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@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
33 static const char optstring[] = "b:c:f:d:sn";
34 #define OPT_BYTE_FLGS 1
35 #define OPT_CHAR_FLGS 2
36 #define OPT_FIELDS_FLGS 4
37 #define OPT_DELIM_FLGS 8
38 #define OPT_SUPRESS_FLGS 16
39 static char part; /* (b)yte, (c)har, (f)ields */
40 static unsigned int supress_non_delimited_lines;
41 static char delim = '\t'; /* delimiter, default is tab */
54 static struct cut_list *cut_lists = NULL; /* growable array holding a series of lists */
55 static unsigned int nlists = 0; /* number of elements in above list */
58 static int cmpfunc(const void *a, const void *b)
60 struct cut_list *la = (struct cut_list *)a;
61 struct cut_list *lb = (struct cut_list *)b;
63 if (la->startpos > lb->startpos)
65 if (la->startpos < lb->startpos)
72 * parse_lists() - parses a list and puts values into startpos and endpos.
73 * valid list formats: N, N-, N-M, -M
74 * more than one list can be separated by commas
76 static void parse_lists(char *lists)
83 /* take apart the lists, one by one (they are separated with commas */
84 while ((ltok = strsep(&lists, ",")) != NULL) {
86 /* it's actually legal to pass an empty list */
87 if (strlen(ltok) == 0)
90 /* get the start pos */
91 ntok = strsep(<ok, "-");
93 fprintf(stderr, "Help ntok is null for starting position! What do I do?\n");
94 } else if (strlen(ntok) == 0) {
97 s = strtoul(ntok, &junk, 10);
98 if(*junk != '\0' || s < 0)
99 bb_error_msg_and_die("invalid byte or field list");
101 /* account for the fact that arrays are zero based, while the user
102 * expects the first char on the line to be char # 1 */
107 /* get the end pos */
108 ntok = strsep(<ok, "-");
111 } else if (strlen(ntok) == 0) {
114 e = strtoul(ntok, &junk, 10);
115 if(*junk != '\0' || e < 0)
116 bb_error_msg_and_die("invalid byte or field list");
117 /* if the user specified and end position of 0, that means "til the
121 e--; /* again, arrays are zero based, lines are 1 based */
126 /* if there's something left to tokenize, the user past an invalid list */
128 bb_error_msg_and_die("invalid byte or field list");
130 /* add the new list */
131 cut_lists = xrealloc(cut_lists, sizeof(struct cut_list) * (++nlists));
132 cut_lists[nlists-1].startpos = s;
133 cut_lists[nlists-1].endpos = e;
136 /* make sure we got some cut positions out of all that */
138 bb_error_msg_and_die("missing list of positions");
140 /* now that the lists are parsed, we need to sort them to make life easier
141 * on us when it comes time to print the chars / fields / lines */
142 qsort(cut_lists, nlists, sizeof(struct cut_list), cmpfunc);
147 static void cut_line_by_chars(const char *line)
150 /* set up a list so we can keep track of what's been printed */
151 char *printed = xcalloc(strlen(line), sizeof(char));
153 /* print the chars specified in each cut list */
154 for (c = 0; c < nlists; c++) {
155 l = cut_lists[c].startpos;
156 while (l < strlen(line)) {
162 if (cut_lists[c].endpos == NON_RANGE || l > cut_lists[c].endpos)
166 putchar('\n'); /* cuz we were handed a chomped line */
171 static void cut_line_by_fields(char *line)
174 int ndelim = -1; /* zero-based / one-based problem */
175 int nfields_printed = 0;
177 char d[2] = { delim, 0 };
180 /* test the easy case first: does this line contain any delimiters? */
181 if (strchr(line, delim) == NULL) {
182 if (!supress_non_delimited_lines)
187 /* set up a list so we can keep track of what's been printed */
188 printed = xcalloc(strlen(line), sizeof(char));
