busybox/editors/patch.c

/* vi: set sw=4 ts=4: */
/*
 *  busybox patch applet to handle the unified diff format.
 *  Copyright (C) 2003 Glenn McGrath <bug1@iinet.net.au>
 *
 *  Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
 *
 *  This applet is written to work with patches generated by GNU diff,
 *  where there is equivalent functionality busybox patch shall behave
 *  as per GNU patch.
 *
 *  There is a SUSv3 specification for patch, however it looks to be
 *  incomplete, it doesnt even mention unified diff format.
 *  http://www.opengroup.org/onlinepubs/007904975/utilities/patch.html
 *
 *  Issues
 *   - Non-interactive
 *   - Patches must apply cleanly or patch (not just one hunk) will fail.
 *   - Reject file isnt saved
 */

#include <getopt.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include "busybox.h"

static unsigned int copy_lines(FILE *src_stream, FILE *dest_stream, const unsigned int lines_count)
{
	unsigned int i = 0;

	while (src_stream && (i < lines_count)) {
		char *line;
		line = xmalloc_fgets(src_stream);
		if (line == NULL) {
			break;
		}
		if (fputs(line, dest_stream) == EOF) {
			bb_perror_msg_and_die("error writing to new file");
		}
		free(line);

		i++;
	}
	return i;
}

/* If patch_level is -1 it will remove all directory names
 * char *line must be greater than 4 chars
 * returns NULL if the file doesnt exist or error
 * returns malloc'ed filename
 */

static char *extract_filename(char *line, int patch_level)
{
	char *temp, *filename_start_ptr = line + 4;
	int i;

	/* Terminate string at end of source filename */
	temp = strchr(filename_start_ptr, '\t');
	if (temp) *temp = 0;

	/* skip over (patch_level) number of leading directories */
	for (i = 0; i < patch_level; i++) {
		if(!(temp = strchr(filename_start_ptr, '/'))) break;
		filename_start_ptr = temp + 1;
	}

	return xstrdup(filename_start_ptr);
}

static int file_doesnt_exist(const char *filename)
{
	struct stat statbuf;
	return stat(filename, &statbuf);
}

int patch_main(int argc, char **argv)
{
	int patch_level = -1;
	char *patch_line;
	int ret;
	FILE *patch_file = NULL;

	{
		char *p, *i;
		ret = getopt32(argc, argv, "p:i:", &p, &i);
		if (ret & 1)
			patch_level = xatol_range(p, -1, USHRT_MAX);
		if (ret & 2) {
			patch_file = xfopen(i, "r");
		} else {
			patch_file = stdin;
		}
		ret = 0;
	}

	patch_line = xmalloc_fgets(patch_file);
	while (patch_line) {
		FILE *src_stream;
		FILE *dst_stream;
		char *original_filename;
		char *new_filename;
		char *backup_filename;
		unsigned int src_cur_line = 1;
		unsigned int dest_cur_line = 0;
		unsigned int dest_beg_line;
		unsigned int bad_hunk_count = 0;
		unsigned int hunk_count = 0;
		char copy_trailing_lines_flag = 0;

		/* Skip everything upto the "---" marker
		 * No need to parse the lines "Only in <dir>", and "diff <args>"
		 */
		while (patch_line && strncmp(patch_line, "--- ", 4) != 0) {
			free(patch_line);
			patch_line = xmalloc_fgets(patch_file);
		}
		/* FIXME: patch_line NULL check?? */

		/* Extract the filename used before the patch was generated */
		original_filename = extract_filename(patch_line, patch_level);
		free(patch_line);

		patch_line = xmalloc_fgets(patch_file);
		/* FIXME: NULL check?? */
		if (strncmp(patch_line, "+++ ", 4) != 0) {
			ret = 2;
			bb_error_msg("invalid patch");
			continue;
		}
		new_filename = extract_filename(patch_line, patch_level);
		free(patch_line);

		if (file_doesnt_exist(new_filename)) {
			char *line_ptr;
			/* Create leading directories */
			line_ptr = strrchr(new_filename, '/');
			if (line_ptr) {
				*line_ptr = '\0';
				bb_make_directory(new_filename, -1, FILEUTILS_RECUR);
				*line_ptr = '/';
			}
			dst_stream = xfopen(new_filename, "w+");
			backup_filename = NULL;
		} else {
			backup_filename = xmalloc(strlen(new_filename) + 6);
			strcpy(backup_filename, new_filename);
			strcat(backup_filename, ".orig");
			if (rename(new_filename, backup_filename) == -1) {
				bb_perror_msg_and_die("cannot create file %s",
						backup_filename);
			}
			dst_stream = xfopen(new_filename, "w");
		}

		if ((backup_filename == NULL) || file_doesnt_exist(original_filename)) {
			src_stream = NULL;
		} else {
			if (strcmp(original_filename, new_filename) == 0) {
				src_stream = xfopen(backup_filename, "r");
			} else {
				src_stream = xfopen(original_filename, "r");
			}
		}

		printf("patching file %s\n", new_filename);

