1 /* vi: set sw=4 ts=4: */
3 * busybox patch applet to handle the unified diff format.
4 * Copyright (C) 2003 Glenn McGrath <bug1@iinet.net.au>
6 * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
8 * This applet is written to work with patches generated by GNU diff,
9 * where there is equivalent functionality busybox patch shall behave
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
18 * - Patches must apply cleanly or patch (not just one hunk) will fail.
19 * - Reject file isnt saved
26 static unsigned int copy_lines(FILE *src_stream, FILE *dest_stream, const unsigned int lines_count)
30 while (src_stream && (i < lines_count)) {
32 line = xmalloc_fgets(src_stream);
36 if (fputs(line, dest_stream) == EOF) {
37 bb_perror_msg_and_die("error writing to new file");
46 /* If patch_level is -1 it will remove all directory names
47 * char *line must be greater than 4 chars
48 * returns NULL if the file doesnt exist or error
49 * returns malloc'ed filename
52 static char *extract_filename(char *line, int patch_level)
54 char *temp, *filename_start_ptr = line + 4;
57 /* Terminate string at end of source filename */
58 temp = strchrnul(filename_start_ptr, '\t');
61 /* Skip over (patch_level) number of leading directories */
62 if (patch_level == -1)
63 patch_level = INT_MAX;
64 for (i = 0; i < patch_level; i++) {
65 temp = strchr(filename_start_ptr, '/');
68 filename_start_ptr = temp + 1;
71 return xstrdup(filename_start_ptr);
74 static int file_doesnt_exist(const char *filename)
77 return stat(filename, &statbuf);
80 int patch_main(int argc, char **argv);
81 int patch_main(int argc, char **argv)
86 FILE *patch_file = NULL;
90 ret = getopt32(argv, "p:i:", &p, &i);
92 patch_level = xatol_range(p, -1, USHRT_MAX);
94 patch_file = xfopen(i, "r");
101 patch_line = xmalloc_getline(patch_file);
105 char *original_filename;
107 char *backup_filename;
108 unsigned int src_cur_line = 1;
109 unsigned int dest_cur_line = 0;
110 unsigned int dest_beg_line;
111 unsigned int bad_hunk_count = 0;
112 unsigned int hunk_count = 0;
113 char copy_trailing_lines_flag = 0;
115 /* Skip everything upto the "---" marker
116 * No need to parse the lines "Only in <dir>", and "diff <args>"
118 while (patch_line && strncmp(patch_line, "--- ", 4) != 0) {
120 patch_line = xmalloc_getline(patch_file);
122 /* FIXME: patch_line NULL check?? */
124 /* Extract the filename used before the patch was generated */
125 original_filename = extract_filename(patch_line, patch_level);
128 patch_line = xmalloc_getline(patch_file);
129 /* FIXME: NULL check?? */
130 if (strncmp(patch_line, "+++ ", 4) != 0) {
132 bb_error_msg("invalid patch");
135 new_filename = extract_filename(patch_line, patch_level);
138 if (file_doesnt_exist(new_filename)) {
140 /* Create leading directories */
141 line_ptr = strrchr(new_filename, '/');
144 bb_make_directory(new_filename, -1, FILEUTILS_RECUR);
147 dst_stream = xfopen(new_filename, "w+");
148 backup_filename = NULL;
150 backup_filename = xmalloc(strlen(new_filename) + 6);
151 strcpy(backup_filename, new_filename);
152 strcat(backup_filename, ".orig");
153 if (rename(new_filename, backup_filename) == -1) {
154 bb_perror_msg_and_die("cannot create file %s",
157 dst_stream = xfopen(new_filename, "w");
160 if ((backup_filename == NULL) || file_doesnt_exist(original_filename)) {
163 if (strcmp(original_filename, new_filename) == 0) {
164 src_stream = xfopen(backup_filename, "r");
166 src_stream = xfopen(original_filename, "r");
170 printf("patching file %s\n", new_filename);
172 /* Handle each hunk */
173 patch_line = xmalloc_fgets(patch_file);
176 unsigned int src_beg_line;
178 unsigned int hunk_offset_start = 0;
181 /* This bit should be improved */
182 if ((sscanf(patch_line, "@@ -%d,%d +%d,%d @@", &src_beg_line, &unused, &dest_beg_line, &unused) != 4) &&
183 (sscanf(patch_line, "@@ -%d,%d +%d @@", &src_beg_line, &unused, &dest_beg_line) != 3) &&
184 (sscanf(patch_line, "@@ -%d +%d,%d @@", &src_beg_line, &dest_beg_line, &unused) != 3)) {
185 /* No more hunks for this file */
191 if (src_beg_line && dest_beg_line) {
192 /* Copy unmodified lines upto start of hunk */
193 /* src_beg_line will be 0 if its a new file */
194 count = src_beg_line - src_cur_line;
195 if (copy_lines(src_stream, dst_stream, count) != count) {
196 bb_error_msg_and_die("bad src file");
198 src_cur_line += count;
199 dest_cur_line += count;
200 copy_trailing_lines_flag = 1;
202 hunk_offset_start = src_cur_line;
204 while ((patch_line = xmalloc_fgets(patch_file)) != NULL) {
205 if ((*patch_line == '-') || (*patch_line == ' ')) {
206 char *src_line = NULL;
208 src_line = xmalloc_fgets(src_stream);
215 if (strcmp(src_line, patch_line + 1) != 0) {
216 bb_error_msg("hunk #%d FAILED at %d", hunk_count, hunk_offset_start);
219 /* Probably need to find next hunk, etc... */
220 /* but for now we just bail out */
226 if (*patch_line == ' ') {
227 fputs(patch_line + 1, dst_stream);
230 } else if (*patch_line == '+') {
231 fputs(patch_line + 1, dst_stream);
243 /* Cleanup last patched file */
244 if (copy_trailing_lines_flag) {
245 copy_lines(src_stream, dst_stream, -1);
253 if (bad_hunk_count) {
257 bb_error_msg("%d out of %d hunk FAILED", bad_hunk_count, hunk_count);
259 /* It worked, we can remove the backup */
260 if (backup_filename) {
261 unlink(backup_filename);
263 if ((dest_cur_line == 0) || (dest_beg_line == 0)) {
264 /* The new patched file is empty, remove it */
265 xunlink(new_filename);
266 if (strcmp(new_filename, original_filename) != 0)
267 xunlink(original_filename);
273 * 1 = Some hunks failed
274 * 2 = More serious problems