190 /* process each list on this line, for as long as we've got a line to process */
191 for (c = 0; c < nlists && line; c++) {
192 f = cut_lists[c].startpos;
195 /* find the field we're looking for */
196 while (line && ndelim < f) {
197 field = strsep(&line, d);
201 /* we found it, and it hasn't been printed yet */
202 if (field && ndelim == f && !printed[ndelim]) {
203 /* if this isn't our first time through, we need to print the
204 * delimiter after the last field that was printed */
205 if (nfields_printed > 0)
207 fputs(field, stdout);
208 printed[ndelim] = 'X';
214 /* keep going as long as we have a line to work with, this is a
215 * list, and we're not at the end of that list */
216 } while (line && cut_lists[c].endpos != NON_RANGE && f <= cut_lists[c].endpos);
219 /* if we printed anything at all, we need to finish it with a newline cuz
220 * we were handed a chomped line */
227 static void cut_file_by_lines(const char *line, unsigned int linenum)
232 /* I can't initialize this above cuz the "initializer isn't
233 * constant" *sigh* */
235 l = cut_lists[c].startpos;
237 /* get out if we have no more lists to process or if the lines are lower
238 * than what we're interested in */
239 if (c >= nlists || linenum < l)
242 /* if the line we're looking for is lower than the one we were passed, it
243 * means we displayed it already, so move on */
244 while (l < linenum) {
246 /* move on to the next list if we're at the end of this one */
247 if (cut_lists[c].endpos == NON_RANGE || l > cut_lists[c].endpos) {
249 /* get out if there's no more lists to process */
252 l = cut_lists[c].startpos;
253 /* get out if the current line is lower than the one we just became
260 /* If we made it here, it means we've found the line we're looking for, so print it */
268 static void cut_file(FILE *file)
271 unsigned int linenum = 0; /* keep these zero-based to be consistent */
273 /* go through every line in the file */
274 while ((line = bb_get_chomped_line_from_file(file)) != NULL) {
276 /* cut based on chars/bytes XXX: only works when sizeof(char) == byte */
277 if ((part & (OPT_CHAR_FLGS | OPT_BYTE_FLGS)))
278 cut_line_by_chars(line);
280 /* cut based on fields */
283 cut_file_by_lines(line, linenum);
285 cut_line_by_fields(line);
294 int cut_main(int argc, char **argv)
299 bb_opt_complementally = "b--bcf:c--bcf:f--bcf";
300 opt = bb_getopt_ulflags(argc, argv, optstring, &sopt, &sopt, &sopt, &sdopt);
301 part = opt & (OPT_BYTE_FLGS|OPT_CHAR_FLGS|OPT_FIELDS_FLGS);
303 bb_error_msg_and_die("you must specify a list of bytes, characters, or fields");
304 if(opt & BB_GETOPT_ERROR)
305 bb_error_msg_and_die("only one type of list may be specified");
307 if((opt & (OPT_DELIM_FLGS))) {
308 if (strlen(sdopt) > 1) {
309 bb_error_msg_and_die("the delimiter must be a single character");
313 supress_non_delimited_lines = opt & OPT_SUPRESS_FLGS;
315 /* non-field (char or byte) cutting has some special handling */
316 if (part != OPT_FIELDS_FLGS) {
317 if (supress_non_delimited_lines) {
318 bb_error_msg_and_die("suppressing non-delimited lines makes sense"
319 " only when operating on fields");
322 bb_error_msg_and_die("a delimiter may be specified only when operating on fields");
326 /* argv[(optind)..(argc-1)] should be names of file to process. If no
327 * files were specified or '-' was specified, take input from stdin.
328 * Otherwise, we process all the files specified. */
329 if (argv[optind] == NULL || (strcmp(argv[optind], "-") == 0)) {
335 for (i = optind; i < argc; i++) {
336 file = bb_wfopen(argv[i], "r");