blob: 62477af163f84d440eaac704798af83626cd911d [file] [log] [blame]
Rob Landley1bbc0cd2010-08-13 15:50:26 +02001/* vi: set sw=4 ts=4: */
2/*
3 * busybox patch applet to handle the unified diff format.
4 * Copyright (C) 2003 Glenn McGrath
5 *
6 * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
7 *
8 * This applet is written to work with patches generated by GNU diff,
9 * where there is equivalent functionality busybox patch shall behave
10 * as per GNU patch.
11 *
12 * There is a SUSv3 specification for patch, however it looks to be
13 * incomplete, it doesnt even mention unified diff format.
14 * http://www.opengroup.org/onlinepubs/007904975/utilities/patch.html
15 *
16 * Issues
17 * - Non-interactive
18 * - Patches must apply cleanly or patch (not just one hunk) will fail.
19 * - Reject file isnt saved
20 */
21
22#include "libbb.h"
23
24static unsigned copy_lines(FILE *src_stream, FILE *dst_stream, unsigned lines_count)
25{
26 while (src_stream && lines_count) {
27 char *line;
28 line = xmalloc_fgets(src_stream);
29 if (line == NULL) {
30 break;
31 }
32 if (fputs(line, dst_stream) == EOF) {
33 bb_perror_msg_and_die("error writing to new file");
34 }
35 free(line);
36 lines_count--;
37 }
38 return lines_count;
39}
40
41/* If patch_level is -1 it will remove all directory names
42 * char *line must be greater than 4 chars
43 * returns NULL if the file doesnt exist or error
44 * returns malloc'ed filename
45 * NB: frees 1st argument!
46 */
47static char *extract_filename(char *line, int patch_level, const char *pat)
48{
49 char *temp = NULL, *filename_start_ptr = line + 4;
50
51 if (strncmp(line, pat, 4) == 0) {
52 /* Terminate string at end of source filename */
53 line[strcspn(line, "\t\n\r")] = '\0';
54
55 /* Skip over (patch_level) number of leading directories */
56 while (patch_level--) {
57 temp = strchr(filename_start_ptr, '/');
58 if (!temp)
59 break;
60 filename_start_ptr = temp + 1;
61 }
62 temp = xstrdup(filename_start_ptr);
63 }
64 free(line);
65 return temp;
66}
67
68int patch_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
69int patch_main(int argc UNUSED_PARAM, char **argv)
70{
71 struct stat saved_stat;
72 char *patch_line;
73 FILE *patch_file;
74 int patch_level;
75 int ret = 0;
76 char plus = '+';
77 unsigned opt;
78 enum {
79 OPT_R = (1 << 2),
80 OPT_N = (1 << 3),
81 /*OPT_f = (1 << 4), ignored */
82 /*OPT_E = (1 << 5), ignored, this is the default */
83 /*OPT_g = (1 << 6), ignored */
84 OPT_dry_run = (1 << 7) * ENABLE_LONG_OPTS,
85 };
86
87 xfunc_error_retval = 2;
88 {
89 const char *p = "-1";
90 const char *i = "-"; /* compat */
91#if ENABLE_LONG_OPTS
92 static const char patch_longopts[] ALIGN1 =
93 "strip\0" Required_argument "p"
94 "input\0" Required_argument "i"
95 "reverse\0" No_argument "R"
96 "forward\0" No_argument "N"
97 /* "Assume user knows what [s]he is doing, do not ask any questions": */
98 "force\0" No_argument "f" /*ignored*/
99# if ENABLE_DESKTOP
100 "remove-empty-files\0" No_argument "E" /*ignored*/
101 /* "Controls actions when a file is under RCS or SCCS control,
102 * and does not exist or is read-only and matches the default version,
103 * or when a file is under ClearCase control and does not exist..."
104 * IOW: rather obscure option.
105 * But Gentoo's portage does use -g0 */
106 "get\0" Required_argument "g" /*ignored*/
107# endif
108 "dry-run\0" No_argument "\xfd"
109# if ENABLE_DESKTOP
110 "backup-if-mismatch\0" No_argument "\xfe" /*ignored*/
111 "no-backup-if-mismatch\0" No_argument "\xff" /*ignored*/
112# endif
113 ;
114 applet_long_options = patch_longopts;
115#endif
116 /* -f,-E,-g are ignored */
117 opt = getopt32(argv, "p:i:RN""fEg:", &p, &i, NULL);
118 if (opt & OPT_R)
119 plus = '-';
120 patch_level = xatoi(p); /* can be negative! */
121 patch_file = xfopen_stdin(i);
122 }
123
124 patch_line = xmalloc_fgetline(patch_file);
125 while (patch_line) {
126 FILE *src_stream;
127 FILE *dst_stream;
128 //char *old_filename;
129 char *new_filename;
130 char *backup_filename = NULL;
131 unsigned src_cur_line = 1;
132 unsigned dst_cur_line = 0;
133 unsigned dst_beg_line;
134 unsigned bad_hunk_count = 0;
135 unsigned hunk_count = 0;
136 smallint copy_trailing_lines_flag = 0;
137
138 /* Skip everything upto the "---" marker
139 * No need to parse the lines "Only in <dir>", and "diff <args>"
140 */
141 do {
142 /* Extract the filename used before the patch was generated */
143 new_filename = extract_filename(patch_line, patch_level, "--- ");
144 // was old_filename above
145 patch_line = xmalloc_fgetline(patch_file);
146 if (!patch_line) goto quit;
