1 /* vi: set sw=4 ts=4: */
3 * cut.c - minimalist version of cut
5 * Copyright (C) 1999,2000,2001 by Lineo, inc.
6 * Written by Mark Whitley <markw@codepoet.org>
7 * debloated by Bernhard Reutner-Fischer
9 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
14 /* This is a NOEXEC applet. Be very careful! */
18 static const char optstring[] ALIGN1 = "b:c:f:d:sn";
19 #define CUT_OPT_BYTE_FLGS (1 << 0)
20 #define CUT_OPT_CHAR_FLGS (1 << 1)
21 #define CUT_OPT_FIELDS_FLGS (1 << 2)
22 #define CUT_OPT_DELIM_FLGS (1 << 3)
23 #define CUT_OPT_SUPPRESS_FLGS (1 << 4)
36 static int cmpfunc(const void *a, const void *b)
38 return (((struct cut_list *) a)->startpos -
39 ((struct cut_list *) b)->startpos);
42 static void cut_file(FILE *file, char delim, const struct cut_list *cut_lists, unsigned nlists)
45 unsigned linenum = 0; /* keep these zero-based to be consistent */
47 /* go through every line in the file */
48 while ((line = xmalloc_fgetline(file)) != NULL) {
50 /* set up a list so we can keep track of what's been printed */
51 int linelen = strlen(line);
52 char *printed = xzalloc(linelen + 1);
53 char *orig_line = line;
57 /* cut based on chars/bytes XXX: only works when sizeof(char) == byte */
58 if (option_mask32 & (CUT_OPT_CHAR_FLGS | CUT_OPT_BYTE_FLGS)) {
59 /* print the chars specified in each cut list */
60 for (; cl_pos < nlists; cl_pos++) {
61 spos = cut_lists[cl_pos].startpos;
62 while (spos < linelen) {
68 if (spos > cut_lists[cl_pos].endpos
69 /* NON_RANGE is -1, so if below is true,
70 * the above was true too (spos is >= 0) */
71 /* || cut_lists[cl_pos].endpos == NON_RANGE */
77 } else if (delim == '\n') { /* cut by lines */
78 spos = cut_lists[cl_pos].startpos;
80 /* get out if we have no more lists to process or if the lines
81 * are lower than what we're interested in */
82 if (((int)linenum < spos) || (cl_pos >= nlists))
85 /* if the line we're looking for is lower than the one we were
86 * passed, it means we displayed it already, so move on */
87 while (spos < (int)linenum) {
89 /* go to the next list if we're at the end of this one */
90 if (spos > cut_lists[cl_pos].endpos
91 || cut_lists[cl_pos].endpos == NON_RANGE
94 /* get out if there's no more lists to process */
97 spos = cut_lists[cl_pos].startpos;
98 /* get out if the current line is lower than the one
99 * we just became interested in */
100 if ((int)linenum < spos)
105 /* If we made it here, it means we've found the line we're
106 * looking for, so print it */
109 } else { /* cut by fields */
110 int ndelim = -1; /* zero-based / one-based problem */
111 int nfields_printed = 0;
115 delimiter[0] = delim;
118 /* does this line contain any delimiters? */
119 if (strchr(line, delim) == NULL) {
120 if (!(option_mask32 & CUT_OPT_SUPPRESS_FLGS))
125 /* process each list on this line, for as long as we've got
126 * a line to process */
127 for (; cl_pos < nlists && line; cl_pos++) {
128 spos = cut_lists[cl_pos].startpos;
130 /* find the field we're looking for */
131 while (line && ndelim < spos) {
132 field = strsep(&line, delimiter);
136 /* we found it, and it hasn't been printed yet */
137 if (field && ndelim == spos && !printed[ndelim]) {
138 /* if this isn't our first time through, we need to
139 * print the delimiter after the last field that was
141 if (nfields_printed > 0)
143 fputs(field, stdout);
144 printed[ndelim] = 'X';
145 nfields_printed++; /* shouldn't overflow.. */
150 /* keep going as long as we have a line to work with,
151 * this is a list, and we're not at the end of that
153 } while (spos <= cut_lists[cl_pos].endpos && line
154 && cut_lists[cl_pos].endpos != NON_RANGE);
157 /* if we printed anything at all, we need to finish it with a
158 * newline cuz we were handed a chomped line */
167 int cut_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
168 int cut_main(int argc UNUSED_PARAM, char **argv)
170 /* growable array holding a series of lists */
171 struct cut_list *cut_lists = NULL;
172 unsigned nlists = 0; /* number of elements in above list */
173 char delim = '\t'; /* delimiter, default is tab */
177 opt_complementary = "b--bcf:c--bcf:f--bcf";
178 opt = getopt32(argv, optstring, &sopt, &sopt, &sopt, <ok);
181 if (!(opt & (CUT_OPT_BYTE_FLGS | CUT_OPT_CHAR_FLGS | CUT_OPT_FIELDS_FLGS)))
182 bb_error_msg_and_die("expected a list of bytes, characters, or fields");
184 if (opt & CUT_OPT_DELIM_FLGS) {
185 if (ltok[0] && ltok[1]) { /* more than 1 char? */
186 bb_error_msg_and_die("the delimiter must be a single character");
191 /* non-field (char or byte) cutting has some special handling */
192 if (!(opt & CUT_OPT_FIELDS_FLGS)) {
193 static const char _op_on_field[] ALIGN1 = " only when operating on fields";
195 if (opt & CUT_OPT_SUPPRESS_FLGS) {
197 ("suppressing non-delimited lines makes sense%s",
202 ("a delimiter may be specified%s", _op_on_field);
207 * parse list and put values into startpos and endpos.
208 * valid list formats: N, N-, N-M, -M
209 * more than one list can be separated by commas
215 /* take apart the lists, one by one (they are separated with commas) */
216 while ((ltok = strsep(&sopt, ",")) != NULL) {
218 /* it's actually legal to pass an empty list */
222 /* get the start pos */
223 ntok = strsep(<ok, "-");
227 s = xatoi_positive(ntok);
228 /* account for the fact that arrays are zero based, while
229 * the user expects the first char on the line to be char #1 */
234 /* get the end pos */
237 } else if (!ltok[0]) {
240 e = xatoi_positive(ltok);
241 /* if the user specified and end position of 0,
242 * that means "til the end of the line" */
245 e--; /* again, arrays are zero based, lines are 1 based */
250 /* add the new list */
251 cut_lists = xrealloc_vector(cut_lists, 4, nlists);
252 /* NB: startpos is always >= 0,
253 * while endpos may be = NON_RANGE (-1) */
254 cut_lists[nlists].startpos = s;
255 cut_lists[nlists].endpos = e;
259 /* make sure we got some cut positions out of all that */
261 bb_error_msg_and_die("missing list of positions");
263 /* now that the lists are parsed, we need to sort them to make life
264 * easier on us when it comes time to print the chars / fields / lines
266 qsort(cut_lists, nlists, sizeof(cut_lists[0]), cmpfunc);
270 int retval = EXIT_SUCCESS;
273 *--argv = (char *)"-";
276 FILE *file = fopen_or_warn_stdin(*argv);
278 retval = EXIT_FAILURE;
281 cut_file(file, delim, cut_lists, nlists);
282 fclose_if_not_stdin(file);
285 if (ENABLE_FEATURE_CLEAN_UP)
287 fflush_stdout_and_exit(retval);