1 /* vi: set sw=8 ts=8: */
3 * cut.c - minimalist version of cut
5 * Copyright (C) 1999,2000,2001 by Lineo, inc.
6 * Written by Mark Whitley <markw@lineo.com>, <markw@codepoet.org>
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * General Public License for more details.
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
34 static const char optstring[] = "b:c:f:d:sn";
35 #define OPT_BYTE_FLGS 1
36 #define OPT_CHAR_FLGS 2
37 #define OPT_FIELDS_FLGS 4
38 #define OPT_DELIM_FLGS 8
39 #define OPT_SUPRESS_FLGS 16
40 static char part; /* (b)yte, (c)har, (f)ields */
41 static unsigned int supress_non_delimited_lines;
42 static char delim = '\t'; /* delimiter, default is tab */
49 static const int BOL = 0;
50 static const int EOL = INT_MAX;
51 static const int NON_RANGE = -1;
53 static struct cut_list *cut_lists = NULL; /* growable array holding a series of lists */
54 static unsigned int nlists = 0; /* number of elements in above list */
57 static int cmpfunc(const void *a, const void *b)
59 struct cut_list *la = (struct cut_list *)a;
60 struct cut_list *lb = (struct cut_list *)b;
62 if (la->startpos > lb->startpos)
64 if (la->startpos < lb->startpos)
71 * parse_lists() - parses a list and puts values into startpos and endpos.
72 * valid list formats: N, N-, N-M, -M
73 * more than one list can be seperated by commas
75 static void parse_lists(char *lists)
82 /* take apart the lists, one by one (they are seperated with commas */
83 while ((ltok = strsep(&lists, ",")) != NULL) {
85 /* it's actually legal to pass an empty list */
86 if (strlen(ltok) == 0)
89 /* get the start pos */
90 ntok = strsep(<ok, "-");
92 fprintf(stderr, "Help ntok is null for starting position! What do I do?\n");
93 } else if (strlen(ntok) == 0) {
96 s = strtoul(ntok, &junk, 10);
97 if(*junk != '\0' || s < 0)
98 bb_error_msg_and_die("invalid byte or field list");
100 /* account for the fact that arrays are zero based, while the user
101 * expects the first char on the line to be char # 1 */
106 /* get the end pos */
107 ntok = strsep(<ok, "-");
110 } else if (strlen(ntok) == 0) {
113 e = strtoul(ntok, &junk, 10);
114 if(*junk != '\0' || e < 0)
115 bb_error_msg_and_die("invalid byte or field list");
116 /* if the user specified and end position of 0, that means "til the
120 e--; /* again, arrays are zero based, lines are 1 based */
125 /* if there's something left to tokenize, the user past an invalid list */
127 bb_error_msg_and_die("invalid byte or field list");
129 /* add the new list */
130 cut_lists = xrealloc(cut_lists, sizeof(struct cut_list) * (++nlists));
131 cut_lists[nlists-1].startpos = s;
132 cut_lists[nlists-1].endpos = e;
135 /* make sure we got some cut positions out of all that */
137 bb_error_msg_and_die("missing list of positions");
139 /* now that the lists are parsed, we need to sort them to make life easier
140 * on us when it comes time to print the chars / fields / lines */
141 qsort(cut_lists, nlists, sizeof(struct cut_list), cmpfunc);
146 static void cut_line_by_chars(const char *line)
149 /* set up a list so we can keep track of what's been printed */
150 char *printed = xcalloc(strlen(line), sizeof(char));
152 /* print the chars specified in each cut list */
153 for (c = 0; c < nlists; c++) {
154 l = cut_lists[c].startpos;
155 while (l < strlen(line)) {
161 if (cut_lists[c].endpos == NON_RANGE || l > cut_lists[c].endpos)
165 putchar('\n'); /* cuz we were handed a chomped line */
170 static void cut_line_by_fields(char *line)
173 int ndelim = -1; /* zero-based / one-based problem */
174 int nfields_printed = 0;
176 char d[2] = { delim, 0 };
179 /* test the easy case first: does this line contain any delimiters? */
180 if (strchr(line, delim) == NULL) {
