xref: /freebsd/lib/libc/regex/grot/split.c (revision a2f733abcff64628b7771a47089628b7327a88bd)
1 #include <stdio.h>
2 #include <string.h>
3 
4 #include "split.ih"
5 
6 /*
7  - split - divide a string into fields, like awk split()
8  == int split(char *string, char *fields[], int nfields, char *sep);
9  - fields: list is not NULL-terminated
10  - nfields: number of entries available in fields[]
11  - sep: "" white, "c" single char, "ab" [ab]+
12  */
13 int				/* number of fields, including overflow */
14 split(char *string, char *fields[], int nfields, char *sep)
15 {
16 	char *p = string;
17 	char c;			/* latest character */
18 	char sepc = sep[0];
19 	char sepc2;
20 	int fn;
21 	char **fp = fields;
22 	char *sepp;
23 	int trimtrail;
24 
25 	/* white space */
26 	if (sepc == '\0') {
27 		while ((c = *p++) == ' ' || c == '\t')
28 			continue;
29 		p--;
30 		trimtrail = 1;
31 		sep = " \t";	/* note, code below knows this is 2 long */
32 		sepc = ' ';
33 	} else
34 		trimtrail = 0;
35 	sepc2 = sep[1];		/* now we can safely pick this up */
36 
37 	/* catch empties */
38 	if (*p == '\0')
39 		return(0);
40 
41 	/* single separator */
42 	if (sepc2 == '\0') {
43 		fn = nfields;
44 		for (;;) {
45 			*fp++ = p;
46 			fn--;
47 			if (fn == 0)
48 				break;
49 			while ((c = *p++) != sepc)
50 				if (c == '\0')
51 					return(nfields - fn);
52 			*(p-1) = '\0';
53 		}
54 		/* we have overflowed the fields vector -- just count them */
55 		fn = nfields;
56 		for (;;) {
57 			while ((c = *p++) != sepc)
58 				if (c == '\0')
59 					return(fn);
60 			fn++;
61 		}
62 		/* not reached */
63 	}
64 
65 	/* two separators */
66 	if (sep[2] == '\0') {
67 		fn = nfields;
68 		for (;;) {
69 			*fp++ = p;
70 			fn--;
71 			while ((c = *p++) != sepc && c != sepc2)
72 				if (c == '\0') {
73 					if (trimtrail && **(fp-1) == '\0')
74 						fn++;
75 					return(nfields - fn);
76 				}
77 			if (fn == 0)
78 				break;
79 			*(p-1) = '\0';
80 			while ((c = *p++) == sepc || c == sepc2)
81 				continue;
82 			p--;
83 		}
84 		/* we have overflowed the fields vector -- just count them */
85 		fn = nfields;
86 		while (c != '\0') {
87 			while ((c = *p++) == sepc || c == sepc2)
88 				continue;
89 			p--;
90 			fn++;
91 			while ((c = *p++) != '\0' && c != sepc && c != sepc2)
92 				continue;
93 		}
94 		/* might have to trim trailing white space */
95 		if (trimtrail) {
96 			p--;
97 			while ((c = *--p) == sepc || c == sepc2)
98 				continue;
99 			p++;
100 			if (*p != '\0') {
101 				if (fn == nfields+1)
102 					*p = '\0';
103 				fn--;
104 			}
105 		}
106 		return(fn);
107 	}
108 
109 	/* n separators */
110 	fn = 0;
111 	for (;;) {
112 		if (fn < nfields)
113 			*fp++ = p;
114 		fn++;
