| blob | 054c9827a7988c65b953fb98f8a3110fc54e6dbc |
4 <head>
9 /* Debug borders */
11 /*
12 border: 1px solid red;
13 */
14 }
16 body {
18 }
20 a {
23 }
26 }
28 em {
31 }
33 strong {
36 }
38 tt {
40 }
48 }
52 }
53 h2 {
55 }
56 h3 {
58 }
59 h3 + * {
61 }
66 }
68 hr {
70 }
72 p {
75 }
79 }
81 pre {
84 }
86 span#author {
91 }
92 span#email {
93 }
96 }
98 div#footer {
104 }
105 div#footer-text {
108 }
109 div#footer-badges {
112 }
114 div#preamble {
117 }
123 }
127 }
131 }
133 /* Block element titles. */
141 }
144 }
148 }
151 }
154 }
160 }
166 }
171 }
175 }
180 }
183 }
187 }
188 /* DEPRECATED: Pre version 8.2.7 verse style literal block. */
191 }
200 }
204 }
209 }
215 dl {
218 }
219 dt {
224 }
227 }
231 }
234 }
237 }
240 }
243 }
246 }
253 }
257 }
258 thead {
261 }
262 tfoot {
264 }
267 }
270 }
271 /* Because the table frame attribute is overriden by CSS in most browsers. */
274 }
278 }
282 }
288 }
291 }
294 }
300 }
303 }
307 }
311 }
315 }
317 div#toctitle {
324 }
329 }
333 }
337 }
341 }
342 /* Overrides for manpage documents */
343 h1 {
348 }
349 h2 {
351 }
354 }
358 }
360 /* Workarounds for IE6's broken and incomplete CSS2. */
366 }
373 }
379 }
384 }
388 }
392 }
397 }
399 /* IE6 sets dynamically generated links as visited. */
401 </style>
402 </head>
403 <body>
405 <h1>
406 gitdiffcore(7) Manual Page
407 </h1>
410 <p>gitdiffcore -
411 Tweaking diff output
412 </p>
413 </div>
414 </div>
418 </div>
421 <div class="paragraph"><p>The diff commands <em>git diff-index</em>, <em>git diff-files</em>, and <em>git diff-tree</em>
422 can be told to manipulate differences they find in
424 is collectively called "diffcore transformation". This short note
426 that is easier to understand than the conventional kind.</p></div>
427 </div>
430 <div class="paragraph"><p>The <em>git diff-*</em> family works by first comparing two sets of
431 files:</p></div>
433 <li>
434 <p>
438 used);
439 </p>
440 </li>
441 <li>
442 <p>
444 working directory;
445 </p>
446 </li>
447 <li>
448 <p>
450 </p>
451 </li>
452 </ul></div>
454 the two sets of files by any pathspecs given on their command-lines,
455 and compare corresponding paths in the two resulting sets of files.</p></div>
456 <div class="paragraph"><p>The pathspecs are used to limit the world diff operates in. They remove
457 the filepairs outside the specified sets of pathnames. E.g. If the
458 input set of filepairs included:</p></div>
462 </div></div>
463 <div class="paragraph"><p>but the command invocation was <tt>git diff-files myfile</tt>, then the
464 junkfile entry would be removed from the list because only "myfile"
465 is under consideration.</p></div>
467 internally called "diffcore", in a format similar to what is output
468 when the -p option is not used. E.g.</p></div>
475 </div></div>
477 (each of which is called "filepair", although at this point each
478 of them talks about a single file), and transforms such a list
481 <li>
482 <p>
483 diffcore-break
484 </p>
485 </li>
486 <li>
487 <p>
488 diffcore-rename
489 </p>
490 </li>
491 <li>
492 <p>
493 diffcore-merge-broken
494 </p>
495 </li>
496 <li>
497 <p>
498 diffcore-pickaxe
499 </p>
500 </li>
501 <li>
502 <p>
503 diffcore-order
504 </p>
505 </li>
506 </ul></div>
507 <div class="paragraph"><p>These are applied in sequence. The set of filepairs <em>git diff-*</em>
508 commands find are used as the input to diffcore-break, and
509 the output from diffcore-break is used as the input to the
510 next transformation. The final result is then passed to the
511 output routine and generates either diff-raw format (see Output
513 diff-patch format.</p></div>
514 </div>
515 <h2 id="_diffcore_break_for_splitting_up_complete_rewrites">diffcore-break: For Splitting Up "Complete Rewrites"</h2>
519 used to detect a filepair that represents "complete rewrite" and
520 break such filepair into two filepairs that represent delete and
521 create. E.g. If the input contained this filepair:</p></div>
525 </div></div>
527 it changes it to:</p></div>
532 </div></div>
534 the extent of changes between the contents of the files before
535 and after modification (i.e. the contents that have "bcd1234…"
536 and "0123456…" as their SHA1 content ID, in the above
537 example). The amount of deletion of original contents and
538 insertion of new material are added together, and if it exceeds
539 the "break score", the filepair is broken into two. The break
540 score defaults to 50% of the size of the smaller of the original
