Contents of /tags/mkinitrd-6_1_10/busybox/coreutils/cut.c
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Wed Oct 28 09:51:31 2009 UTC (14 years, 11 months ago) by niro
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Wed Oct 28 09:51:31 2009 UTC (14 years, 11 months ago) by niro
File MIME type: text/plain
File size: 7876 byte(s)
tagged 'mkinitrd-6_1_10'
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 tarball for details. |
10 | */ |
11 | |
12 | #include "libbb.h" |
13 | |
14 | /* This is a NOEXEC applet. Be very careful! */ |
15 | |
16 | |
17 | /* option vars */ |
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) |
24 | |
25 | struct cut_list { |
26 | int startpos; |
27 | int endpos; |
28 | }; |
29 | |
30 | enum { |
31 | BOL = 0, |
32 | EOL = INT_MAX, |
33 | NON_RANGE = -1 |
34 | }; |
35 | |
36 | static int cmpfunc(const void *a, const void *b) |
37 | { |
38 | return (((struct cut_list *) a)->startpos - |
39 | ((struct cut_list *) b)->startpos); |
40 | |
41 | } |
42 | |
43 | static void cut_file(FILE *file, char delim, const struct cut_list *cut_lists, unsigned nlists) |
44 | { |
45 | char *line; |
46 | unsigned linenum = 0; /* keep these zero-based to be consistent */ |
47 | |
48 | /* go through every line in the file */ |
49 | while ((line = xmalloc_fgetline(file)) != NULL) { |
50 | |
51 | /* set up a list so we can keep track of what's been printed */ |
52 | int linelen = strlen(line); |
53 | char *printed = xzalloc(linelen + 1); |
54 | char *orig_line = line; |
55 | unsigned cl_pos = 0; |
56 | int spos; |
57 | |
58 | /* cut based on chars/bytes XXX: only works when sizeof(char) == byte */ |
59 | if (option_mask32 & (CUT_OPT_CHAR_FLGS | CUT_OPT_BYTE_FLGS)) { |
60 | /* print the chars specified in each cut list */ |
61 | for (; cl_pos < nlists; cl_pos++) { |
62 | spos = cut_lists[cl_pos].startpos; |
63 | while (spos < linelen) { |
64 | if (!printed[spos]) { |
65 | printed[spos] = 'X'; |
66 | putchar(line[spos]); |
67 | } |
68 | spos++; |
69 | if (spos > cut_lists[cl_pos].endpos |
70 | /* NON_RANGE is -1, so if below is true, |
71 | * the above was true too (spos is >= 0) */ |
72 | /* || cut_lists[cl_pos].endpos == NON_RANGE */ |
73 | ) { |
74 | break; |
75 | } |
76 | } |
77 | } |
78 | } else if (delim == '\n') { /* cut by lines */ |
79 | spos = cut_lists[cl_pos].startpos; |
80 | |
81 | /* get out if we have no more lists to process or if the lines |
82 | * are lower than what we're interested in */ |
83 | if (((int)linenum < spos) || (cl_pos >= nlists)) |
84 | goto next_line; |
85 | |
86 | /* if the line we're looking for is lower than the one we were |
87 | * passed, it means we displayed it already, so move on */ |
88 | while (spos < (int)linenum) { |
89 | spos++; |
90 | /* go to the next list if we're at the end of this one */ |
91 | if (spos > cut_lists[cl_pos].endpos |
92 | || cut_lists[cl_pos].endpos == NON_RANGE |
93 | ) { |
94 | cl_pos++; |
95 | /* get out if there's no more lists to process */ |
96 | if (cl_pos >= nlists) |
97 | goto next_line; |
98 | spos = cut_lists[cl_pos].startpos; |
99 | /* get out if the current line is lower than the one |
100 | * we just became interested in */ |
101 | if ((int)linenum < spos) |
102 | goto next_line; |
103 | } |
104 | } |
105 | |
106 | /* If we made it here, it means we've found the line we're |
107 | * looking for, so print it */ |
108 | puts(line); |
109 | goto next_line; |
110 | } else { /* cut by fields */ |
111 | int ndelim = -1; /* zero-based / one-based problem */ |
112 | int nfields_printed = 0; |
113 | char *field = NULL; |
114 | const char delimiter[2] = { delim, 0 }; |
115 | |
116 | /* does this line contain any delimiters? */ |
117 | if (strchr(line, delim) == NULL) { |
118 | if (!(option_mask32 & CUT_OPT_SUPPRESS_FLGS)) |
119 | puts(line); |
120 | goto next_line; |
121 | } |
122 | |
123 | /* process each list on this line, for as long as we've got |
124 | * a line to process */ |
125 | for (; cl_pos < nlists && line; cl_pos++) { |
126 | spos = cut_lists[cl_pos].startpos; |
127 | do { |
128 | /* find the field we're looking for */ |
129 | while (line && ndelim < spos) { |
130 | field = strsep(&line, delimiter); |
131 | ndelim++; |
132 | } |
133 | |
134 | /* we found it, and it hasn't been printed yet */ |
135 | if (field && ndelim == spos && !printed[ndelim]) { |
136 | /* if this isn't our first time through, we need to |
137 | * print the delimiter after the last field that was |
138 | * printed */ |
139 | if (nfields_printed > 0) |
140 | putchar(delim); |
141 | fputs(field, stdout); |
142 | printed[ndelim] = 'X'; |
