/* vi: set sw=4 ts=4: */
/*
* busybox patch applet to handle the unified diff format.
* Copyright (C) 2003 Glenn McGrath
*
* 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 "libbb.h"
static unsigned copy_lines(FILE *src_stream, FILE *dest_stream, unsigned lines_count)
{
while (src_stream && 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);
lines_count--;
}
return lines_count;
}
/* 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
* NB: frees 1st argument!
*/
static char *extract_filename_and_free_line(char *line, int patch_level)
{
char *temp, *filename_start_ptr = line + 4;
/* Terminate string at end of source filename */
temp = strchrnul(filename_start_ptr, '\t');
*temp = '\0';
/* Skip over (patch_level) number of leading directories */
while (patch_level--) {
temp = strchr(filename_start_ptr, '/');
if (!temp)
break;
filename_start_ptr = temp + 1;
}
temp = xstrdup(filename_start_ptr);
free(line);
return temp;
}
int patch_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int patch_main(int argc ATTRIBUTE_UNUSED, char **argv)
{
struct stat saved_stat;
char *patch_line;
FILE *patch_file;
int patch_level;
int ret = 0;
xfunc_error_retval = 2;
{
const char *p = "-1";
const char *i = "-"; /* compat */
getopt32(argv, "p:i:", &p, &i);
patch_level = xatoi(p); /* can be negative! */
patch_file = xfopen_stdin(i);
}
patch_line = xmalloc_getline(patch_file);
while (patch_line) {
FILE *src_stream;
FILE *dst_stream;
char *original_filename;
char *new_filename;
char *backup_filename;
unsigned src_cur_line = 1;
unsigned dest_cur_line = 0;
unsigned dest_beg_line;
unsigned bad_hunk_count = 0;
unsigned hunk_count = 0;
smallint copy_trailing_lines_flag = 0;
/* Skip everything upto the "---" marker
* No need to parse the lines "Only in <dir>", and "diff <args>"
*/
while (strncmp(patch_line, "--- ", 4) != 0) {
free(patch_line);
patch_line = xmalloc_getline(patch_file);
if (!patch_line)
bb_error_msg_and_die("invalid patch");
}
/* Extract the filename used before the patch was generated */
original_filename = extract_filename_and_free_line(patch_line, patch_level);
patch_line = xmalloc_getline(patch_file);
if (!patch_line || strncmp(patch_line, "+++ ", 4) != 0)
bb_error_msg_and_die("invalid patch");
new_filename = extract_filename_and_free_line(patch_line, patch_level);
/* Get access rights from the file to be patched, -1 file does not exist */
if (stat(new_filename, &saved_stat) != 0) {
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 = '/';
}
backup_filename = NULL;
saved_stat.st_mode = 0644;
} else {
backup_filename = xasprintf("%s.orig", new_filename);
xrename(new_filename, backup_filename);
}
dst_stream = xfopen(new_filename, "w");
fchmod(fileno(dst_stream), saved_stat.st_mode);
src_stream = NULL;
if (backup_filename && !stat(original_filename, &saved_stat)) {
src_stream = xfopen((strcmp(original_filename, new_filename)) ?
original_filename : backup_filename, "r");
}
printf("patching file %s\n", new_filename);
/* Handle all hunks for this file */
patch_line = xmalloc_fgets(patch_file);
while (patch_line) {
unsigned count;
unsigned src_beg_line;
unsigned unused;
unsigned hunk_offset_start = 0;
smallint 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;
}
hunk_count++;
if (src_beg_line && dest_beg_line) {
/* Copy unmodified lines upto start of hunk */
/* src_beg_line will be 0 if it's a new file */
count = src_beg_line - src_cur_line;
if (copy_lines(src_stream, dst_stream, 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 (1) {
free(patch_line);
patch_line = xmalloc_fgets(patch_file);
if (patch_line == NULL) break;
if ((*patch_line == '-') || (*patch_line == ' ')) {
char *src_line = NULL;
if (src_stream) {
src_line = xmalloc_fgets(src_stream);
if (src_line) {
int diff = strcmp(src_line, patch_line + 1);
src_cur_line++;
free(src_line);
if (diff) src_line = NULL;
}
if (!src_line) {
bb_error_msg("hunk #%d FAILED at %d", hunk_count, hunk_offset_start);
hunk_error = 1;
break;
}
}
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;
}
} /* end of while loop handling one hunk */
if (hunk_error) {
bad_hunk_count++;
}
} /* end of while loop handling one file */
/* Cleanup last patched file */
if (copy_trailing_lines_flag) {
copy_lines(src_stream, dst_stream, (unsigned)(-1));
}
if (src_stream) {
fclose(src_stream);
}
if (dst_stream) {
fclose(dst_stream);
}
if (bad_hunk_count) {
ret = 1;
bb_error_msg("%u out of %u hunk FAILED", bad_hunk_count, hunk_count);
} else {
/* It worked, we can remove the backup */
if (backup_filename) {
unlink(backup_filename);
free(backup_filename);
}
if ((dest_cur_line == 0) || (dest_beg_line == 0)) {
/* The new patched file is empty, remove it */
xunlink(new_filename);
if (strcmp(new_filename, original_filename) != 0)
xunlink(original_filename);
}
}
} /* end of "while there are patch lines" */
/* 0 = SUCCESS
* 1 = Some hunks failed
* 2 = More serious problems (exited earlier)
*/
return ret;
}