ",	" _~-",	6,	{ "", "a", "b", "c", "d " },
254 
255 	"",		"  ",	0,	{ "" },
256 	" ",		"  ",	2,	{ "", "" },
257 	"x",		"  ",	1,	{ "x" },
258 	"xy",		"  ",	1,	{ "xy" },
259 	"x y",		"  ",	2,	{ "x", "y" },
260 	"abc def  g ",	"  ",	4,	{ "abc", "def", "g", "" },
261 	"  a bcd",	"  ",	3,	{ "", "a", "bcd" },
262 	"a b c d e f",	"  ",	6,	{ "a", "b", "c", "d", "e f" },
263 	" a b c d ",	"  ",	6,	{ "", "a", "b", "c", "d " },
264 
265 	"",		"",	0,	{ "" },
266 	" ",		"",	0,	{ "" },
267 	"x",		"",	1,	{ "x" },
268 	"xy",		"",	1,	{ "xy" },
269 	"x y",		"",	2,	{ "x", "y" },
270 	"abc def  g ",	"",	3,	{ "abc", "def", "g" },
271 	"\t a bcd",	"",	2,	{ "a", "bcd" },
272 	"  a \tb\t c ",	"",	3,	{ "a", "b", "c" },
273 	"a b c d e ",	"",	5,	{ "a", "b", "c", "d", "e" },
274 	"a b\tc d e f",	"",	6,	{ "a", "b", "c", "d", "e f" },
275 	" a b c d e f ",	"",	6,	{ "a", "b", "c", "d", "e f " },
276 
277 	NULL,		NULL,	0,	{ NULL },
278 };
279 
280 regress()
281 {
282 	char buf[512];
283 	int n;
284 	char *fields[RNF+1];
285 	int nf;
286 	int i;
287 	int printit;
288 	char *f;
289 
290 	for (n = 0; tests[n].str != NULL; n++) {
291 		(void) strcpy(buf, tests[n].str);
292 		fields[RNF] = NULL;
293 		nf = split(buf, fields, RNF, tests[n].seps);
294 		printit = 0;
295 		if (nf != tests[n].nf) {
296 			printf("split `%s' by `%s' gave %d fields, not %d\n",
297 				tests[n].str, tests[n].seps, nf, tests[n].nf);
298 			printit = 1;
299 		} else if (fields[RNF] != NULL) {
300 			printf("split() went beyond array end\n");
301 			printit = 1;
302 		} else {
303 			for (i = 0; i < nf && i < RNF; i++) {
304 				f = fields[i];
305 				if (f == NULL)
306 					f = "(NULL)";
307 				if (strcmp(f, tests[n].fi[i]) != 0) {
308 					printf("split `%s' by `%s' field %d is `%s', not `%s'\n",
309 						tests[n].str, tests[n].seps,
310 						i, fields[i], tests[n].fi[i]);
311 					printit = 1;
312 				}
313 			}
314 		}
315 		if (printit)
316 			print(nf, RNF, fields);
317 	}
318 }
319 #endif
320