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1 '\" t
2 .\" Title: gittutorial
3 .\" Author: [FIXME: author] [see http://www.docbook.org/tdg5/en/html/author]
4 .\" Generator: DocBook XSL Stylesheets vsnapshot <http://docbook.sf.net/>
5 .\" Date: 2023-08-14
6 .\" Manual: Git Manual
7 .\" Source: Git 2.42.0.rc1.11.gfc6bba66bc
8 .\" Language: English
9 .\"
10 .TH "GITTUTORIAL" "7" "2023\-08\-14" "Git 2\&.42\&.0\&.rc1\&.11\&.gf" "Git Manual"
11 .\" -----------------------------------------------------------------
12 .\" * Define some portability stuff
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14 .\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
15 .\" http://bugs.debian.org/507673
16 .\" http://lists.gnu.org/archive/html/groff/2009-02/msg00013.html
17 .\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
18 .ie \n(.g .ds Aq \(aq
19 .el .ds Aq '
20 .\" -----------------------------------------------------------------
21 .\" * set default formatting
22 .\" -----------------------------------------------------------------
23 .\" disable hyphenation
24 .nh
25 .\" disable justification (adjust text to left margin only)
26 .ad l
27 .\" -----------------------------------------------------------------
28 .\" * MAIN CONTENT STARTS HERE *
29 .\" -----------------------------------------------------------------
30 .SH "NAME"
31 gittutorial \- A tutorial introduction to Git
32 .SH "SYNOPSIS"
33 .sp
34 .nf
35 git *
36 .fi
37 .sp
38 .SH "DESCRIPTION"
39 .sp
40 This tutorial explains how to import a new project into Git, make changes to it, and share changes with other developers\&.
41 .sp
42 If you are instead primarily interested in using Git to fetch a project, for example, to test the latest version, you may prefer to start with the first two chapters of \m[blue]\fBThe Git User\(cqs Manual\fR\m[]\&\s-2\u[1]\d\s+2\&.
43 .sp
44 First, note that you can get documentation for a command such as \fBgit log \-\-graph\fR with:
45 .sp
46 .if n \{\
47 .RS 4
48 .\}
49 .nf
50 $ man git\-log
51 .fi
52 .if n \{\
53 .RE
54 .\}
55 .sp
56 .sp
57 or:
58 .sp
59 .if n \{\
60 .RS 4
61 .\}
62 .nf
63 $ git help log
64 .fi
65 .if n \{\
66 .RE
67 .\}
68 .sp
69 .sp
70 With the latter, you can use the manual viewer of your choice; see \fBgit-help\fR(1) for more information\&.
71 .sp
72 It is a good idea to introduce yourself to Git with your name and public email address before doing any operation\&. The easiest way to do so is:
73 .sp
74 .if n \{\
75 .RS 4
76 .\}
77 .nf
78 $ git config \-\-global user\&.name "Your Name Comes Here"
79 $ git config \-\-global user\&.email you@yourdomain\&.example\&.com
80 .fi
81 .if n \{\
82 .RE
83 .\}
84 .sp
85 .SH "IMPORTING A NEW PROJECT"
86 .sp
87 Assume you have a tarball \fBproject\&.tar\&.gz\fR with your initial work\&. You can place it under Git revision control as follows\&.
88 .sp
89 .if n \{\
90 .RS 4
91 .\}
92 .nf
93 $ tar xzf project\&.tar\&.gz
94 $ cd project
95 $ git init
96 .fi
97 .if n \{\
98 .RE
99 .\}
100 .sp
101 .sp
102 Git will reply
103 .sp
104 .if n \{\
105 .RS 4
106 .\}
107 .nf
108 Initialized empty Git repository in \&.git/
109 .fi
110 .if n \{\
111 .RE
112 .\}
113 .sp
114 .sp
115 You\(cqve now initialized the working directory\(emyou may notice a new directory created, named \fB\&.git\fR\&.
116 .sp
117 Next, tell Git to take a snapshot of the contents of all files under the current directory (note the \fB\&.\fR), with \fBgit add\fR:
118 .sp
119 .if n \{\
120 .RS 4
121 .\}
122 .nf
123 $ git add \&.
