diff options
Diffstat (limited to 'editors/patch.c')
| -rw-r--r-- | editors/patch.c | 254 |
1 files changed, 254 insertions, 0 deletions
diff --git a/editors/patch.c b/editors/patch.c new file mode 100644 index 0000000..e8482a7 --- /dev/null +++ b/editors/patch.c @@ -0,0 +1,254 @@ +/* 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 *dst_stream, unsigned lines_count) +{ + while (src_stream && lines_count) { + char *line; + line = xmalloc_fgets(src_stream); + if (line == NULL) { + break; + } + if (fputs(line, dst_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(char *line, int patch_level, const char *pat) +{ + char *temp = NULL, *filename_start_ptr = line + 4; + + if (strncmp(line, pat, 4) == 0) { + /* Terminate string at end of source filename */ + line[strcspn(line, "\t\n\r")] = '\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 UNUSED_PARAM, char **argv) +{ + struct stat saved_stat; + char *patch_line; + FILE *patch_file; + int patch_level; + int ret = 0; + char plus = '+'; + + xfunc_error_retval = 2; + { + const char *p = "-1"; + const char *i = "-"; /* compat */ + if (getopt32(argv, "p:i:R", &p, &i) & 4) + plus = '-'; + patch_level = xatoi(p); /* can be negative! */ + patch_file = xfopen_stdin(i); + } + + patch_line = xmalloc_fgetline(patch_file); + while (patch_line) { + FILE *src_stream; + FILE *dst_stream; + //char *old_filename; + char *new_filename; + char *backup_filename; + unsigned src_cur_line = 1; + unsigned dst_cur_line = 0; + unsigned dst_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>" + */ + do { + /* Extract the filename used before the patch was generated */ + new_filename = extract_filename(patch_line, patch_level, "--- "); + // was old_filename above + patch_line = xmalloc_fgetline(patch_file); + if (!patch_line) goto quit; + } while (!new_filename); + free(new_filename); // "source" filename is irrelevant + + new_filename = extract_filename(patch_line, patch_level, "+++ "); + if (!new_filename) { + bb_error_msg_and_die("invalid patch"); + } + + /* Get access rights from the file to be patched */ + if (stat(new_filename, &saved_stat) != 0) { + char *slash = strrchr(new_filename, '/'); + if (slash) { + /* Create leading directories */ + *slash = '\0'; + bb_make_directory(new_filename, -1, FILEUTILS_RECUR); + *slash = '/'; + } + backup_filename = NULL; + src_stream = NULL; + saved_stat.st_mode = 0644; + } else { + backup_filename = xasprintf("%s.orig", new_filename); + xrename(new_filename, backup_filename); + src_stream = xfopen_for_read(backup_filename); + } + dst_stream = xfopen_for_write(new_filename); + fchmod(fileno(dst_stream), saved_stat.st_mode); + + 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 hunk_offset_start; + unsigned src_last_line = 1; + unsigned dst_last_line = 1; + + if ((sscanf(patch_line, "@@ -%d,%d +%d,%d", &src_beg_line, &src_last_line, &dst_beg_line, &dst_last_line) < 3) + && (sscanf(patch_line, "@@ -%d +%d,%d", &src_beg_line, &dst_beg_line, &dst_last_line) < 2) + ) { + /* No more hunks for this file */ + break; + } + if (plus != '+') { + /* reverse patch */ + unsigned tmp = src_last_line; + src_last_line = dst_last_line; + dst_last_line = tmp; + tmp = src_beg_line; + src_beg_line = dst_beg_line; + dst_beg_line = tmp; + } + hunk_count++; + + if (src_beg_line && dst_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; + dst_cur_line += count; + copy_trailing_lines_flag = 1; + } + src_last_line += hunk_offset_start = src_cur_line; + dst_last_line += dst_cur_line; + + while (1) { + free(patch_line); + patch_line = xmalloc_fgets(patch_file); + if (patch_line == NULL) + break; /* EOF */ + if ((*patch_line != '-') && (*patch_line != '+') + && (*patch_line != ' ') + ) { + break; /* End of hunk */ + } + if (*patch_line != plus) { /* '-' or ' ' */ + char *src_line = NULL; + if (src_cur_line == src_last_line) + break; + 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 #%u FAILED at %u", hunk_count, hunk_offset_start); + bad_hunk_count++; + break; + } + if (*patch_line != ' ') { /* '-' */ + continue; + } + } + if (dst_cur_line == dst_last_line) + break; + fputs(patch_line + 1, dst_stream); + dst_cur_line++; + } /* end of while loop handling one hunk */ + } /* 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); + } + 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); + } + if ((dst_cur_line == 0) || (dst_beg_line == 0)) { + /* The new patched file is empty, remove it */ + xunlink(new_filename); + // /* old_filename and new_filename may be the same file */ + // unlink(old_filename); + } + } + free(backup_filename); + //free(old_filename); + free(new_filename); + } /* end of "while there are patch lines" */ + quit: + /* 0 = SUCCESS + * 1 = Some hunks failed + * 2 = More serious problems (exited earlier) + */ + return ret; +} |