| blob | 966aaa6b312b33a9558ac9f952aa14d2a9f1fd6c |
4 <head>
8 /* Debug borders */
10 /*
11 border: 1px solid red;
12 */
13 }
15 body {
17 }
19 a {
22 }
25 }
27 em {
29 }
31 strong {
33 }
35 tt {
37 }
45 }
49 }
50 h2 {
52 }
53 h3 {
55 }
56 h3 + * {
58 }
63 }
65 hr {
67 }
69 p {
72 }
74 pre {
77 }
79 span#author {
84 }
85 span#email {
86 }
87 span#revision {
89 }
91 div#footer {
97 }
98 div#footer-text {
101 }
102 div#footer-badges {
105 }
107 div#preamble,
114 }
118 }
122 }
124 /* Block element titles. */
131 }
134 }
138 }
141 }
144 }
150 }
154 }
159 }
163 }
167 }
170 }
179 }
183 }
188 }
192 }
198 dl {
201 }
202 dt {
206 }
209 }
213 }
216 }
220 }
221 thead {
224 }
225 tfoot {
227 }
232 }
235 }
240 }
243 }
247 }
249 div#toctitle {
256 }
261 }
265 }
269 }
273 }
275 /* Workarounds for IE6's broken and incomplete CSS2. */
281 }
287 }
293 }
297 }
302 }
304 /* IE6 sets dynamically generated links as visited. */
306 </style>
308 </head>
309 <body>
311 <h1>
312 gitdiffcore(7) Manual Page
313 </h1>
316 <p>gitdiffcore -
317 Tweaking diff output (June 2005)
318 </p>
319 </div>
320 </div>
324 </div>
327 <div class="para"><p>The diff commands <em>git-diff-index</em>, <em>git-diff-files</em>, and <em>git-diff-tree</em>
328 can be told to manipulate differences they find in
330 is collectively called "diffcore transformation". This short note
332 that is easier to understand than the conventional kind.</p></div>
333 </div>
337 files:</p></div>
339 <li>
340 <p>
344 used);
345 </p>
346 </li>
347 <li>
348 <p>
350 working directory;
351 </p>
352 </li>
353 <li>
354 <p>
356 </p>
357 </li>
358 </ul></div>
360 the two sets of files by any pathspecs given on their command-lines,
361 and compare corresponding paths in the two resulting sets of files.</p></div>
363 the filepairs outside the specified sets of pathnames. E.g. If the
364 input set of filepairs included:</p></div>
368 </div></div>
370 junkfile entry would be removed from the list because only "myfile"
371 is under consideration.</p></div>
373 internally called "diffcore", in a format similar to what is output
374 when the -p option is not used. E.g.</p></div>
381 </div></div>
383 (each of which is called "filepair", although at this point each
384 of them talks about a single file), and transforms such a list
387 <li>
388 <p>
389 diffcore-break
390 </p>
391 </li>
392 <li>
393 <p>
394 diffcore-rename
395 </p>
396 </li>
397 <li>
398 <p>
399 diffcore-merge-broken
400 </p>
401 </li>
402 <li>
403 <p>
404 diffcore-pickaxe
405 </p>
406 </li>
407 <li>
408 <p>
409 diffcore-order
410 </p>
411 </li>
412 </ul></div>
413 <div class="para"><p>These are applied in sequence. The set of filepairs <em>git-diff-*</em>
414 commands find are used as the input to diffcore-break, and
415 the output from diffcore-break is used as the input to the
416 next transformation. The final result is then passed to the
417 output routine and generates either diff-raw format (see Output
419 diff-patch format.</p></div>
420 </div>
421 <h2 id="_diffcore_break_for_splitting_up_complete_rewrites">diffcore-break: For Splitting Up "Complete Rewrites"</h2>
425 used to detect a filepair that represents "complete rewrite" and
426 break such filepair into two filepairs that represent delete and
427 create. E.g. If the input contained this filepair:</p></div>
431 </div></div>
433 it changes it to:</p></div>
438 </div></div>
440 the extent of changes between the contents of the files before
441 and after modification (i.e. the contents that have "bcd1234…"
442 and "0123456…" as their SHA1 content ID, in the above
443 example). The amount of deletion of original contents and
444 insertion of new material are added together, and if it exceeds
445 the "break score", the filepair is broken into two. The break
446 score defaults to 50% of the size of the smaller of the original
447 and the result (i.e. if the edit shrinks the file, the size of
448 the result is used; if the edit lengthens the file, the size of
449 the original is used), and can be customized by giving a number
451 </div>