147 } while (!new_filename);
148 free(new_filename); // "source" filename is irrelevant
149
150 new_filename = extract_filename(patch_line, patch_level, "+++ ");
151 if (!new_filename) {
152 bb_error_msg_and_die("invalid patch");
153 }
154
155 /* Get access rights from the file to be patched */
156 if (stat(new_filename, &saved_stat) != 0) {
157 char *slash = strrchr(new_filename, '/');
158 if (slash) {
159 /* Create leading directories */
160 *slash = '\0';
161 bb_make_directory(new_filename, -1, FILEUTILS_RECUR);
162 *slash = '/';
163 }
164 src_stream = NULL;
165 saved_stat.st_mode = 0644;
166 } else if (!(opt & OPT_dry_run)) {
167 backup_filename = xasprintf("%s.orig", new_filename);
168 xrename(new_filename, backup_filename);
169 src_stream = xfopen_for_read(backup_filename);
170 } else
171 src_stream = xfopen_for_read(new_filename);
172
173 if (opt & OPT_dry_run) {
174 dst_stream = xfopen_for_write("/dev/null");
175 } else {
176 dst_stream = xfopen_for_write(new_filename);
177 fchmod(fileno(dst_stream), saved_stat.st_mode);
178 }
179
180 printf("patching file %s\n", new_filename);
181
182 /* Handle all hunks for this file */
183 patch_line = xmalloc_fgets(patch_file);
184 while (patch_line) {
185 unsigned count;
186 unsigned src_beg_line;
187 unsigned hunk_offset_start;
188 unsigned src_last_line = 1;
189 unsigned dst_last_line = 1;
190
191 if ((sscanf(patch_line, "@@ -%d,%d +%d,%d", &src_beg_line, &src_last_line, &dst_beg_line, &dst_last_line) < 3)
192 && (sscanf(patch_line, "@@ -%d +%d,%d", &src_beg_line, &dst_beg_line, &dst_last_line) < 2)
193 ) {
194 /* No more hunks for this file */
195 break;
196 }
197 if (plus != '+') {
198 /* reverse patch */
199 unsigned tmp = src_last_line;
200 src_last_line = dst_last_line;
201 dst_last_line = tmp;
202 tmp = src_beg_line;
203 src_beg_line = dst_beg_line;
204 dst_beg_line = tmp;
205 }
206 hunk_count++;
207
208 if (src_beg_line && dst_beg_line) {
209 /* Copy unmodified lines upto start of hunk */
210 /* src_beg_line will be 0 if it's a new file */
211 count = src_beg_line - src_cur_line;
212 if (copy_lines(src_stream, dst_stream, count)) {
213 bb_error_msg_and_die("bad src file");
214 }
215 src_cur_line += count;
216 dst_cur_line += count;
217 copy_trailing_lines_flag = 1;
218 }
219 src_last_line += hunk_offset_start = src_cur_line;
220 dst_last_line += dst_cur_line;
221
222 while (1) {
223 free(patch_line);
224 patch_line = xmalloc_fgets(patch_file);
225 if (patch_line == NULL)
226 break; /* EOF */
227 if (!*patch_line) {
228 /* whitespace-damaged patch with "" lines */
229 free(patch_line);
230 patch_line = xstrdup(" ");
231 }
232 if ((*patch_line != '-') && (*patch_line != '+')
233 && (*patch_line != ' ')
234 ) {
235 break; /* End of hunk */
236 }
237 if (*patch_line != plus) { /* '-' or ' ' */
238 char *src_line = NULL;
239 if (src_cur_line == src_last_line)
240 break;
241 if (src_stream) {
242 src_line = xmalloc_fgets(src_stream);
243 if (src_line) {
244 int diff = strcmp(src_line, patch_line + 1);
245 src_cur_line++;
246 free(src_line);
247 if (diff)
248 src_line = NULL;
249 }
250 }
251 /* Do not patch an already patched hunk with -N */
252 if (src_line == 0 && (opt & OPT_N)) {
253 continue;
254 }
255 if (!src_line) {
256 bb_error_msg("hunk #%u FAILED at %u", hunk_count, hunk_offset_start);
257 bad_hunk_count++;
258 break;
259 }
260 if (*patch_line != ' ') { /* '-' */
261 continue;
262 }
263 }
264 if (dst_cur_line == dst_last_line)
265 break;
266 fputs(patch_line + 1, dst_stream);
267 dst_cur_line++;
268 } /* end of while loop handling one hunk */
269 } /* end of while loop handling one file */
270
271 /* Cleanup last patched file */
272 if (copy_trailing_lines_flag) {
273 copy_lines(src_stream, dst_stream, (unsigned)(-1));
274 }
275 if (src_stream) {
276 fclose(src_stream);
277 }
278 fclose(dst_stream);
279 if (bad_hunk_count) {
280 ret = 1;
281 bb_error_msg("%u out of %u hunk FAILED", bad_hunk_count, hunk_count);
282 } else {
283 /* It worked, we can remove the backup */
284 if (backup_filename) {
285 unlink(backup_filename);
286 }
287 if (!(opt & OPT_dry_run)
288 && ((dst_cur_line == 0) || (dst_beg_line == 0))
289 ) {
290 /* The new patched file is empty, remove it */
291 xunlink(new_filename);
292 // /* old_filename and new_filename may be the same file */
293 // unlink(old_filename);
294 }
295 }
296 free(backup_filename);
297 //free(old_filename);
298 free(new_filename);
299 } /* end of "while there are patch lines" */
300 quit:
301 /* 0 = SUCCESS
302 * 1 = Some hunks failed
303 * 2 = More serious problems (exited earlier)
304 */
305 return ret;
306}