1 /* vi: set sw=4 ts=4: */
3 * busybox patch applet to handle the unified diff format.
4 * Copyright (C) 2003 Glenn McGrath
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
24 static unsigned copy_lines(FILE *src_stream, FILE *dst_stream, unsigned lines_count)
26 while (src_stream && lines_count) {
28 line = xmalloc_fgets(src_stream);
32 if (fputs(line, dst_stream) == EOF) {
33 bb_perror_msg_and_die("error writing to new file");
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!
47 static char *extract_filename(char *line, int patch_level, const char *pat)
49 char *temp = NULL, *filename_start_ptr = line + 4;
51 if (strncmp(line, pat, 4) == 0) {
52 /* Terminate string at end of source filename */
53 line[strcspn(line, "\t\n\r")] = '\0';
55 /* Skip over (patch_level) number of leading directories */
56 while (patch_level--) {
57 temp = strchr(filename_start_ptr, '/');
60 filename_start_ptr = temp + 1;
62 temp = xstrdup(filename_start_ptr);
68 int patch_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
69 int patch_main(int argc UNUSED_PARAM, char **argv)
71 struct stat saved_stat;
81 OPT_dry_run = (1 << 4) * ENABLE_LONG_OPTS,
84 xfunc_error_retval = 2;
87 const char *i = "-"; /* compat */
89 static const char patch_longopts[] ALIGN1 =
90 "strip\0" Required_argument "p"
91 "input\0" Required_argument "i"
92 "reverse\0" No_argument "R"
93 "forward\0" No_argument "N"
94 "dry-run\0" No_argument "\xff"
96 applet_long_options = patch_longopts;
98 opt = getopt32(argv, "p:i:RN", &p, &i);
101 patch_level = xatoi(p); /* can be negative! */
102 patch_file = xfopen_stdin(i);
105 patch_line = xmalloc_fgetline(patch_file);
109 //char *old_filename;
111 char *backup_filename = NULL;
112 unsigned src_cur_line = 1;
113 unsigned dst_cur_line = 0;
114 unsigned dst_beg_line;
115 unsigned bad_hunk_count = 0;
116 unsigned hunk_count = 0;
117 smallint copy_trailing_lines_flag = 0;
119 /* Skip everything upto the "---" marker
120 * No need to parse the lines "Only in <dir>", and "diff <args>"
123 /* Extract the filename used before the patch was generated */
124 new_filename = extract_filename(patch_line, patch_level, "--- ");
125 // was old_filename above
126 patch_line = xmalloc_fgetline(patch_file);
127 if (!patch_line) goto quit;
128 } while (!new_filename);
129 free(new_filename); // "source" filename is irrelevant
131 new_filename = extract_filename(patch_line, patch_level, "+++ ");
133 bb_error_msg_and_die("invalid patch");
136 /* Get access rights from the file to be patched */
137 if (stat(new_filename, &saved_stat) != 0) {
138 char *slash = strrchr(new_filename, '/');
140 /* Create leading directories */
142 bb_make_directory(new_filename, -1, FILEUTILS_RECUR);
146 saved_stat.st_mode = 0644;
147 } else if (!(opt & OPT_dry_run)) {
148 backup_filename = xasprintf("%s.orig", new_filename);
149 xrename(new_filename, backup_filename);
150 src_stream = xfopen_for_read(backup_filename);
152 src_stream = xfopen_for_read(new_filename);
154 if (opt & OPT_dry_run) {
155 dst_stream = xfopen_for_write("/dev/null");
157 dst_stream = xfopen_for_write(new_filename);
158 fchmod(fileno(dst_stream), saved_stat.st_mode);
161 printf("patching file %s\n", new_filename);
163 /* Handle all hunks for this file */
164 patch_line = xmalloc_fgets(patch_file);
167 unsigned src_beg_line;
168 unsigned hunk_offset_start;
169 unsigned src_last_line = 1;
170 unsigned dst_last_line = 1;
172 if ((sscanf(patch_line, "@@ -%d,%d +%d,%d", &src_beg_line, &src_last_line, &dst_beg_line, &dst_last_line) < 3)
173 && (sscanf(patch_line, "@@ -%d +%d,%d", &src_beg_line, &dst_beg_line, &dst_last_line) < 2)
175 /* No more hunks for this file */
180 unsigned tmp = src_last_line;
181 src_last_line = dst_last_line;
184 src_beg_line = dst_beg_line;
189 if (src_beg_line && dst_beg_line) {
190 /* Copy unmodified lines upto start of hunk */
191 /* src_beg_line will be 0 if it's a new file */
192 count = src_beg_line - src_cur_line;
193 if (copy_lines(src_stream, dst_stream, count)) {
194 bb_error_msg_and_die("bad src file");
196 src_cur_line += count;
197 dst_cur_line += count;
198 copy_trailing_lines_flag = 1;
200 src_last_line += hunk_offset_start = src_cur_line;
201 dst_last_line += dst_cur_line;
205 patch_line = xmalloc_fgets(patch_file);
206 if (patch_line == NULL)
209 /* whitespace-damaged patch with "" lines */
211 patch_line = xstrdup(" ");
213 if ((*patch_line != '-') && (*patch_line != '+')
214 && (*patch_line != ' ')
216 break; /* End of hunk */
218 if (*patch_line != plus) { /* '-' or ' ' */
219 char *src_line = NULL;
220 if (src_cur_line == src_last_line)
223 src_line = xmalloc_fgets(src_stream);
225 int diff = strcmp(src_line, patch_line + 1);
232 /* Do not patch an already patched hunk with -N */
233 if (src_line == 0 && (opt & OPT_N)) {
237 bb_error_msg("hunk #%u FAILED at %u", hunk_count, hunk_offset_start);
241 if (*patch_line != ' ') { /* '-' */
245 if (dst_cur_line == dst_last_line)
247 fputs(patch_line + 1, dst_stream);
249 } /* end of while loop handling one hunk */
250 } /* end of while loop handling one file */
252 /* Cleanup last patched file */
253 if (copy_trailing_lines_flag) {
254 copy_lines(src_stream, dst_stream, (unsigned)(-1));
260 if (bad_hunk_count) {
262 bb_error_msg("%u out of %u hunk FAILED", bad_hunk_count, hunk_count);
264 /* It worked, we can remove the backup */
265 if (backup_filename) {
266 unlink(backup_filename);
268 if (!(opt & OPT_dry_run)
269 && ((dst_cur_line == 0) || (dst_beg_line == 0))
271 /* The new patched file is empty, remove it */
272 xunlink(new_filename);
273 // /* old_filename and new_filename may be the same file */
274 // unlink(old_filename);
277 free(backup_filename);
278 //free(old_filename);
280 } /* end of "while there are patch lines" */
283 * 1 = Some hunks failed
284 * 2 = More serious problems (exited earlier)