115 		for (;;) {
116 			c = *p++;
117 			if (c == '\0')
118 				return(fn);
119 			sepp = sep;
120 			while ((sepc = *sepp++) != '\0' && sepc != c)
121 				continue;
122 			if (sepc != '\0')	/* it was a separator */
123 				break;
124 		}
125 		if (fn < nfields)
126 			*(p-1) = '\0';
127 		for (;;) {
128 			c = *p++;
129 			sepp = sep;
130 			while ((sepc = *sepp++) != '\0' && sepc != c)
131 				continue;
132 			if (sepc == '\0')	/* it wasn't a separator */
133 				break;
134 		}
135 		p--;
136 	}
137 
138 	/* not reached */
139 }
140 
141 #ifdef TEST_SPLIT
142 
143 
144 /*
145  * test program
146  * pgm		runs regression
147  * pgm sep	splits stdin lines by sep
148  * pgm str sep	splits str by sep
149  * pgm str sep n	splits str by sep n times
150  */
151 int
152 main(int argc, char *argv[])
153 {
154 	char buf[512];
155 	int n;
156 #	define	MNF	10
157 	char *fields[MNF];
158 
159 	if (argc > 4)
160 		for (n = atoi(argv[3]); n > 0; n--) {
161 			(void) strcpy(buf, argv[1]);
162 		}
163 	else if (argc > 3)
164 		for (n = atoi(argv[3]); n > 0; n--) {
165 			(void) strcpy(buf, argv[1]);
166 			(void) split(buf, fields, MNF, argv[2]);
167 		}
168 	else if (argc > 2)
169 		dosplit(argv[1], argv[2]);
170 	else if (argc > 1)
171 		while (fgets(buf, sizeof(buf), stdin) != NULL) {
172 			buf[strlen(buf)-1] = '\0';	/* stomp newline */
173 			dosplit(buf, argv[1]);
174 		}
175 	else
176 		regress();
177 
178 	exit(0);
179 }
180 
181 void
182 dosplit(char *string, char *seps)
183 {
184 #	define	NF	5
185 	char *fields[NF];
186 	int nf;
187 
188 	nf = split(string, fields, NF, seps);
189 	print(nf, NF, fields);
190 }
191 
192 void
193 print(int nf, int nfp, char *fields[])
194 {
195 	int fn;
196 	int bound;
197 
198 	bound = (nf > nfp) ? nfp : nf;
199 	printf("%d:\t", nf);
200 	for (fn = 0; fn < bound; fn++)
201 		printf("\"%s\"%s", fields[fn], (fn+1 < nf) ? ", " : "\n");
202 }
203 
204 #define	RNF	5		/* some table entries know this */
205 struct {
206 	char *str;
207 	char *seps;
208 	int nf;
209 	char *fi[RNF];
210 } tests[] = {
211 	"",		" ",	0,	{ "" },
212 	" ",		" ",	2,	{ "", "" },
213 	"x",		" ",	1,	{ "x" },
214 	"xy",		" ",	1,	{ "xy" },
215 	"x y",		" ",	2,	{ "x", "y" },
216 	"abc def  g ",	" ",	5,	{ "abc", "def", "", "g", "" },
217 	"  a bcd",	" ",	4,	{ "", "", "a", "bcd" },
218 	"a b c d e f",	" ",	6,	{ "a", "b", "c", "d", "e f" },
219 	" a b c d ",	" ",	6,	{ "", "a", "b", "c", "d " },
220 
221 	"",		" _",	0,	{ "" },
222 	" ",		" _",	2,	{ "", "" },
223 	"x",		" _",	1,	{ "x" },
224 	"x y",		" _",	2,	{ "x", "y" },
225 	"ab _ cd",	" _",	2,	{ "ab", "cd" },
226 	" a_b  c ",	" _",	5,	{ "", "a", "b", "c", "" },
227 	"a b c_d e f",	" _",	6,	{ "a", "b", "c", "d", "e f" },