		/* Handle each hunk */
		patch_line = xmalloc_fgets(patch_file);
		while (patch_line) {
			unsigned int count;
			unsigned int src_beg_line;
			unsigned int unused;
			unsigned int hunk_offset_start = 0;
			int hunk_error = 0;

			/* This bit should be improved */
			if ((sscanf(patch_line, "@@ -%d,%d +%d,%d @@", &src_beg_line, &unused, &dest_beg_line, &unused) != 4) &&
				(sscanf(patch_line, "@@ -%d,%d +%d @@", &src_beg_line, &unused, &dest_beg_line) != 3) &&
				(sscanf(patch_line, "@@ -%d +%d,%d @@", &src_beg_line, &dest_beg_line, &unused) != 3)) {
				/* No more hunks for this file */
				break;
			}
			free(patch_line);
			hunk_count++;

			if (src_beg_line && dest_beg_line) {
				/* Copy unmodified lines upto start of hunk */
				/* src_beg_line will be 0 if its a new file */
				count = src_beg_line - src_cur_line;
				if (copy_lines(src_stream, dst_stream, count) != count) {
					bb_error_msg_and_die("bad src file");
				}
				src_cur_line += count;
				dest_cur_line += count;
				copy_trailing_lines_flag = 1;
			}
			hunk_offset_start = src_cur_line;

			while ((patch_line = xmalloc_fgets(patch_file)) != NULL) {
				if ((*patch_line == '-') || (*patch_line == ' ')) {
					char *src_line = NULL;
					if (src_stream) {
						src_line = xmalloc_fgets(src_stream);
						if (!src_line) {
							hunk_error++;
							break;
						} else {
							src_cur_line++;
						}
						if (strcmp(src_line, patch_line + 1) != 0) {
							bb_error_msg("hunk #%d FAILED at %d", hunk_count, hunk_offset_start);
							hunk_error++;
							free(patch_line);
							/* Probably need to find next hunk, etc... */
							/* but for now we just bail out */
							patch_line = NULL;
							break;
						}
						free(src_line);
					}
					if (*patch_line == ' ') {
						fputs(patch_line + 1, dst_stream);
						dest_cur_line++;
					}
				} else if (*patch_line == '+') {
					fputs(patch_line + 1, dst_stream);
					dest_cur_line++;
				} else {
					break;
				}
				free(patch_line);
			}
			if (hunk_error) {
				bad_hunk_count++;
			}
		}

		/* Cleanup last patched file */
		if (copy_trailing_lines_flag) {
			copy_lines(src_stream, dst_stream, -1);
		}
		if (src_stream) {
			fclose(src_stream);
		}
		if (dst_stream) {
			fclose(dst_stream);
		}
		if (bad_hunk_count) {
			if (!ret) {
				ret = 1;
			}
			bb_error_msg("%d out of %d hunk FAILED", bad_hunk_count, hunk_count);
		} else {
			/* It worked, we can remove the backup */
			if (backup_filename) {
				unlink(backup_filename);
			}
			if ((dest_cur_line == 0) || (dest_beg_line == 0)) {
				/* The new patched file is empty, remove it */
				if (unlink(new_filename) == -1) {
					bb_perror_msg_and_die("cannot remove file %s", new_filename);
				}
				if (unlink(original_filename) == -1) {
					bb_perror_msg_and_die("cannot remove original file %s", new_filename);
				}
			}
		}
	}

