blob: 1587919bca22ed5d81921042ac1cfcfe250c85a9 [file] [log] [blame]
Glenn L McGrath655d8142003-06-22 15:32:41 +00001/* vi: set sw=4 ts=4: */
2/*
3 * busybox patch applet to handle the unified diff format.
4 * Copyright (C) 2003 Glenn McGrath <bug1@optushome.com.au>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
19 *
20 *
21 *
22 * This applet is written to work with patches generated by GNU diff,
23 * where there is equivalent functionality busybox patch shall behave
24 * as per GNU patch.
25 *
26 * There is a SUSv3 specification for patch, however it looks to be
27 * incomplete, it doesnt even mention unified diff format.
28 * http://www.opengroup.org/onlinepubs/007904975/utilities/patch.html
29 *
30 * Issues
31 * - Non-interactive
32 * - Patches must apply cleanly or the hunk will fail.
33 * - Reject file isnt saved
34 * -
35 */
36
37#include <getopt.h>
38#include <string.h>
39#include <stdlib.h>
40#include <unistd.h>
41#include "busybox.h"
42#include "libbb.h"
43
44static int copy_lines(FILE *src_stream, FILE *dest_stream, const unsigned int lines_count)
45{
46 int i = 0;
47
48 while (src_stream && (i < lines_count)) {
49 char *line;
50 line = bb_get_line_from_file(src_stream);
51 if (line == NULL) {
52 break;
53 }
54 if (fputs(line, dest_stream) == EOF) {
55 bb_perror_msg_and_die("Error writing to new file");
56 }
57 free(line);
58
59 i++;
60 }
61 return(i);
62}
63
64/* If patch_level is -1 it will remove all directory names
65 * char *line must be greater than 4 chars
66 * returns NULL if the file doesnt exist or error
67 * returns malloc'ed filename
68 */
69
70static unsigned char *extract_filename(char *line, unsigned short patch_level)
71{
72 char *filename_start_ptr = line + 4;
73 int i;
74
75 /* Terminate string at end of source filename */
76 {
77 char *line_ptr;
78 line_ptr = strchr(filename_start_ptr, '\t');
79 if (!line_ptr) {
80 bb_perror_msg("Malformed line %s", line);
81 return(NULL);
82 }
83 *line_ptr = '\0';
84 }
85
86 /* Skip over (patch_level) number of leading directories */
87 for (i = 0; i < patch_level; i++) {
88 char *dirname_ptr;
89
90 dirname_ptr = strchr(filename_start_ptr, '/');
91 if (!dirname_ptr) {
92 break;
93 }
94 filename_start_ptr = dirname_ptr + 1;
95 }
96
97 return(bb_xstrdup(filename_start_ptr));
98}
99
100static int file_doesnt_exist(const char *filename)
101{
102 struct stat statbuf;
103 return(stat(filename, &statbuf));
104}
105
106extern int patch_main(int argc, char **argv)
107{
108 unsigned int patch_level = -1;
109 char *patch_line;
110 int ret = 0;
111
112 /* Handle 'p' option */
113 if (argv[1] && (argv[1][0] == '-') && (argv[1][1] == 'p')) {
114 patch_level = atoi(&argv[1][2]);
115 }
116
117 patch_line = bb_get_line_from_file(stdin);
118 while (patch_line) {
119 FILE *src_stream;
120 FILE *dst_stream;
121 char *original_filename;
122 char *new_filename;
123 char *backup_filename;
124 unsigned int src_cur_line = 1;
125 unsigned int dest_cur_line = 0;
126 unsigned int dest_beg_line;
127 unsigned int bad_hunk_count = 0;
128 unsigned int hunk_count = 0;
129 char copy_trailing_lines_flag = 0;
130
131 /* Skip everything upto the "---" marker
132 * No need to parse the lines "Only in <dir>", and "diff <args>"
133 */
134 while (patch_line && strncmp(patch_line, "--- ", 4) != 0) {
135 free(patch_line);
136 patch_line = bb_get_line_from_file(stdin);
137 }
138
139 /* Extract the filename used before the patch was generated */
140 original_filename = extract_filename(patch_line, patch_level);
141 free(patch_line);
142
143 patch_line = bb_get_line_from_file(stdin);
144 if (strncmp(patch_line, "+++ ", 4) != 0) {
145 ret = 2;
146 bb_error_msg("Invalid patch");
147 continue;
148 }
149 new_filename = extract_filename(patch_line, patch_level);
150 free(patch_line);
151
152 if (file_doesnt_exist(new_filename)) {
153 char *line_ptr;
