source: branches/3.2/mindi-busybox/coreutils/cut.c @ 3232

Last change on this file since 3232 was 3232, checked in by bruno, 5 years ago
  • Update mindi-busybox to 1.21.1
File size: 8.4 KB
Line 
1/* vi: set sw=4 ts=4: */
2/*
3 * cut.c - minimalist version of cut
4 *
5 * Copyright (C) 1999,2000,2001 by Lineo, inc.
6 * Written by Mark Whitley <markw@codepoet.org>
7 * debloated by Bernhard Reutner-Fischer
8 *
9 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
10 */
11
12//usage:#define cut_trivial_usage
13//usage:       "[OPTIONS] [FILE]..."
14//usage:#define cut_full_usage "\n\n"
15//usage:       "Print selected fields from each input FILE to stdout\n"
16//usage:     "\n    -b LIST Output only bytes from LIST"
17//usage:     "\n    -c LIST Output only characters from LIST"
18//usage:     "\n    -d CHAR Use CHAR instead of tab as the field delimiter"
19//usage:     "\n    -s  Output only the lines containing delimiter"
20//usage:     "\n    -f N    Print only these fields"
21//usage:     "\n    -n  Ignored"
22//usage:
23//usage:#define cut_example_usage
24//usage:       "$ echo \"Hello world\" | cut -f 1 -d ' '\n"
25//usage:       "Hello\n"
26//usage:       "$ echo \"Hello world\" | cut -f 2 -d ' '\n"
27//usage:       "world\n"
28
29#include "libbb.h"
30
31/* This is a NOEXEC applet. Be very careful! */
32
33
34/* option vars */
35static const char optstring[] ALIGN1 = "b:c:f:d:sn";
36#define CUT_OPT_BYTE_FLGS     (1 << 0)
37#define CUT_OPT_CHAR_FLGS     (1 << 1)
38#define CUT_OPT_FIELDS_FLGS   (1 << 2)
39#define CUT_OPT_DELIM_FLGS    (1 << 3)
40#define CUT_OPT_SUPPRESS_FLGS (1 << 4)
41
42struct cut_list {
43    int startpos;
44    int endpos;
45};
46
47enum {
48    BOL = 0,
49    EOL = INT_MAX,
50    NON_RANGE = -1
51};
52
53static int cmpfunc(const void *a, const void *b)
54{
55    return (((struct cut_list *) a)->startpos -
56            ((struct cut_list *) b)->startpos);
57}
58
59static void cut_file(FILE *file, char delim, const struct cut_list *cut_lists, unsigned nlists)
60{
61    char *line;
62    unsigned linenum = 0;   /* keep these zero-based to be consistent */
63
64    /* go through every line in the file */
65    while ((line = xmalloc_fgetline(file)) != NULL) {
66
67        /* set up a list so we can keep track of what's been printed */
68        int linelen = strlen(line);
69        char *printed = xzalloc(linelen + 1);
70        char *orig_line = line;
71        unsigned cl_pos = 0;
72        int spos;
73
74        /* cut based on chars/bytes XXX: only works when sizeof(char) == byte */
75        if (option_mask32 & (CUT_OPT_CHAR_FLGS | CUT_OPT_BYTE_FLGS)) {
76            /* print the chars specified in each cut list */
77            for (; cl_pos < nlists; cl_pos++) {
78                spos = cut_lists[cl_pos].startpos;
79                while (spos < linelen) {
80                    if (!printed[spos]) {
81                        printed[spos] = 'X';
82                        putchar(line[spos]);
83                    }
84                    spos++;
85                    if (spos > cut_lists[cl_pos].endpos
86                    /* NON_RANGE is -1, so if below is true,
87                     * the above was true too (spos is >= 0) */
88                    /* || cut_lists[cl_pos].endpos == NON_RANGE */
89                    ) {
90                        break;
91                    }
92                }
93            }
94        } else if (delim == '\n') { /* cut by lines */
95            spos = cut_lists[cl_pos].startpos;
96
97            /* get out if we have no more lists to process or if the lines
98             * are lower than what we're interested in */
99            if (((int)linenum < spos) || (cl_pos >= nlists))
100                goto next_line;
101
102            /* if the line we're looking for is lower than the one we were
103             * passed, it means we displayed it already, so move on */
104            while (spos < (int)linenum) {
105                spos++;
106                /* go to the next list if we're at the end of this one */
107                if (spos > cut_lists[cl_pos].endpos
108                 || cut_lists[cl_pos].endpos == NON_RANGE
109                ) {
110                    cl_pos++;
111                    /* get out if there's no more lists to process */
112                    if (cl_pos >= nlists)
113                        goto next_line;
114                    spos = cut_lists[cl_pos].startpos;
115                    /* get out if the current line is lower than the one
116                     * we just became interested in */
117                    if ((int)linenum < spos)
118                        goto next_line;
119                }
120            }
121
122            /* If we made it here, it means we've found the line we're
123             * looking for, so print it */
124            puts(line);
125            goto next_line;
126        } else {        /* cut by fields */
127            int ndelim = -1;    /* zero-based / one-based problem */
128            int nfields_printed = 0;
129            char *field = NULL;
130            char delimiter[2];
131
132            delimiter[0] = delim;
133            delimiter[1] = 0;
134
135            /* does this line contain any delimiters? */
136            if (strchr(line, delim) == NULL) {
137                if (!(option_mask32 & CUT_OPT_SUPPRESS_FLGS))
138                    puts(line);
139                goto next_line;
140            }
141
142            /* process each list on this line, for as long as we've got
143             * a line to process */
144            for (; cl_pos < nlists && line; cl_pos++) {
145                spos = cut_lists[cl_pos].startpos;
146                do {
147                    /* find the field we're looking for */
148                    while (line && ndelim < spos) {
149                        field = strsep(&line, delimiter);