	/* 0 = SUCCESS
	 * 1 = Some hunks failed
	 * 2 = More serious problems
	 */
	return ret;
}
1	/* vi: set sw=4 ts=4: */
2	/*
3	* busybox patch applet to handle the unified diff format.
4	* Copyright (C) 2003 Glenn McGrath <bug1@iinet.net.au>
5	*
6	* Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
7	*
8	* This applet is written to work with patches generated by GNU diff,
9	* where there is equivalent functionality busybox patch shall behave
10	* as per GNU patch.
11	*
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
15	*
16	* Issues
17	* - Non-interactive
18	* - Patches must apply cleanly or patch (not just one hunk) will fail.
19	* - Reject file isnt saved
20	*/
21
22	#include <getopt.h>
23	#include <string.h>
24	#include <stdlib.h>
25	#include <unistd.h>
26	#include "busybox.h"
27
28	static unsigned int copy_lines(FILE src_stream, FILE dest_stream, const unsigned int lines_count)
29	{
30	unsigned int i = 0;
31
32	while (src_stream && (i < lines_count)) {
33	char *line;
34	line = xmalloc_fgets(src_stream);
35	if (line == NULL) {
36	break;
37	}
38	if (fputs(line, dest_stream) == EOF) {
39	bb_perror_msg_and_die("error writing to new file");
40	}
41	free(line);
42
43	i++;
44	}
45	return i;
46	}
47
48	/* If patch_level is -1 it will remove all directory names
49	* char *line must be greater than 4 chars
50	* returns NULL if the file doesnt exist or error
51	* returns malloc'ed filename
52	*/
53
54	static char extract_filename(char line, int patch_level)
55	{
56	char temp, filename_start_ptr = line + 4;
57	int i;
58
59	/* Terminate string at end of source filename */
60	temp = strchr(filename_start_ptr, '\t');
61	if (temp) *temp = 0;
62
63	/* skip over (patch_level) number of leading directories */
64	for (i = 0; i < patch_level; i++) {
65	if(!(temp = strchr(filename_start_ptr, '/'))) break;
66	filename_start_ptr = temp + 1;
67	}
68
69	return xstrdup(filename_start_ptr);
70	}
71
72	static int file_doesnt_exist(const char *filename)
73	{
74	struct stat statbuf;
75	return stat(filename, &statbuf);
76	}
77
78	int patch_main(int argc, char **argv)
79	{
80	int patch_level = -1;
81	char *patch_line;
82	int ret;
83	FILE *patch_file = NULL;
84
85	{
86	char p, i;
87	ret = getopt32(argc, argv, "p:i:", &p, &i);
88	if (ret & 1)
89	patch_level = xatol_range(p, -1, USHRT_MAX);
90	if (ret & 2) {
91	patch_file = xfopen(i, "r");
92	} else {
93	patch_file = stdin;
94	}
95	ret = 0;
96	}
97
98	patch_line = xmalloc_fgets(patch_file);
99	while (patch_line) {
100	FILE *src_stream;
101	FILE *dst_stream;
102	char *original_filename;
103	char *new_filename;
104	char *backup_filename;
105	unsigned int src_cur_line = 1;
106	unsigned int dest_cur_line = 0;
107	unsigned int dest_beg_line;
108	unsigned int bad_hunk_count = 0;
109	unsigned int hunk_count = 0;
110	char copy_trailing_lines_flag = 0;
111
112	/* Skip everything upto the "---" marker
113	* No need to parse the lines "Only in <dir>", and "diff <args>"
114	*/
115	while (patch_line && strncmp(patch_line, "--- ", 4) != 0) {
116	free(patch_line);
117	patch_line = xmalloc_fgets(patch_file);
118	}
119	/* FIXME: patch_line NULL check?? */
120
121	/* Extract the filename used before the patch was generated */
122	original_filename = extract_filename(patch_line, patch_level);
123	free(patch_line);
124
125	patch_line = xmalloc_fgets(patch_file);
126	/* FIXME: NULL check?? */
127	if (strncmp(patch_line, "+++ ", 4) != 0) {
128	ret = 2;
129	bb_error_msg("invalid patch");
130	continue;
131	}
132	new_filename = extract_filename(patch_line, patch_level);
133	free(patch_line);
134
135	if (file_doesnt_exist(new_filename)) {
136	char *line_ptr;
137	/* Create leading directories */
138	line_ptr = strrchr(new_filename, '/');
139	if (line_ptr) {
140	*line_ptr = '\0';
141	bb_make_directory(new_filename, -1, FILEUTILS_RECUR);