143 | nfields_printed++; /* shouldn't overflow.. */ |
144 | } |
145 | |
146 | spos++; |
147 | |
148 | /* keep going as long as we have a line to work with, |
149 | * this is a list, and we're not at the end of that |
150 | * list */ |
151 | } while (spos <= cut_lists[cl_pos].endpos && line |
152 | && cut_lists[cl_pos].endpos != NON_RANGE); |
153 | } |
154 | } |
155 | /* if we printed anything at all, we need to finish it with a |
156 | * newline cuz we were handed a chomped line */ |
157 | putchar('\n'); |
158 | next_line: |
159 | linenum++; |
160 | free(printed); |
161 | free(orig_line); |
162 | } |
163 | } |
164 | |
165 | int cut_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; |
166 | int cut_main(int argc UNUSED_PARAM, char **argv) |
167 | { |
168 | /* growable array holding a series of lists */ |
169 | struct cut_list *cut_lists = NULL; |
170 | unsigned nlists = 0; /* number of elements in above list */ |
171 | char delim = '\t'; /* delimiter, default is tab */ |
172 | char *sopt, *ltok; |
173 | unsigned opt; |
174 | |
175 | opt_complementary = "b--bcf:c--bcf:f--bcf"; |
176 | opt = getopt32(argv, optstring, &sopt, &sopt, &sopt, <ok); |
177 | // argc -= optind; |
178 | argv += optind; |
179 | if (!(opt & (CUT_OPT_BYTE_FLGS | CUT_OPT_CHAR_FLGS | CUT_OPT_FIELDS_FLGS))) |
180 | bb_error_msg_and_die("expected a list of bytes, characters, or fields"); |
181 | |
182 | if (opt & CUT_OPT_DELIM_FLGS) { |
183 | if (ltok[0] && ltok[1]) { /* more than 1 char? */ |
184 | bb_error_msg_and_die("the delimiter must be a single character"); |
185 | } |
186 | delim = ltok[0]; |
187 | } |
188 | |
189 | /* non-field (char or byte) cutting has some special handling */ |
190 | if (!(opt & CUT_OPT_FIELDS_FLGS)) { |
191 | static const char _op_on_field[] ALIGN1 = " only when operating on fields"; |
192 | |
193 | if (opt & CUT_OPT_SUPPRESS_FLGS) { |
194 | bb_error_msg_and_die |
195 | ("suppressing non-delimited lines makes sense%s", |
196 | _op_on_field); |
197 | } |
198 | if (delim != '\t') { |
199 | bb_error_msg_and_die |
200 | ("a delimiter may be specified%s", _op_on_field); |
201 | } |
202 | } |
203 | |
204 | /* |
205 | * parse list and put values into startpos and endpos. |
206 | * valid list formats: N, N-, N-M, -M |
207 | * more than one list can be separated by commas |
208 | */ |
209 | { |
210 | char *ntok; |
211 | int s = 0, e = 0; |
212 | |
213 | /* take apart the lists, one by one (they are separated with commas) */ |
214 | while ((ltok = strsep(&sopt, ",")) != NULL) { |
215 | |
216 | /* it's actually legal to pass an empty list */ |
217 | if (!ltok[0]) |
218 | continue; |
219 | |
220 | /* get the start pos */ |
221 | ntok = strsep(<ok, "-"); |
222 | if (!ntok[0]) { |
223 | s = BOL; |
224 | } else { |
225 | s = xatoi_u(ntok); |
226 | /* account for the fact that arrays are zero based, while |
227 | * the user expects the first char on the line to be char #1 */ |
228 | if (s != 0) |
229 | s--; |
230 | } |
231 | |
232 | /* get the end pos */ |
233 | if (ltok == NULL) { |
234 | e = NON_RANGE; |
235 | } else if (!ltok[0]) { |
236 | e = EOL; |
237 | } else { |
238 | e = xatoi_u(ltok); |
239 | /* if the user specified and end position of 0, |
240 | * that means "til the end of the line" */ |
241 | if (e == 0) |
242 | e = EOL; |
243 | e--; /* again, arrays are zero based, lines are 1 based */ |
244 | if (e == s) |
245 | e = NON_RANGE; |
246 | } |
247 | |
248 | /* add the new list */ |
249 | cut_lists = xrealloc_vector(cut_lists, 4, nlists); |
250 | /* NB: startpos is always >= 0, |
251 | * while endpos may be = NON_RANGE (-1) */ |
252 | cut_lists[nlists].startpos = s; |
253 | cut_lists[nlists].endpos = e; |
254 | nlists++; |
255 | } |
256 | |
257 | /* make sure we got some cut positions out of all that */ |
258 | if (nlists == 0) |
259 | bb_error_msg_and_die("missing list of positions"); |
260 | |
261 | /* now that the lists are parsed, we need to sort them to make life |
262 | * easier on us when it comes time to print the chars / fields / lines |
263 | */ |
264 | qsort(cut_lists, nlists, sizeof(struct cut_list), cmpfunc); |
265 | } |
266 | |
267 | { |
268 | int retval = EXIT_SUCCESS; |
269 | |
270 | if (!*argv) |
271 | *--argv = (char *)"-"; |
272 | |
273 | do { |
274 | FILE *file = fopen_or_warn_stdin(*argv); |
275 | if (!file) { |
276 | retval = EXIT_FAILURE; |
277 | continue; |
278 | } |
279 | cut_file(file, delim, cut_lists, nlists); |
280 | fclose_if_not_stdin(file); |
281 | } while (*++argv); |
282 | |
283 | if (ENABLE_FEATURE_CLEAN_UP) |
284 | free(cut_lists); |
285 | fflush_stdout_and_exit(retval); |
286 | } |
287 | } |