124 .fi
125 .if n \{\
126 .RE
127 .\}
128 .sp
129 .sp
130 This snapshot is now stored in a temporary staging area which Git calls the "index"\&. You can permanently store the contents of the index in the repository with \fBgit commit\fR:
131 .sp
132 .if n \{\
133 .RS 4
134 .\}
135 .nf
136 $ git commit
137 .fi
138 .if n \{\
139 .RE
140 .\}
141 .sp
142 .sp
143 This will prompt you for a commit message\&. You\(cqve now stored the first version of your project in Git\&.
144 .SH "MAKING CHANGES"
145 .sp
146 Modify some files, then add their updated contents to the index:
147 .sp
148 .if n \{\
149 .RS 4
150 .\}
151 .nf
152 $ git add file1 file2 file3
153 .fi
154 .if n \{\
155 .RE
156 .\}
157 .sp
158 .sp
159 You are now ready to commit\&. You can see what is about to be committed using \fBgit diff\fR with the \fB\-\-cached\fR option:
160 .sp
161 .if n \{\
162 .RS 4
163 .\}
164 .nf
165 $ git diff \-\-cached
166 .fi
167 .if n \{\
168 .RE
169 .\}
170 .sp
171 .sp
172 (Without \fB\-\-cached\fR, \fBgit diff\fR will show you any changes that you\(cqve made but not yet added to the index\&.) You can also get a brief summary of the situation with \fBgit status\fR:
173 .sp
174 .if n \{\
175 .RS 4
176 .\}
177 .nf
178 $ git status
179 On branch master
180 Changes to be committed:
181 (use "git restore \-\-staged <file>\&.\&.\&." to unstage)
183 modified: file1
184 modified: file2
185 modified: file3
186 .fi
187 .if n \{\
188 .RE
189 .\}
190 .sp
191 .sp
192 If you need to make any further adjustments, do so now, and then add any newly modified content to the index\&. Finally, commit your changes with:
193 .sp
194 .if n \{\
195 .RS 4
196 .\}
197 .nf
198 $ git commit
199 .fi
200 .if n \{\
201 .RE
202 .\}
203 .sp
204 .sp
205 This will again prompt you for a message describing the change, and then record a new version of the project\&.
206 .sp
207 Alternatively, instead of running \fBgit add\fR beforehand, you can use
208 .sp
209 .if n \{\
210 .RS 4
211 .\}
212 .nf
213 $ git commit \-a
214 .fi
215 .if n \{\
216 .RE
217 .\}
218 .sp
219 .sp
220 which will automatically notice any modified (but not new) files, add them to the index, and commit, all in one step\&.
221 .sp
222 A note on commit messages: Though not required, it\(cqs a good idea to begin the commit message with a single short (less than 50 character) line summarizing the change, followed by a blank line and then a more thorough description\&. The text up to the first blank line in a commit message is treated as the commit title, and that title is used throughout Git\&. For example, \fBgit-format-patch\fR(1) turns a commit into email, and it uses the title on the Subject line and the rest of the commit in the body\&.
223 .SH "GIT TRACKS CONTENT NOT FILES"
224 .sp
225 Many revision control systems provide an \fBadd\fR command that tells the system to start tracking changes to a new file\&. Git\(cqs \fBadd\fR command does something simpler and more powerful: \fBgit add\fR is used both for new and newly modified files, and in both cases it takes a snapshot of the given files and stages that content in the index, ready for inclusion in the next commit\&.