181 if (!supress_non_delimited_lines)
186 /* set up a list so we can keep track of what's been printed */
187 printed = xcalloc(strlen(line), sizeof(char));
189 /* process each list on this line, for as long as we've got a line to process */
190 for (c = 0; c < nlists && line; c++) {
191 f = cut_lists[c].startpos;
194 /* find the field we're looking for */
195 while (line && ndelim < f) {
196 field = strsep(&line, d);
200 /* we found it, and it hasn't been printed yet */
201 if (field && ndelim == f && !printed[ndelim]) {
202 /* if this isn't our first time through, we need to print the
203 * delimiter after the last field that was printed */
204 if (nfields_printed > 0)
206 fputs(field, stdout);
207 printed[ndelim] = 'X';
213 /* keep going as long as we have a line to work with, this is a
214 * list, and we're not at the end of that list */
215 } while (line && cut_lists[c].endpos != NON_RANGE && f <= cut_lists[c].endpos);
218 /* if we printed anything at all, we need to finish it with a newline cuz
219 * we were handed a chomped line */
226 static void cut_file_by_lines(const char *line, unsigned int linenum)
231 /* I can't initialize this above cuz the "initializer isn't
232 * constant" *sigh* */
234 l = cut_lists[c].startpos;
236 /* get out if we have no more lists to process or if the lines are lower
237 * than what we're interested in */
238 if (c >= nlists || linenum < l)
241 /* if the line we're looking for is lower than the one we were passed, it
242 * means we displayed it already, so move on */
243 while (l < linenum) {
245 /* move on to the next list if we're at the end of this one */
246 if (cut_lists[c].endpos == NON_RANGE || l > cut_lists[c].endpos) {
248 /* get out if there's no more lists to process */
251 l = cut_lists[c].startpos;
252 /* get out if the current line is lower than the one we just became
259 /* If we made it here, it means we've found the line we're looking for, so print it */
267 static void cut_file(FILE *file)
270 unsigned int linenum = 0; /* keep these zero-based to be consistent */
272 /* go through every line in the file */
273 while ((line = bb_get_chomped_line_from_file(file)) != NULL) {
275 /* cut based on chars/bytes XXX: only works when sizeof(char) == byte */
276 if ((part & (OPT_CHAR_FLGS | OPT_BYTE_FLGS)))
277 cut_line_by_chars(line);
279 /* cut based on fields */
282 cut_file_by_lines(line, linenum);
284 cut_line_by_fields(line);
293 extern int cut_main(int argc, char **argv)
298 bb_opt_complementaly = "b~bcf:c~bcf:f~bcf";
299 opt = bb_getopt_ulflags(argc, argv, optstring, &sopt, &sopt, &sopt, &sdopt);
300 part = opt & (OPT_BYTE_FLGS|OPT_CHAR_FLGS|OPT_FIELDS_FLGS);
302 bb_error_msg_and_die("you must specify a list of bytes, characters, or fields");
303 if(opt & 0x80000000UL)
304 bb_error_msg_and_die("only one type of list may be specified");
306 if((opt & (OPT_DELIM_FLGS))) {
307 if (strlen(sdopt) > 1) {
308 bb_error_msg_and_die("the delimiter must be a single character");
312 supress_non_delimited_lines = opt & OPT_SUPRESS_FLGS;
314 /* non-field (char or byte) cutting has some special handling */
315 if (part != OPT_FIELDS_FLGS) {
316 if (supress_non_delimited_lines) {
317 bb_error_msg_and_die("suppressing non-delimited lines makes sense"
318 " only when operating on fields");
321 bb_error_msg_and_die("a delimiter may be specified only when operating on fields");
325 /* argv[(optind)..(argc-1)] should be names of file to process. If no
326 * files were specified or '-' was specified, take input from stdin.
327 * Otherwise, we process all the files specified. */
328 if (argv[optind] == NULL || (strcmp(argv[optind], "-") == 0)) {
334 for (i = optind; i < argc; i++) {
335 file = bb_wfopen(argv[i], "r");