154 /* Create leading directories */
155 line_ptr = strrchr(new_filename, '/');
156 if (line_ptr) {
157 *line_ptr = '\0';
158 bb_make_directory(new_filename, -1, FILEUTILS_RECUR);
159 *line_ptr = '/';
160 }
161 dst_stream = bb_xfopen(new_filename, "w+");
162 backup_filename = NULL;
163 } else {
164 backup_filename = xmalloc(strlen(new_filename) + 6);
165 strcpy(backup_filename, new_filename);
166 strcat(backup_filename, ".orig");
167 if (rename(new_filename, backup_filename) == -1) {
168 bb_perror_msg_and_die("Couldnt create file %s", backup_filename);
169 }
170 dst_stream = bb_xfopen(new_filename, "w");
171 }
172
173 if ((backup_filename == NULL) || file_doesnt_exist(original_filename)) {
174 src_stream = NULL;
175 } else {
176 if (strcmp(original_filename, new_filename) == 0) {
177 src_stream = bb_xfopen(backup_filename, "r");
178 } else {
179 src_stream = bb_xfopen(original_filename, "r");
180 }
181 }
182
183 printf("patching file %s\n", new_filename);
184
185 /* Handle each hunk */
186 patch_line = bb_get_line_from_file(stdin);
187 while (patch_line) {
188 unsigned int count;
189 unsigned int src_beg_line;
190 unsigned int unused;
191 unsigned int hunk_offset_start = 0;
192 int hunk_error = 0;
193
194 /* This bit should be improved */
195 if ((sscanf(patch_line, "@@ -%d,%d +%d,%d @@", &src_beg_line, &unused, &dest_beg_line, &unused) != 4) &&
196 (sscanf(patch_line, "@@ -%d,%d +%d @@", &src_beg_line, &unused, &dest_beg_line) != 3) &&
197 (sscanf(patch_line, "@@ -%d +%d,%d @@", &src_beg_line, &dest_beg_line, &unused) != 3)) {
198 /* No more hunks for this file */
199 break;
200 }
201 free(patch_line);
202 hunk_count++;
203
204 if (src_beg_line && dest_beg_line) {
205 /* Copy unmodified lines upto start of hunk */
206 /* src_beg_line will be 0 if its a new file */
207 count = src_beg_line - src_cur_line;
208 if (copy_lines(src_stream, dst_stream, count) != count) {
209 bb_error_msg_and_die("Bad src file");
210 }
211 src_cur_line += count;
212 dest_cur_line += count;
213 copy_trailing_lines_flag = 1;
214 }
215 hunk_offset_start = src_cur_line;
216
217 while ((patch_line = bb_get_line_from_file(stdin)) != NULL) {
218 if ((*patch_line == '-') || (*patch_line == ' ')) {
219 char *src_line = NULL;
220 if (src_stream) {
221 src_line = bb_get_line_from_file(src_stream);
222 if (!src_line) {
223 hunk_error++;
224 break;
225 } else {
226 src_cur_line++;
227 }
228 if (strcmp(src_line, patch_line + 1) != 0) {
229 bb_error_msg("Hunk #%d FAILED at %d.", hunk_count, hunk_offset_start);
230 hunk_error++;
231 free(patch_line);
232 break;
233 }
234 free(src_line);
235 }
236 if (*patch_line == ' ') {
237 fputs(patch_line + 1, dst_stream);
238 dest_cur_line++;
239 }
240 } else if (*patch_line == '+') {
241 fputs(patch_line + 1, dst_stream);
242 dest_cur_line++;
243 } else {
244 break;
245 }
246 free(patch_line);
247 }
248 if (hunk_error) {
249 bad_hunk_count++;
250 }
251 }
252
253 /* Cleanup last patched file */
254 if (copy_trailing_lines_flag) {
255 copy_lines(src_stream, dst_stream, -1);
256 }
257 if (src_stream) {
258 fclose(src_stream);
259 }
260 if (dst_stream) {
261 fclose(dst_stream);
262 }
263 if (bad_hunk_count) {
264 if (!ret) {
265 ret = 1;
266 }
267 bb_error_msg("%d out of %d hunk FAILED", bad_hunk_count, hunk_count);
268 } else {
269 /* It worked, we can remove the backup */
270 if (backup_filename) {
271 unlink(backup_filename);
272 }
273 if ((dest_cur_line == 0) || (dest_beg_line == 0)) {
274 /* The new patched file is empty, remove it */
275 if (unlink(new_filename) == -1) {
276 bb_perror_msg_and_die("Couldnt remove file %s", new_filename);
277 }
278 if (unlink(original_filename) == -1) {
279 bb_perror_msg_and_die("Couldnt remove original file %s", new_filename);
280 }
281 }
282 }
283 }
284
285 /* 0 = SUCCESS
286 * 1 = Some hunks failed
287 * 2 = More serious problems
288 */
289 return(ret);
290}