226 .SH "VIEWING PROJECT HISTORY"
227 .sp
228 At any point you can view the history of your changes using
229 .sp
230 .if n \{\
231 .RS 4
232 .\}
233 .nf
234 $ git log
235 .fi
236 .if n \{\
237 .RE
238 .\}
239 .sp
240 .sp
241 If you also want to see complete diffs at each step, use
242 .sp
243 .if n \{\
244 .RS 4
245 .\}
246 .nf
247 $ git log \-p
248 .fi
249 .if n \{\
250 .RE
251 .\}
252 .sp
253 .sp
254 Often the overview of the change is useful to get a feel of each step
255 .sp
256 .if n \{\
257 .RS 4
258 .\}
259 .nf
260 $ git log \-\-stat \-\-summary
261 .fi
262 .if n \{\
263 .RE
264 .\}
265 .sp
266 .SH "MANAGING BRANCHES"
267 .sp
268 A single Git repository can maintain multiple branches of development\&. To create a new branch named \fBexperimental\fR, use
269 .sp
270 .if n \{\
271 .RS 4
272 .\}
273 .nf
274 $ git branch experimental
275 .fi
276 .if n \{\
277 .RE
278 .\}
279 .sp
280 .sp
281 If you now run
282 .sp
283 .if n \{\
284 .RS 4
285 .\}
286 .nf
287 $ git branch
288 .fi
289 .if n \{\
290 .RE
291 .\}
292 .sp
293 .sp
294 you\(cqll get a list of all existing branches:
295 .sp
296 .if n \{\
297 .RS 4
298 .\}
299 .nf
300 experimental
301 * master
302 .fi
303 .if n \{\
304 .RE
305 .\}
306 .sp
307 .sp
308 The \fBexperimental\fR branch is the one you just created, and the \fBmaster\fR branch is a default branch that was created for you automatically\&. The asterisk marks the branch you are currently on; type
309 .sp
310 .if n \{\
311 .RS 4
312 .\}
313 .nf
314 $ git switch experimental
315 .fi
316 .if n \{\
317 .RE
318 .\}
319 .sp
320 .sp
321 to switch to the \fBexperimental\fR branch\&. Now edit a file, commit the change, and switch back to the \fBmaster\fR branch:
322 .sp
323 .if n \{\
324 .RS 4
325 .\}
326 .nf
327 (edit file)
328 $ git commit \-a
329 $ git switch master
330 .fi
331 .if n \{\
332 .RE
333 .\}
334 .sp
335 .sp
336 Check that the change you made is no longer visible, since it was made on the \fBexperimental\fR branch and you\(cqre back on the \fBmaster\fR branch\&.
337 .sp
338 You can make a different change on the \fBmaster\fR branch:
339 .sp
340 .if n \{\
341 .RS 4
342 .\}
343 .nf
344 (edit file)
345 $ git commit \-a
346 .fi
347 .if n \{\
348 .RE
349 .\}
350 .sp
351 .sp
352 at this point the two branches have diverged, with different changes made in each\&. To merge the changes made in \fBexperimental\fR into \fBmaster\fR, run
353 .sp
354 .if n \{\
355 .RS 4
356 .\}
357 .nf
358 $ git merge experimental
359 .fi
360 .if n \{\
361 .RE
362 .\}
363 .sp
364 .sp
365 If the changes don\(cqt conflict, you\(cqre done\&. If there are conflicts, markers will be left in the problematic files showing the conflict;
366 .sp
367 .if n \{\
368 .RS 4
369 .\}
370 .nf
371 $ git diff
372 .fi
373 .if n \{\
374 .RE
375 .\}
376 .sp
377 .sp
378 will show this\&. Once you\(cqve edited the files to resolve the conflicts,
379 .sp
380 .if n \{\
381 .RS 4
382 .\}
383 .nf
384 $ git commit \-a
385 .fi
386 .if n \{\
387 .RE
388 .\}
389 .sp
390 .sp
391 will commit the result of the merge\&. Finally,
392 .sp
393 .if n \{\
394 .RS 4
395 .\}
396 .nf
397 $ gitk
398 .fi
399 .if n \{\
400 .RE
401 .\}
402 .sp
403 .sp
404 will show a nice graphical representation of the resulting history\&.
