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 *dest_stream, unsigned lines_count)
26 while (src_stream && lines_count) {
28 line = xmalloc_fgets(src_stream);
32 if (fputs(line, dest_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 ATTRIBUTE_UNUSED, char **argv)
71 struct stat saved_stat;
77 xfunc_error_retval = 2;
80 const char *i = "-"; /* compat */
81 getopt32(argv, "p:i:", &p, &i);
82 patch_level = xatoi(p); /* can be negative! */
83 patch_file = xfopen_stdin(i);
86 patch_line = xmalloc_getline(patch_file);
92 char *backup_filename;
93 unsigned src_cur_line = 1;
94 unsigned dest_cur_line = 0;
95 unsigned dest_beg_line;
96 unsigned bad_hunk_count = 0;
97 unsigned hunk_count = 0;
98 smallint copy_trailing_lines_flag = 0;
100 /* Skip everything upto the "---" marker
101 * No need to parse the lines "Only in <dir>", and "diff <args>"
104 /* Extract the filename used before the patch was generated */
105 new_filename = extract_filename(patch_line, patch_level, "--- ");
106 // was old_filename above
107 patch_line = xmalloc_getline(patch_file);
108 if (!patch_line) goto quit;
109 } while (!new_filename);
110 free(new_filename); // "source" filename is irrelevant
112 new_filename = extract_filename(patch_line, patch_level, "+++ ");
114 bb_error_msg_and_die("invalid patch");
117 /* Get access rights from the file to be patched */
118 if (stat(new_filename, &saved_stat) != 0) {
119 char *slash = strrchr(new_filename, '/');
121 /* Create leading directories */
123 bb_make_directory(new_filename, -1, FILEUTILS_RECUR);
126 backup_filename = NULL;
128 saved_stat.st_mode = 0644;
130 backup_filename = xasprintf("%s.orig", new_filename);
131 xrename(new_filename, backup_filename);
132 src_stream = xfopen(backup_filename, "r");
134 dst_stream = xfopen(new_filename, "w");
135 fchmod(fileno(dst_stream), saved_stat.st_mode);
137 printf("patching file %s\n", new_filename);
139 /* Handle all hunks for this file */
140 patch_line = xmalloc_fgets(patch_file);
143 unsigned src_beg_line;
144 unsigned hunk_offset_start;
145 unsigned src_last_line = 1;
147 if ((sscanf(patch_line, "@@ -%d,%d +%d", &src_beg_line, &src_last_line, &dest_beg_line) != 3)
148 && (sscanf(patch_line, "@@ -%d +%d", &src_beg_line, &dest_beg_line) != 2)
149 ) { /* No more hunks for this file */
154 if (src_beg_line && dest_beg_line) {
155 /* Copy unmodified lines upto start of hunk */
156 /* src_beg_line will be 0 if it's a new file */
157 count = src_beg_line - src_cur_line;
158 if (copy_lines(src_stream, dst_stream, count)) {
159 bb_error_msg_and_die("bad src file");
161 src_cur_line += count;
162 dest_cur_line += count;
163 copy_trailing_lines_flag = 1;
165 src_last_line += hunk_offset_start = src_cur_line;
169 patch_line = xmalloc_fgets(patch_file);
170 if (patch_line == NULL)
172 if ((*patch_line != '-') && (*patch_line != '+')
173 && (*patch_line != ' ')
175 break; /* End of hunk */
177 if (*patch_line != '+') { /* '-', ' ' or '\n' */
178 char *src_line = NULL;
179 if (src_cur_line == src_last_line)
182 src_line = xmalloc_fgets(src_stream);
184 int diff = strcmp(src_line, patch_line + 1);
187 if (diff) src_line = NULL;
191 bb_error_msg("hunk #%u FAILED at %u", hunk_count, hunk_offset_start);
195 if (*patch_line == '-') {
199 fputs(patch_line + 1, dst_stream);
201 } /* end of while loop handling one hunk */
202 } /* end of while loop handling one file */
204 /* Cleanup last patched file */
205 if (copy_trailing_lines_flag) {
206 copy_lines(src_stream, dst_stream, (unsigned)(-1));
212 if (bad_hunk_count) {
214 bb_error_msg("%u out of %u hunk FAILED", bad_hunk_count, hunk_count);
216 /* It worked, we can remove the backup */
217 if (backup_filename) {
218 unlink(backup_filename);
220 if ((dest_cur_line == 0) || (dest_beg_line == 0)) {
221 /* The new patched file is empty, remove it */
222 xunlink(new_filename);
223 // /* old_filename and new_filename may be the same file */
224 // unlink(old_filename);
227 free(backup_filename);
228 //free(old_filename);
230 } /* end of "while there are patch lines" */
234 * 1 = Some hunks failed
235 * 2 = More serious problems (exited earlier)