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 GPLv2 or later, see file LICENSE in this source tree.
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_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
,
87 xfunc_error_retval
= 2;
90 const char *i
= "-"; /* compat */
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*/
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*/
108 "dry-run\0" No_argument
"\xfd"
110 "backup-if-mismatch\0" No_argument
"\xfe" /*ignored*/
111 "no-backup-if-mismatch\0" No_argument
"\xff" /*ignored*/
114 applet_long_options
= patch_longopts
;
116 /* -f,-E,-g are ignored */
117 opt
= getopt32(argv
, "p:i:RN""fEg:", &p
, &i
, NULL
);
120 patch_level
= xatoi(p
); /* can be negative! */
121 patch_file
= xfopen_stdin(i
);
124 patch_line
= xmalloc_fgetline(patch_file
);
128 //char *old_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;
138 /* Skip everything upto the "---" marker
139 * No need to parse the lines "Only in <dir>", and "diff <args>"
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
150 new_filename
= extract_filename(patch_line
, patch_level
, "+++ ");
152 bb_error_msg_and_die("invalid patch");
155 /* Get access rights from the file to be patched */
156 if (stat(new_filename
, &saved_stat
) != 0) {
157 char *slash
= strrchr(new_filename
, '/');
159 /* Create leading directories */
161 bb_make_directory(new_filename
, -1, FILEUTILS_RECUR
);
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
);
171 src_stream
= xfopen_for_read(new_filename
);
173 if (opt
& OPT_dry_run
) {
174 dst_stream
= xfopen_for_write("/dev/null");
176 dst_stream
= xfopen_for_write(new_filename
);
177 fchmod(fileno(dst_stream
), saved_stat
.st_mode
);
180 printf("patching file %s\n", new_filename
);
182 /* Handle all hunks for this file */
183 patch_line
= xmalloc_fgets(patch_file
);
186 unsigned src_beg_line
;
187 unsigned hunk_offset_start
;
188 unsigned src_last_line
= 1;
189 unsigned dst_last_line
= 1;
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)
194 /* No more hunks for this file */
199 unsigned tmp
= src_last_line
;
200 src_last_line
= dst_last_line
;
203 src_beg_line
= dst_beg_line
;
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");
215 src_cur_line
+= count
;
216 dst_cur_line
+= count
;
217 copy_trailing_lines_flag
= 1;
219 src_last_line
+= hunk_offset_start
= src_cur_line
;
220 dst_last_line
+= dst_cur_line
;
224 patch_line
= xmalloc_fgets(patch_file
);
225 if (patch_line
== NULL
)
228 /* whitespace-damaged patch with "" lines */
230 patch_line
= xstrdup(" ");
232 if ((*patch_line
!= '-') && (*patch_line
!= '+')
233 && (*patch_line
!= ' ')
235 break; /* End of hunk */
237 if (*patch_line
!= plus
) { /* '-' or ' ' */
238 char *src_line
= NULL
;
239 if (src_cur_line
== src_last_line
)
242 src_line
= xmalloc_fgets(src_stream
);
244 int diff
= strcmp(src_line
, patch_line
+ 1);
251 /* Do not patch an already patched hunk with -N */
252 if (src_line
== 0 && (opt
& OPT_N
)) {
256 bb_error_msg("hunk #%u FAILED at %u", hunk_count
, hunk_offset_start
);
260 if (*patch_line
!= ' ') { /* '-' */
264 if (dst_cur_line
== dst_last_line
)
266 fputs(patch_line
+ 1, dst_stream
);
268 } /* end of while loop handling one hunk */
269 } /* end of while loop handling one file */
271 /* Cleanup last patched file */
272 if (copy_trailing_lines_flag
) {
273 copy_lines(src_stream
, dst_stream
, (unsigned)(-1));
279 if (bad_hunk_count
) {
281 bb_error_msg("%u out of %u hunk FAILED", bad_hunk_count
, hunk_count
);
283 /* It worked, we can remove the backup */
284 if (backup_filename
) {
285 unlink(backup_filename
);
287 if (!(opt
& OPT_dry_run
)
288 && ((dst_cur_line
== 0) || (dst_beg_line
== 0))
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);
296 free(backup_filename
);
297 //free(old_filename);
299 } /* end of "while there are patch lines" */
302 * 1 = Some hunks failed
303 * 2 = More serious problems (exited earlier)