405 .sp
406 At this point you could delete the \fBexperimental\fR branch with
407 .sp
408 .if n \{\
409 .RS 4
410 .\}
411 .nf
412 $ git branch \-d experimental
413 .fi
414 .if n \{\
415 .RE
416 .\}
417 .sp
418 .sp
419 This command ensures that the changes in the \fBexperimental\fR branch are already in the current branch\&.
420 .sp
421 If you develop on a branch \fBcrazy\-idea\fR, then regret it, you can always delete the branch with
422 .sp
423 .if n \{\
424 .RS 4
425 .\}
426 .nf
427 $ git branch \-D crazy\-idea
428 .fi
429 .if n \{\
430 .RE
431 .\}
432 .sp
433 .sp
434 Branches are cheap and easy, so this is a good way to try something out\&.
435 .SH "USING GIT FOR COLLABORATION"
436 .sp
437 Suppose that Alice has started a new project with a Git repository in \fB/home/alice/project\fR, and that Bob, who has a home directory on the same machine, wants to contribute\&.
438 .sp
439 Bob begins with:
440 .sp
441 .if n \{\
442 .RS 4
443 .\}
444 .nf
445 bob$ git clone /home/alice/project myrepo
446 .fi
447 .if n \{\
448 .RE
449 .\}
450 .sp
451 .sp
452 This creates a new directory \fBmyrepo\fR containing a clone of Alice\(cqs repository\&. The clone is on an equal footing with the original project, possessing its own copy of the original project\(cqs history\&.
453 .sp
454 Bob then makes some changes and commits them:
455 .sp
456 .if n \{\
457 .RS 4
458 .\}
459 .nf
460 (edit files)
461 bob$ git commit \-a
462 (repeat as necessary)
463 .fi
464 .if n \{\
465 .RE
466 .\}
467 .sp
468 .sp
469 When he\(cqs ready, he tells Alice to pull changes from the repository at \fB/home/bob/myrepo\fR\&. She does this with:
470 .sp
471 .if n \{\
472 .RS 4
473 .\}
474 .nf
475 alice$ cd /home/alice/project
476 alice$ git pull /home/bob/myrepo master
477 .fi
478 .if n \{\
479 .RE
480 .\}
481 .sp
482 .sp
483 This merges the changes from Bob\(cqs \fBmaster\fR branch into Alice\(cqs current branch\&. If Alice has made her own changes in the meantime, then she may need to manually fix any conflicts\&.
484 .sp
485 The \fBpull\fR command thus performs two operations: it fetches changes from a remote branch, then merges them into the current branch\&.
486 .sp
487 Note that in general, Alice would want her local changes committed before initiating this \fBpull\fR\&. If Bob\(cqs work conflicts with what Alice did since their histories forked, Alice will use her working tree and the index to resolve conflicts, and existing local changes will interfere with the conflict resolution process (Git will still perform the fetch but will refuse to merge \(em Alice will have to get rid of her local changes in some way and pull again when this happens)\&.
488 .sp
489 Alice can peek at what Bob did without merging first, using the \fBfetch\fR command; this allows Alice to inspect what Bob did, using a special symbol \fBFETCH_HEAD\fR, in order to determine if he has anything worth pulling, like this:
490 .sp
491 .if n \{\
492 .RS 4
493 .\}
494 .nf
495 alice$ git fetch /home/bob/myrepo master
496 alice$ git log \-p HEAD\&.\&.FETCH_HEAD
497 .fi
498 .if n \{\
499 .RE
500 .\}
501 .sp
502 .sp
503 This operation is safe even if Alice has uncommitted local changes\&. The range notation \fBHEAD\&.\&.FETCH_HEAD\fR means "show everything that is reachable from the \fBFETCH_HEAD\fR but exclude anything that is reachable from \fBHEAD\fR"\&. Alice already knows everything that leads to her current state (\fBHEAD\fR), and reviews what Bob has in his state (\fBFETCH_HEAD\fR) that she has not seen with this command\&.
504 .sp
505 If Alice wants to visualize what Bob did since their histories forked she can issue the following command:
506 .sp
507 .if n \{\
508 .RS 4
509 .\}
510 .nf
511 $ gitk HEAD\&.\&.FETCH_HEAD
512 .fi
513 .if n \{\
514 .RE
515 .\}
516 .sp
517 .sp
518 This uses the same two\-dot range notation we saw earlier with \fBgit log\fR\&.
519 .sp
520 Alice may want to view what both of them did since they forked\&. She can use three\-dot form instead of the two\-dot form:
521 .sp
522 .if n \{\
523 .RS 4
524 .\}
525 .nf
526 $ gitk HEAD\&.\&.\&.FETCH_HEAD
527 .fi
528 .if n \{\
529 .RE
530 .\}
531 .sp
532 .sp
533 This means "show everything that is reachable from either one, but exclude anything that is reachable from both of them"\&.
