diff options
Diffstat (limited to 'editors/patch.c')
| -rw-r--r-- | editors/patch.c | 275 |
1 files changed, 275 insertions, 0 deletions
diff --git a/editors/patch.c b/editors/patch.c new file mode 100644 index 000000000..8e885d06e --- /dev/null +++ b/editors/patch.c @@ -0,0 +1,275 @@ +/* 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 the 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); + 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; +} |