541 and the result (i.e. if the edit shrinks the file, the size of
542 the result is used; if the edit lengthens the file, the size of
543 the original is used), and can be customized by giving a number
545 </div>
546 <h2 id="_diffcore_rename_for_detection_renames_and_copies">diffcore-rename: For Detection Renames and Copies</h2>
549 controlled by the -M option (to detect renames) and the -C option
551 input contained these filepairs:</p></div>
556 </div></div>
558 the contents of the created file file0, then rename detection
559 merges these filepairs and creates:</p></div>
563 </div></div>
564 <div class="paragraph"><p>When the "-C" option is used, the original contents of modified files,
565 and deleted files (and also unmodified files, if the
566 "--find-copies-harder" option is used) are considered as candidates
567 of the source files in rename/copy operation. If the input were like
568 these filepairs, that talk about a modified file fileY and a newly
569 created file file0:</p></div>
574 </div></div>
576 file0 are compared, and if they are similar enough, they are
577 changed to:</p></div>
582 </div></div>
584 algorithm used in diffcore-break is used to determine if two
585 files are "similar enough", and can be customized to use
586 a similarity score different from the default of 50% by giving a
591 diffcore mechanism as well as modified ones. This lets the copy
592 detector consider unmodified files as copy source candidates at
595 copied happened to have been modified in the same changeset.</p></div>
596 </div>
597 <h2 id="_diffcore_merge_broken_for_putting_complete_rewrites_back_together">diffcore-merge-broken: For Putting "Complete Rewrites" Back Together</h2>
600 diffcore-break, and not transformed into rename/copy by
601 diffcore-rename, back into a single modification. This always
602 runs when diffcore-break is used.</p></div>
604 different "extent of changes" computation from the ones used by
605 diffcore-break and diffcore-rename. It counts only the deletion
606 from the original, and does not count insertion. If you removed
608 new lines to make a new 1000-line document, you did not do a
609 complete rewrite. diffcore-break breaks such a case in order to
610 help diffcore-rename to consider such filepairs as candidate of
611 rename/copy detection, but if filepairs broken that way were not
612 matched with other filepairs to create rename/copy, then this
613 transformation merges them back into the original
617 material is deleted, the broken pairs are merged back into a
618 single modification) by giving a second number to -B option,
619 like these:</p></div>
621 <li>
622 <p>
624 for diffcore-merge-broken).
625 </p>
626 </li>
627 <li>
628 <p>
630 </p>
631 </li>
632 </ul></div>
634 creation and deletion patches. This was an unnecessary hack and
635 the latest implementation always merges all the broken pairs
636 back into modifications, but the resulting patch output is
637 formatted differently for easier review in case of such
638 a complete rewrite by showing the entire contents of old version
641 </div>
642 <h2 id="_diffcore_pickaxe_for_detecting_addition_deletion_of_specified_string">diffcore-pickaxe: For Detecting Addition/Deletion of Specified String</h2>
645 changes that touch a specified string, and is controlled by the
647 commands.</p></div>
650 different number of specified string. Such a filepair represents
651 "the string appeared in this changeset". It also checks for the
652 opposite case that loses the specified string.</p></div>
654 only such filepairs that touch the specified string in its
656 filepairs intact if there is such a filepair, or makes the
657 output empty otherwise. The latter behaviour is designed to
658 make reviewing of the changes in the context of the whole
659 changeset easier.</p></div>
660 </div>
661 <h2 id="_diffcore_order_for_sorting_the_output_based_on_filenames">diffcore-order: For Sorting the Output Based on Filenames</h2>
664 (or project’s) taste, and is controlled by the -O option to the
667 pattern. Filepairs that match a glob pattern on an earlier line
668 in the file are output before ones that match a later line, and
669 filepairs that do not match any glob pattern are output last.</p></div>
671 would look like this:</p></div>
674 <pre><tt>README
675 Makefile
676 Documentation
677 *.h
678 *.c
679 t</tt></pre>
680 </div></div>
681 </div>
692 </div>
696 </div>
700 </div>
701 </div>
702 </body>
703 </html>