534 .sp
535 Please note that these range notation can be used with both \fBgitk\fR and \fBgit log\fR\&.
536 .sp
537 After inspecting what Bob did, if there is nothing urgent, Alice may decide to continue working without pulling from Bob\&. If Bob\(cqs history does have something Alice would immediately need, Alice may choose to stash her work\-in\-progress first, do a \fBpull\fR, and then finally unstash her work\-in\-progress on top of the resulting history\&.
538 .sp
539 When you are working in a small closely knit group, it is not unusual to interact with the same repository over and over again\&. By defining \fIremote\fR repository shorthand, you can make it easier:
540 .sp
541 .if n \{\
542 .RS 4
543 .\}
544 .nf
545 alice$ git remote add bob /home/bob/myrepo
546 .fi
547 .if n \{\
548 .RE
549 .\}
550 .sp
551 .sp
552 With this, Alice can perform the first part of the \fBpull\fR operation alone using the \fBgit fetch\fR command without merging them with her own branch, using:
553 .sp
554 .if n \{\
555 .RS 4
556 .\}
557 .nf
558 alice$ git fetch bob
559 .fi
560 .if n \{\
561 .RE
562 .\}
563 .sp
564 .sp
565 Unlike the longhand form, when Alice fetches from Bob using a remote repository shorthand set up with \fBgit remote\fR, what was fetched is stored in a remote\-tracking branch, in this case \fBbob/master\fR\&. So after this:
566 .sp
567 .if n \{\
568 .RS 4
569 .\}
570 .nf
571 alice$ git log \-p master\&.\&.bob/master
572 .fi
573 .if n \{\
574 .RE
575 .\}
576 .sp
577 .sp
578 shows a list of all the changes that Bob made since he branched from Alice\(cqs \fBmaster\fR branch\&.
579 .sp
580 After examining those changes, Alice could merge the changes into her \fBmaster\fR branch:
581 .sp
582 .if n \{\
583 .RS 4
584 .\}
585 .nf
586 alice$ git merge bob/master
587 .fi
588 .if n \{\
589 .RE
590 .\}
591 .sp
592 .sp
593 This \fBmerge\fR can also be done by \fIpulling from her own remote\-tracking branch\fR, like this:
594 .sp
595 .if n \{\
596 .RS 4
597 .\}
598 .nf
599 alice$ git pull \&. remotes/bob/master
600 .fi
601 .if n \{\
602 .RE
603 .\}
604 .sp
605 .sp
606 Note that git pull always merges into the current branch, regardless of what else is given on the command line\&.
607 .sp
608 Later, Bob can update his repo with Alice\(cqs latest changes using
609 .sp
610 .if n \{\
611 .RS 4
612 .\}
613 .nf
614 bob$ git pull
615 .fi
616 .if n \{\
617 .RE
618 .\}
619 .sp
620 .sp
621 Note that he doesn\(cqt need to give the path to Alice\(cqs repository; when Bob cloned Alice\(cqs repository, Git stored the location of her repository in the repository configuration, and that location is used for pulls:
622 .sp
623 .if n \{\
624 .RS 4
625 .\}
626 .nf
627 bob$ git config \-\-get remote\&.origin\&.url
628 /home/alice/project
629 .fi
630 .if n \{\
631 .RE
632 .\}
633 .sp
634 .sp
635 (The complete configuration created by \fBgit clone\fR is visible using \fBgit config \-l\fR, and the \fBgit-config\fR(1) man page explains the meaning of each option\&.)
