xref: /freebsd/lib/libc/regex/grot/split.c (revision 5521ff5a4d1929056e7ffc982fac3341ca54df7c)
1 /* $FreeBSD$
2  */
3 #include <stdio.h>
4 #include <string.h>
5 
6 /*
7  - split - divide a string into fields, like awk split()
8  = int split(char *string, char *fields[], int nfields, char *sep);
9  */
10 int				/* number of fields, including overflow */
11 split(string, fields, nfields, sep)
12 char *string;
13 char *fields[];			/* list is not NULL-terminated */
14 int nfields;			/* number of entries available in fields[] */
15 char *sep;			/* "" white, "c" single char, "ab" [ab]+ */
16 {
17 	register char *p = string;
18 	register char c;			/* latest character */
19 	register char sepc = sep[0];
20 	register char sepc2;
21 	register int fn;
22 	register char **fp = fields;
23 	register char *sepp;
24 	register int trimtrail;
25 
26 	/* white space */
27 	if (sepc == '\0') {
28 		while ((c = *p++) == ' ' || c == '\t')
29 			continue;
30 		p--;
31 		trimtrail = 1;
32 		sep = " \t";	/* note, code below knows this is 2 long */
33 		sepc = ' ';
34 	} else
35 		trimtrail = 0;
36 	sepc2 = sep[1];		/* now we can safely pick this up */
37 
38 	/* catch empties */
39 	if (*p == '\0')
40 		return(0);
41 
42 	/* single separator */
43 	if (sepc2 == '\0') {
44 		fn = nfields;
45 		for (;;) {
46 			*fp++ = p;
47 			fn--;
48 			if (fn == 0)
49 				break;
50 			while ((c = *p++) != sepc)
51 				if (c == '\0')
52 					return(nfields - fn);
53 			*(p-1) = '\0';
54 		}
55 		/* we have overflowed the fields vector -- just count them */
56 		fn = nfields;
57 		for (;;) {
58 			while ((c = *p++) != sepc)
59 				if (c == '\0')
60 					return(fn);
61 			fn++;
62 		}
63 		/* not reached */
64 	}
65 
66 	/* two separators */
67 	if (sep[2] == '\0') {
68 		fn = nfields;
69 		for (;;) {
70 			*fp++ = p;
71 			fn--;
72 			while ((c = *p++) != sepc && c != sepc2)
73 				if (c == '\0') {
74 					if (trimtrail && **(fp-1) == '\0')
75 						fn++;
76 					return(nfields - fn);
77 				}
78 			if (fn == 0)
79 				break;
80 			*(p-1) = '\0';
81 			while ((c = *p++) == sepc || c == sepc2)
82 				continue;
83 			p--;
84 		}
85 		/* we have overflowed the fields vector -- just count them */
86 		fn = nfields;
87 		while (c != '\0') {
88 			while ((c = *p++) == sepc || c == sepc2)
89 				continue;
90 			p--;
91 			fn++;
92 			while ((c = *p++) != '\0' && c != sepc && c != sepc2)
93 				continue;
94 		}
95 		/* might have to trim trailing white space */
96 		if (trimtrail) {
97 			p--;
98 			while ((c = *--p) == sepc || c == sepc2)
99 				continue;
100 			p++;
101 			if (*p != '\0') {
102 				if (fn == nfields+1)
103 					*p = '\0';
104 				fn--;
105 			}
106 		}
107 		return(fn);
108 	}
109 
110 	/* n separators */
111 	fn = 0;
112 	for (;;) {
113 		if (fn < nfields)
114 			*fp++ = p;
115 		fn++;
116 		for (;;) {
117 			c = *p++;
118 			if (c == '\0')
119 				return(fn);
120 			sepp = sep;
121 			while ((sepc = *sepp++) != '\0' && sepc != c)
122 				continue;
123 			if (sepc != '\0')	/* it was a separator */
124 				break;
125 		}
126 		if (fn < nfields)
127 			*(p-1) = '\0';
128 		for (;;) {
129 			c = *p++;
130 			sepp = sep;
131 			while ((sepc = *sepp++) != '\0' && sepc != c)
132 				continue;
133 			if (sepc == '\0')	/* it wasn't a separator */
134 				break;
135 		}
136 		p--;
137 	}
138 
139 	/* not reached */
140 }
141 
142 #ifdef TEST_SPLIT
143 
144 
145 /*
146  * test program
147  * pgm		runs regression
148  * pgm sep	splits stdin lines by sep
149  * pgm str sep	splits str by sep
150  * pgm str sep n	splits str by sep n times
151  */
152 int
153 main(argc, argv)
154 int argc;
155 char *argv[];
156 {
157 	char buf[512];
158 	register 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 dosplit(string, seps)
185 char *string;
186 char *seps;
187 {
188 #	define	NF	5
189 	char *fields[NF];
190 	register int nf;
191 
192 	nf = split(string, fields, NF, seps);