150                        ndelim++;
151                    }
152
153                    /* we found it, and it hasn't been printed yet */
154                    if (field && ndelim == spos && !printed[ndelim]) {
155                        /* if this isn't our first time through, we need to
156                         * print the delimiter after the last field that was
157                         * printed */
158                        if (nfields_printed > 0)
159                            putchar(delim);
160                        fputs(field, stdout);
161                        printed[ndelim] = 'X';
162                        nfields_printed++;  /* shouldn't overflow.. */
163                    }
164
165                    spos++;
166
167                    /* keep going as long as we have a line to work with,
168                     * this is a list, and we're not at the end of that
169                     * list */
170                } while (spos <= cut_lists[cl_pos].endpos && line
171                        && cut_lists[cl_pos].endpos != NON_RANGE);
172            }
173        }
174        /* if we printed anything at all, we need to finish it with a
175         * newline cuz we were handed a chomped line */
176        putchar('\n');
177 next_line:
178        linenum++;
179        free(printed);
180        free(orig_line);
181    }
182}
183
184int cut_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
185int cut_main(int argc UNUSED_PARAM, char **argv)
186{
187    /* growable array holding a series of lists */
188    struct cut_list *cut_lists = NULL;
189    unsigned nlists = 0;    /* number of elements in above list */
190    char delim = '\t';  /* delimiter, default is tab */
191    char *sopt, *ltok;
192    unsigned opt;
193
194    opt_complementary = "b--bcf:c--bcf:f--bcf";
195    opt = getopt32(argv, optstring, &sopt, &sopt, &sopt, &ltok);
196//  argc -= optind;
197    argv += optind;
198    if (!(opt & (CUT_OPT_BYTE_FLGS | CUT_OPT_CHAR_FLGS | CUT_OPT_FIELDS_FLGS)))
199        bb_error_msg_and_die("expected a list of bytes, characters, or fields");
200
201    if (opt & CUT_OPT_DELIM_FLGS) {
202        if (ltok[0] && ltok[1]) { /* more than 1 char? */
203            bb_error_msg_and_die("the delimiter must be a single character");
204        }
205        delim = ltok[0];
206    }
207
208    /*  non-field (char or byte) cutting has some special handling */
209    if (!(opt & CUT_OPT_FIELDS_FLGS)) {
210        static const char _op_on_field[] ALIGN1 = " only when operating on fields";
211
212        if (opt & CUT_OPT_SUPPRESS_FLGS) {
213            bb_error_msg_and_die
214                ("suppressing non-delimited lines makes sense%s",
215                _op_on_field);
216        }
217        if (delim != '\t') {
218            bb_error_msg_and_die
219                ("a delimiter may be specified%s", _op_on_field);
220        }
221    }
222
223    /*
224     * parse list and put values into startpos and endpos.
225     * valid list formats: N, N-, N-M, -M
226     * more than one list can be separated by commas
227     */
228    {
229        char *ntok;
230        int s = 0, e = 0;
231
232        /* take apart the lists, one by one (they are separated with commas) */
233        while ((ltok = strsep(&sopt, ",")) != NULL) {
234
235            /* it's actually legal to pass an empty list */
236            if (!ltok[0])
237                continue;
238
239            /* get the start pos */
240            ntok = strsep(&ltok, "-");
241            if (!ntok[0]) {
242                s = BOL;
243            } else {
244                s = xatoi_positive(ntok);
245                /* account for the fact that arrays are zero based, while
246                 * the user expects the first char on the line to be char #1 */
247                if (s != 0)
248                    s--;
249            }
250
251            /* get the end pos */
252            if (ltok == NULL) {
253                e = NON_RANGE;
254            } else if (!ltok[0]) {
255                e = EOL;
256            } else {
257                e = xatoi_positive(ltok);
258                /* if the user specified and end position of 0,
259                 * that means "til the end of the line" */
260                if (e == 0)
261                    e = EOL;
262                e--;    /* again, arrays are zero based, lines are 1 based */
263                if (e == s)
264                    e = NON_RANGE;
265            }
266
267            /* add the new list */
268            cut_lists = xrealloc_vector(cut_lists, 4, nlists);
269            /* NB: startpos is always >= 0,
270             * while endpos may be = NON_RANGE (-1) */
271            cut_lists[nlists].startpos = s;
272            cut_lists[nlists].endpos = e;
273            nlists++;
274        }
275
276        /* make sure we got some cut positions out of all that */
277        if (nlists == 0)
278            bb_error_msg_and_die("missing list of positions");
279
280        /* now that the lists are parsed, we need to sort them to make life
281         * easier on us when it comes time to print the chars / fields / lines
282         */
283        qsort(cut_lists, nlists, sizeof(cut_lists[0]), cmpfunc);
284    }
285
286    {
287        int retval = EXIT_SUCCESS;
288
289        if (!*argv)
290            *--argv = (char *)"-";
291
292        do {
293            FILE *file = fopen_or_warn_stdin(*argv);
294            if (!file) {
295                retval = EXIT_FAILURE;
296                continue;
297            }
298            cut_file(file, delim, cut_lists, nlists);
299            fclose_if_not_stdin(file);
300        } while (*++argv);
301
302        if (ENABLE_FEATURE_CLEAN_UP)
303            free(cut_lists);
304        fflush_stdout_and_exit(retval);
305    }
306}
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