636 .sp
637 Git also keeps a pristine copy of Alice\(cqs \fBmaster\fR branch under the name \fBorigin/master\fR:
638 .sp
639 .if n \{\
640 .RS 4
641 .\}
642 .nf
643 bob$ git branch \-r
644 origin/master
645 .fi
646 .if n \{\
647 .RE
648 .\}
649 .sp
650 .sp
651 If Bob later decides to work from a different host, he can still perform clones and pulls using the ssh protocol:
652 .sp
653 .if n \{\
654 .RS 4
655 .\}
656 .nf
657 bob$ git clone alice\&.org:/home/alice/project myrepo
658 .fi
659 .if n \{\
660 .RE
661 .\}
662 .sp
663 .sp
664 Alternatively, Git has a native protocol, or can use http; see \fBgit-pull\fR(1) for details\&.
665 .sp
666 Git can also be used in a CVS\-like mode, with a central repository that various users push changes to; see \fBgit-push\fR(1) and \fBgitcvs-migration\fR(7)\&.
667 .SH "EXPLORING HISTORY"
668 .sp
669 Git history is represented as a series of interrelated commits\&. We have already seen that the \fBgit log\fR command can list those commits\&. Note that first line of each \fBgit log\fR entry also gives a name for the commit:
670 .sp
671 .if n \{\
672 .RS 4
673 .\}
674 .nf
675 $ git log
676 commit c82a22c39cbc32576f64f5c6b3f24b99ea8149c7
677 Author: Junio C Hamano <junkio@cox\&.net>
678 Date: Tue May 16 17:18:22 2006 \-0700
680 merge\-base: Clarify the comments on post processing\&.
681 .fi
682 .if n \{\
683 .RE
684 .\}
685 .sp
686 .sp
687 We can give this name to \fBgit show\fR to see the details about this commit\&.
688 .sp
689 .if n \{\
690 .RS 4
691 .\}
692 .nf
693 $ git show c82a22c39cbc32576f64f5c6b3f24b99ea8149c7
694 .fi
695 .if n \{\
696 .RE
697 .\}
698 .sp
699 .sp
700 But there are other ways to refer to commits\&. You can use any initial part of the name that is long enough to uniquely identify the commit:
701 .sp
702 .if n \{\
703 .RS 4
704 .\}
705 .nf
706 $ git show c82a22c39c # the first few characters of the name are
707 # usually enough
708 $ git show HEAD # the tip of the current branch
709 $ git show experimental # the tip of the "experimental" branch
710 .fi
711 .if n \{\
712 .RE
713 .\}
714 .sp
715 .sp
716 Every commit usually has one "parent" commit which points to the previous state of the project:
717 .sp
718 .if n \{\
719 .RS 4
720 .\}
721 .nf
722 $ git show HEAD^ # to see the parent of HEAD
723 $ git show HEAD^^ # to see the grandparent of HEAD
724 $ git show HEAD~4 # to see the great\-great grandparent of HEAD
725 .fi
726 .if n \{\
727 .RE
728 .\}
729 .sp
730 .sp
731 Note that merge commits may have more than one parent:
732 .sp
733 .if n \{\
734 .RS 4
735 .\}
736 .nf
737 $ git show HEAD^1 # show the first parent of HEAD (same as HEAD^)
738 $ git show HEAD^2 # show the second parent of HEAD
739 .fi
740 .if n \{\
741 .RE
742 .\}
743 .sp
744 .sp
745 You can also give commits names of your own; after running
746 .sp
747 .if n \{\
748 .RS 4
749 .\}
750 .nf
751 $ git tag v2\&.5 1b2e1d63ff
752 .fi
753 .if n \{\
754 .RE
755 .\}
756 .sp
757 .sp
758 you can refer to \fB1b2e1d63ff\fR by the name \fBv2\&.5\fR\&. If you intend to share this name with other people (for example, to identify a release version), you should create a "tag" object, and perhaps sign it; see \fBgit-tag\fR(1) for details\&.
759 .sp
760 Any Git command that needs to know a commit can take any of these names\&. For example:
761 .sp
762 .if n \{\
763 .RS 4
764 .\}
765 .nf
766 $ git diff v2\&.5 HEAD # compare the current HEAD to v2\&.5
767 $ git branch stable v2\&.5 # start a new branch named "stable" based
768 # at v2\&.5
769 $ git reset \-\-hard HEAD^ # reset your current branch and working
770 # directory to its state at HEAD^
771 .fi
772 .if n \{\
773 .RE
774 .\}
775 .sp
776 .sp
777 Be careful with that last command: in addition to losing any changes in the working directory, it will also remove all later commits from this branch\&. If this branch is the only branch containing those commits, they will be lost\&. Also, don\(cqt use \fBgit reset\fR on a publicly\-visible branch that other developers pull from, as it will force needless merges on other developers to clean up the history\&. If you need to undo changes that you have pushed, use \fBgit revert\fR instead\&.