142	*line_ptr = '/';
143	}
144	dst_stream = xfopen(new_filename, "w+");
145	backup_filename = NULL;
146	} else {
147	backup_filename = xmalloc(strlen(new_filename) + 6);
148	strcpy(backup_filename, new_filename);
149	strcat(backup_filename, ".orig");
150	if (rename(new_filename, backup_filename) == -1) {
151	bb_perror_msg_and_die("cannot create file %s",
152	backup_filename);
153	}
154	dst_stream = xfopen(new_filename, "w");
155	}
156
157	if ((backup_filename == NULL) \|\| file_doesnt_exist(original_filename)) {
158	src_stream = NULL;
159	} else {
160	if (strcmp(original_filename, new_filename) == 0) {
161	src_stream = xfopen(backup_filename, "r");
162	} else {
163	src_stream = xfopen(original_filename, "r");
164	}
165	}
166
167	printf("patching file %s\n", new_filename);
168
169	/* Handle each hunk */
170	patch_line = xmalloc_fgets(patch_file);
171	while (patch_line) {
172	unsigned int count;
173	unsigned int src_beg_line;
174	unsigned int unused;
175	unsigned int hunk_offset_start = 0;
176	int hunk_error = 0;
177
178	/* This bit should be improved */
179	if ((sscanf(patch_line, "@@ -%d,%d +%d,%d @@", &src_beg_line, &unused, &dest_beg_line, &unused) != 4) &&
180	(sscanf(patch_line, "@@ -%d,%d +%d @@", &src_beg_line, &unused, &dest_beg_line) != 3) &&
181	(sscanf(patch_line, "@@ -%d +%d,%d @@", &src_beg_line, &dest_beg_line, &unused) != 3)) {
182	/* No more hunks for this file */
183	break;
184	}
185	free(patch_line);
186	hunk_count++;
187
188	if (src_beg_line && dest_beg_line) {
189	/* Copy unmodified lines upto start of hunk */
190	/* src_beg_line will be 0 if its a new file */
191	count = src_beg_line - src_cur_line;
192	if (copy_lines(src_stream, dst_stream, count) != count) {
193	bb_error_msg_and_die("bad src file");
194	}
195	src_cur_line += count;
196	dest_cur_line += count;
197	copy_trailing_lines_flag = 1;
198	}
199	hunk_offset_start = src_cur_line;
200
201	while ((patch_line = xmalloc_fgets(patch_file)) != NULL) {
202	if ((patch_line == '-') \|\| (patch_line == ' ')) {
203	char *src_line = NULL;
204	if (src_stream) {
205	src_line = xmalloc_fgets(src_stream);
206	if (!src_line) {
207	hunk_error++;
208	break;
209	} else {
210	src_cur_line++;
211	}
212	if (strcmp(src_line, patch_line + 1) != 0) {
213	bb_error_msg("hunk #%d FAILED at %d", hunk_count, hunk_offset_start);
214	hunk_error++;
215	free(patch_line);
216	/* Probably need to find next hunk, etc... */
217	/* but for now we just bail out */
218	patch_line = NULL;
219	break;
220	}
221	free(src_line);
222	}
223	if (*patch_line == ' ') {
224	fputs(patch_line + 1, dst_stream);
225	dest_cur_line++;
226	}
227	} else if (*patch_line == '+') {
228	fputs(patch_line + 1, dst_stream);
229	dest_cur_line++;
230	} else {
231	break;
232	}
233	free(patch_line);
234	}
235	if (hunk_error) {
236	bad_hunk_count++;
237	}
238	}
239
240	/* Cleanup last patched file */
241	if (copy_trailing_lines_flag) {
242	copy_lines(src_stream, dst_stream, -1);
243	}
244	if (src_stream) {
245	fclose(src_stream);
246	}
247	if (dst_stream) {
248	fclose(dst_stream);
249	}
250	if (bad_hunk_count) {
251	if (!ret) {
252	ret = 1;
253	}
254	bb_error_msg("%d out of %d hunk FAILED", bad_hunk_count, hunk_count);
255	} else {
256	/* It worked, we can remove the backup */
257	if (backup_filename) {
258	unlink(backup_filename);
259	}
260	if ((dest_cur_line == 0) \|\| (dest_beg_line == 0)) {
261	/* The new patched file is empty, remove it */
262	if (unlink(new_filename) == -1) {
263	bb_perror_msg_and_die("cannot remove file %s", new_filename);
264	}
265	if (unlink(original_filename) == -1) {
266	bb_perror_msg_and_die("cannot remove original file %s", new_filename);
267	}
268	}
269	}
270	}
271
272	/* 0 = SUCCESS
273	* 1 = Some hunks failed
274	* 2 = More serious problems
275	*/
276	return ret;
277	}