452 <h2 id="_diffcore_rename_for_detection_renames_and_copies">diffcore-rename: For Detection Renames and Copies</h2>
455 controlled by the -M option (to detect renames) and the -C option
457 input contained these filepairs:</p></div>
462 </div></div>
464 the contents of the created file file0, then rename detection
465 merges these filepairs and creates:</p></div>
469 </div></div>
471 and deleted files (and also unmodified files, if the
472 "--find-copies-harder" option is used) are considered as candidates
473 of the source files in rename/copy operation. If the input were like
474 these filepairs, that talk about a modified file fileY and a newly
475 created file file0:</p></div>
480 </div></div>
482 file0 are compared, and if they are similar enough, they are
483 changed to:</p></div>
488 </div></div>
490 algorithm used in diffcore-break is used to determine if two
491 files are "similar enough", and can be customized to use
492 a similarity score different from the default of 50% by giving a
497 diffcore mechanism as well as modified ones. This lets the copy
498 detector consider unmodified files as copy source candidates at
501 copied happened to have been modified in the same changeset.</p></div>
502 </div>
503 <h2 id="_diffcore_merge_broken_for_putting_complete_rewrites_back_together">diffcore-merge-broken: For Putting "Complete Rewrites" Back Together</h2>
506 diffcore-break, and not transformed into rename/copy by
507 diffcore-rename, back into a single modification. This always
508 runs when diffcore-break is used.</p></div>
510 different "extent of changes" computation from the ones used by
511 diffcore-break and diffcore-rename. It counts only the deletion
512 from the original, and does not count insertion. If you removed
514 new lines to make a new 1000-line document, you did not do a
515 complete rewrite. diffcore-break breaks such a case in order to
516 help diffcore-rename to consider such filepairs as candidate of
517 rename/copy detection, but if filepairs broken that way were not
518 matched with other filepairs to create rename/copy, then this
519 transformation merges them back into the original
523 material is deleted, the broken pairs are merged back into a
524 single modification) by giving a second number to -B option,
525 like these:</p></div>
527 <li>
528 <p>
530 for diffcore-merge-broken).
531 </p>
532 </li>
533 <li>
534 <p>
536 </p>
537 </li>
538 </ul></div>
540 creation and deletion patches. This was an unnecessary hack and
541 the latest implementation always merges all the broken pairs
542 back into modifications, but the resulting patch output is
543 formatted differently for easier review in case of such
544 a complete rewrite by showing the entire contents of old version
547 </div>
548 <h2 id="_diffcore_pickaxe_for_detecting_addition_deletion_of_specified_string">diffcore-pickaxe: For Detecting Addition/Deletion of Specified String</h2>
551 changes that touch a specified string, and is controlled by the
553 commands.</p></div>
555 filepairs whose "original" side has the specified string and
557 string appeared in this changeset". It also checks for the
558 opposite case that loses the specified string.</p></div>
560 only such filepairs that touch the specified string in its
562 filepairs intact if there is such a filepair, or makes the
563 output empty otherwise. The latter behaviour is designed to
564 make reviewing of the changes in the context of the whole
565 changeset easier.</p></div>
566 </div>
567 <h2 id="_diffcore_order_for_sorting_the_output_based_on_filenames">diffcore-order: For Sorting the Output Based on Filenames</h2>
570 (or project's) taste, and is controlled by the -O option to the
573 pattern. Filepairs that match a glob pattern on an earlier line
574 in the file are output before ones that match a later line, and
575 filepairs that do not match any glob pattern are output last.</p></div>
577 would look like this:</p></div>
580 <pre><tt>README
581 Makefile
582 Documentation
583 *.h
584 *.c
585 t</tt></pre>
586 </div></div>
587 </div>
598 </div>
602 </div>
606 </div>
607 </div>
608 </body>
609 </html>