778 .sp
779 The \fBgit grep\fR command can search for strings in any version of your project, so
780 .sp
781 .if n \{\
782 .RS 4
783 .\}
784 .nf
785 $ git grep "hello" v2\&.5
786 .fi
787 .if n \{\
788 .RE
789 .\}
790 .sp
791 .sp
792 searches for all occurrences of "hello" in \fBv2\&.5\fR\&.
793 .sp
794 If you leave out the commit name, \fBgit grep\fR will search any of the files it manages in your current directory\&. So
795 .sp
796 .if n \{\
797 .RS 4
798 .\}
799 .nf
800 $ git grep "hello"
801 .fi
802 .if n \{\
803 .RE
804 .\}
805 .sp
806 .sp
807 is a quick way to search just the files that are tracked by Git\&.
808 .sp
809 Many Git commands also take sets of commits, which can be specified in a number of ways\&. Here are some examples with \fBgit log\fR:
810 .sp
811 .if n \{\
812 .RS 4
813 .\}
814 .nf
815 $ git log v2\&.5\&.\&.v2\&.6 # commits between v2\&.5 and v2\&.6
816 $ git log v2\&.5\&.\&. # commits since v2\&.5
817 $ git log \-\-since="2 weeks ago" # commits from the last 2 weeks
818 $ git log v2\&.5\&.\&. Makefile # commits since v2\&.5 which modify
819 # Makefile
820 .fi
821 .if n \{\
822 .RE
823 .\}
824 .sp
825 .sp
826 You can also give \fBgit log\fR a "range" of commits where the first is not necessarily an ancestor of the second; for example, if the tips of the branches \fBstable\fR and \fBmaster\fR diverged from a common commit some time ago, then
827 .sp
828 .if n \{\
829 .RS 4
830 .\}
831 .nf
832 $ git log stable\&.\&.master
833 .fi
834 .if n \{\
835 .RE
836 .\}
837 .sp
838 .sp
839 will list commits made in the \fBmaster\fR branch but not in the stable branch, while
840 .sp
841 .if n \{\
842 .RS 4
843 .\}
844 .nf
845 $ git log master\&.\&.stable
846 .fi
847 .if n \{\
848 .RE
849 .\}
850 .sp
851 .sp
852 will show the list of commits made on the stable branch but not the \fBmaster\fR branch\&.
853 .sp
854 The \fBgit log\fR command has a weakness: it must present commits in a list\&. When the history has lines of development that diverged and then merged back together, the order in which \fBgit log\fR presents those commits is meaningless\&.
855 .sp
856 Most projects with multiple contributors (such as the Linux kernel, or Git itself) have frequent merges, and \fBgitk\fR does a better job of visualizing their history\&. For example,
857 .sp
858 .if n \{\
859 .RS 4
860 .\}
861 .nf
862 $ gitk \-\-since="2 weeks ago" drivers/
863 .fi
864 .if n \{\
865 .RE
866 .\}
867 .sp
868 .sp
869 allows you to browse any commits from the last 2 weeks of commits that modified files under the \fBdrivers\fR directory\&. (Note: you can adjust gitk\(cqs fonts by holding down the control key while pressing "\-" or "+"\&.)