193 	print(nf, NF, fields);
194 }
195 
196 print(nf, nfp, fields)
197 int nf;
198 int nfp;
199 char *fields[];
200 {
201 	register int fn;
202 	register int bound;
203 
204 	bound = (nf > nfp) ? nfp : nf;
205 	printf("%d:\t", nf);
206 	for (fn = 0; fn < bound; fn++)
207 		printf("\"%s\"%s", fields[fn], (fn+1 < nf) ? ", " : "\n");
208 }
209 
210 #define	RNF	5		/* some table entries know this */
211 struct {
212 	char *str;
213 	char *seps;
214 	int nf;
215 	char *fi[RNF];
216 } tests[] = {
217 	"",		" ",	0,	{ "" },
218 	" ",		" ",	2,	{ "", "" },
219 	"x",		" ",	1,	{ "x" },
220 	"xy",		" ",	1,	{ "xy" },
221 	"x y",		" ",	2,	{ "x", "y" },
222 	"abc def  g ",	" ",	5,	{ "abc", "def", "", "g", "" },
223 	"  a bcd",	" ",	4,	{ "", "", "a", "bcd" },
224 	"a b c d e f",	" ",	6,	{ "a", "b", "c", "d", "e f" },
225 	" a b c d ",	" ",	6,	{ "", "a", "b", "c", "d " },
226 
227 	"",		" _",	0,	{ "" },
228 	" ",		" _",	2,	{ "", "" },
229 	"x",		" _",	1,	{ "x" },
230 	"x y",		" _",	2,	{ "x", "y" },
231 	"ab _ cd",	" _",	2,	{ "ab", "cd" },
232 	" a_b  c ",	" _",	5,	{ "", "a", "b", "c", "" },
233 	"a b c_d e f",	" _",	6,	{ "a", "b", "c", "d", "e f" },
234 	" a b c d ",	" _",	6,	{ "", "a", "b", "c", "d " },
235 
236 	"",		" _~",	0,	{ "" },
237 	" ",		" _~",	2,	{ "", "" },
238 	"x",		" _~",	1,	{ "x" },
239 	"x y",		" _~",	2,	{ "x", "y" },
240 	"ab _~ cd",	" _~",	2,	{ "ab", "cd" },
241 	" a_b  c~",	" _~",	5,	{ "", "a", "b", "c", "" },
242 	"a b_c d~e f",	" _~",	6,	{ "a", "b", "c", "d", "e f" },
243 	"~a b c d ",	" _~",	6,	{ "", "a", "b", "c", "d " },
244 
245 	"",		" _~-",	0,	{ "" },
246 	" ",		" _~-",	2,	{ "", "" },
247 	"x",		" _~-",	1,	{ "x" },
248 	"x y",		" _~-",	2,	{ "x", "y" },
249 	"ab _~- cd",	" _~-",	2,	{ "ab", "cd" },
250 	" a_b  c~",	" _~-",	5,	{ "", "a", "b", "c", "" },
251 	"a b_c-d~e f",	" _~-",	6,	{ "a", "b", "c", "d", "e f" },
252 	"~a-b c d ",	" _~-",	6,	{ "", "a", "b", "c", "d " },
253 
254 	"",		"  ",	0,	{ "" },
255 	" ",		"  ",	2,	{ "", "" },
256 	"x",		"  ",	1,	{ "x" },
257 	"xy",		"  ",	1,	{ "xy" },
258 	"x y",		"  ",	2,	{ "x", "y" },
259 	"abc def  g ",	"  ",	4,	{ "abc", "def", "g", "" },
260 	"  a bcd",	"  ",	3,	{ "", "a", "bcd" },
261 	"a b c d e f",	"  ",	6,	{ "a", "b", "c", "d", "e f" },
262 	" a b c d ",	"  ",	6,	{ "", "a", "b", "c", "d " },
263 
264 	"",		"",	0,	{ "" },
265 	" ",		"",	0,	{ "" },
266 	"x",		"",	1,	{ "x" },
267 	"xy",		"",	1,	{ "xy" },
268 	"x y",		"",	2,	{ "x", "y" },
269 	"abc def  g ",	"",	3,	{ "abc", "def", "g" },
270 	"\t a bcd",	"",	2,	{ "a", "bcd" },
271 	"  a \tb\t c ",	"",	3,	{ "a", "b", "c" },
272 	"a b c d e ",	"",	5,	{ "a", "b", "c", "d", "e" },
273 	"a b\tc d e f",	"",	6,	{ "a", "b", "c", "d", "e f" },
274 	" a b c d e f ",	"",	6,	{ "a", "b", "c", "d", "e f " },
275 
276 	NULL,		NULL,	0,	{ NULL },
277 };
278 
279 regress()
280 {
281 	char buf[512];
282 	register int n;
283 	char *fields[RNF+1];
284 	register int nf;
285 	register int i;
286 	register int printit;
287 	register char *f;
288 
289 	for (n = 0; tests[n].str != NULL; n++) {
290 		(void) strcpy(buf, tests[n].str);
291 		fields[RNF] = NULL;
292 		nf = split(buf, fields, RNF, tests[n].seps);
293 		printit = 0;
294 		if (nf != tests[n].nf) {
295 			printf("split `%s' by `%s' gave %d fields, not %d\n",
296 				tests[n].str, tests[n].seps, nf, tests[n].nf);
297 			printit = 1;
298 		} else if (fields[RNF] != NULL) {
299 			printf("split() went beyond array end\n");
300 			printit = 1;
301 		} else {
302 			for (i = 0; i < nf && i < RNF; i++) {
303 				f = fields[i];
304 				if (f == NULL)
305 					f = "(NULL)";
306 				if (strcmp(f, tests[n].fi[i]) != 0) {
307 					printf("split `%s' by `%s' field %d is `%s', not `%s'\n",
308 						tests[n].str, tests[n].seps,
309 						i, fields[i], tests[n].fi[i]);
310 					printit = 1;
311 				}
312 			}
313 		}
314 		if (printit)
315 			print(nf, RNF, fields);
316 	}
317 }
318 #endif
319