228 	" a b c d ",	" _",	6,	{ "", "a", "b", "c", "d " },
229 
230 	"",		" _~",	0,	{ "" },
231 	" ",		" _~",	2,	{ "", "" },
232 	"x",		" _~",	1,	{ "x" },
233 	"x y",		" _~",	2,	{ "x", "y" },
234 	"ab _~ cd",	" _~",	2,	{ "ab", "cd" },
235 	" a_b  c~",	" _~",	5,	{ "", "a", "b", "c", "" },
236 	"a b_c d~e f",	" _~",	6,	{ "a", "b", "c", "d", "e f" },
237 	"~a b c d ",	" _~",	6,	{ "", "a", "b", "c", "d " },
238 
239 	"",		" _~-",	0,	{ "" },
240 	" ",		" _~-",	2,	{ "", "" },
241 	"x",		" _~-",	1,	{ "x" },
242 	"x y",		" _~-",	2,	{ "x", "y" },
243 	"ab _~- cd",	" _~-",	2,	{ "ab", "cd" },
244 	" a_b  c~",	" _~-",	5,	{ "", "a", "b", "c", "" },
245 	"a b_c-d~e f",	" _~-",	6,	{ "a", "b", "c", "d", "e f" },
246 	"~a-b c d ",	" _~-",	6,	{ "", "a", "b", "c", "d " },
247 
248 	"",		"  ",	0,	{ "" },
249 	" ",		"  ",	2,	{ "", "" },
250 	"x",		"  ",	1,	{ "x" },
251 	"xy",		"  ",	1,	{ "xy" },
252 	"x y",		"  ",	2,	{ "x", "y" },
253 	"abc def  g ",	"  ",	4,	{ "abc", "def", "g", "" },
254 	"  a bcd",	"  ",	3,	{ "", "a", "bcd" },
255 	"a b c d e f",	"  ",	6,	{ "a", "b", "c", "d", "e f" },
256 	" a b c d ",	"  ",	6,	{ "", "a", "b", "c", "d " },
257 
258 	"",		"",	0,	{ "" },
259 	" ",		"",	0,	{ "" },
260 	"x",		"",	1,	{ "x" },
261 	"xy",		"",	1,	{ "xy" },
262 	"x y",		"",	2,	{ "x", "y" },
263 	"abc def  g ",	"",	3,	{ "abc", "def", "g" },
264 	"\t a bcd",	"",	2,	{ "a", "bcd" },
265 	"  a \tb\t c ",	"",	3,	{ "a", "b", "c" },
266 	"a b c d e ",	"",	5,	{ "a", "b", "c", "d", "e" },
267 	"a b\tc d e f",	"",	6,	{ "a", "b", "c", "d", "e f" },
268 	" a b c d e f ",	"",	6,	{ "a", "b", "c", "d", "e f " },
269 
270 	NULL,		NULL,	0,	{ NULL },
271 };
272 
273 void
274 regress(void)
275 {
276 	char buf[512];
277 	int n;
278 	char *fields[RNF+1];
279 	int nf;
280 	int i;
281 	int printit;
282 	char *f;
283 
284 	for (n = 0; tests[n].str != NULL; n++) {
285 		(void) strcpy(buf, tests[n].str);
286 		fields[RNF] = NULL;
287 		nf = split(buf, fields, RNF, tests[n].seps);
288 		printit = 0;
289 		if (nf != tests[n].nf) {
290 			printf("split `%s' by `%s' gave %d fields, not %d\n",
291 				tests[n].str, tests[n].seps, nf, tests[n].nf);
292 			printit = 1;
293 		} else if (fields[RNF] != NULL) {
294 			printf("split() went beyond array end\n");
295 			printit = 1;
296 		} else {
297 			for (i = 0; i < nf && i < RNF; i++) {
298 				f = fields[i];
299 				if (f == NULL)
300 					f = "(NULL)";
301 				if (strcmp(f, tests[n].fi[i]) != 0) {
302 					printf("split `%s' by `%s' field %d is `%s', not `%s'\n",
303 						tests[n].str, tests[n].seps,
304 						i, fields[i], tests[n].fi[i]);
305 					printit = 1;
306 				}
307 			}
308 		}
309 		if (printit)
310 			print(nf, RNF, fields);
311 	}
312 }
313 #endif
314