870 .sp
871 Finally, most commands that take filenames will optionally allow you to precede any filename by a commit, to specify a particular version of the file:
872 .sp
873 .if n \{\
874 .RS 4
875 .\}
876 .nf
877 $ git diff v2\&.5:Makefile HEAD:Makefile\&.in
878 .fi
879 .if n \{\
880 .RE
881 .\}
882 .sp
883 .sp
884 You can also use \fBgit show\fR to see any such file:
885 .sp
886 .if n \{\
887 .RS 4
888 .\}
889 .nf
890 $ git show v2\&.5:Makefile
891 .fi
892 .if n \{\
893 .RE
894 .\}
895 .sp
896 .SH "NEXT STEPS"
897 .sp
898 This tutorial should be enough to perform basic distributed revision control for your projects\&. However, to fully understand the depth and power of Git you need to understand two simple ideas on which it is based:
899 .sp
900 .RS 4
901 .ie n \{\
902 \h'-04'\(bu\h'+03'\c
903 .\}
904 .el \{\
905 .sp -1
906 .IP \(bu 2.3
907 .\}
908 The object database is the rather elegant system used to store the history of your project\(emfiles, directories, and commits\&.
909 .RE
910 .sp
911 .RS 4
912 .ie n \{\
913 \h'-04'\(bu\h'+03'\c
914 .\}
915 .el \{\
916 .sp -1
917 .IP \(bu 2.3
918 .\}
919 The index file is a cache of the state of a directory tree, used to create commits, check out working directories, and hold the various trees involved in a merge\&.
920 .RE
921 .sp
922 Part two of this tutorial explains the object database, the index file, and a few other odds and ends that you\(cqll need to make the most of Git\&. You can find it at \fBgittutorial-2\fR(7)\&.
923 .sp
924 If you don\(cqt want to continue with that right away, a few other digressions that may be interesting at this point are:
925 .sp
926 .RS 4
927 .ie n \{\
928 \h'-04'\(bu\h'+03'\c
929 .\}
930 .el \{\
931 .sp -1
932 .IP \(bu 2.3
933 .\}
934 \fBgit-format-patch\fR(1),
935 \fBgit-am\fR(1): These convert series of git commits into emailed patches, and vice versa, useful for projects such as the Linux kernel which rely heavily on emailed patches\&.
936 .RE
937 .sp
938 .RS 4
939 .ie n \{\
940 \h'-04'\(bu\h'+03'\c
941 .\}
942 .el \{\
943 .sp -1
944 .IP \(bu 2.3
945 .\}
946 \fBgit-bisect\fR(1): When there is a regression in your project, one way to track down the bug is by searching through the history to find the exact commit that\(cqs to blame\&.
947 \fBgit bisect\fR
948 can help you perform a binary search for that commit\&. It is smart enough to perform a close\-to\-optimal search even in the case of complex non\-linear history with lots of merged branches\&.
949 .RE
950 .sp
951 .RS 4
952 .ie n \{\
953 \h'-04'\(bu\h'+03'\c
954 .\}
955 .el \{\
956 .sp -1
957 .IP \(bu 2.3
958 .\}
959 \fBgitworkflows\fR(7): Gives an overview of recommended workflows\&.
960 .RE
961 .sp
962 .RS 4
963 .ie n \{\
964 \h'-04'\(bu\h'+03'\c
965 .\}
966 .el \{\
967 .sp -1
968 .IP \(bu 2.3
969 .\}
970 \fBgiteveryday\fR(7): Everyday Git with 20 Commands Or So\&.
971 .RE
972 .sp
973 .RS 4
974 .ie n \{\
975 \h'-04'\(bu\h'+03'\c
976 .\}
977 .el \{\
978 .sp -1
979 .IP \(bu 2.3
980 .\}
981 \fBgitcvs-migration\fR(7): Git for CVS users\&.
982 .RE
983 .SH "SEE ALSO"
984 .sp
985 \fBgittutorial-2\fR(7), \fBgitcvs-migration\fR(7), \fBgitcore-tutorial\fR(7), \fBgitglossary\fR(7), \fBgit-help\fR(1), \fBgitworkflows\fR(7), \fBgiteveryday\fR(7), \m[blue]\fBThe Git User\(cqs Manual\fR\m[]\&\s-2\u[1]\d\s+2
986 .SH "GIT"
987 .sp
988 Part of the \fBgit\fR(1) suite
989 .SH "NOTES"
990 .IP " 1." 4
991 The Git User\(cqs Manual
992 .RS 4
993 \%git-htmldocs/user-manual.html
994 .RE