Git Submodule使用完整教程

Git Submodule功能刚刚开始学习可能觉得有点怪异，所以本教程把每一步的操作的命令和结果都用代码的形式展现给大家，以便更好的理解。

1.对于公共资源各种程序员的处理方式

每个公司的系统都会有一套统一的系统风格，或者针对某一个大客户的多个系统风格保持统一，而且如果风格改动后要同步到多个系统中；这样的需求几乎每个开发人员都遇到，下面看看各个层次的程序员怎么处理：

假如对于系统的风格需要几个目录：css、images、js。

• 普通程序员，把最新版本的代码逐个复制到每个项目中，如果有N个项目，那就是要复制N x 3次；如果漏掉了某个文件夹没有复制…@（&#@#。

• 文艺程序员，使用Git Submodule功能，执行：git submodule update，然后冲一杯咖啡悠哉的享受着。

---

引用一段《Git权威指南》的话： 项目的版本库在某些情况虾需要引用其他版本库中的文件，例如公司积累了一套常用的函数库，被多个项目调用，显然这个函数库的代码不能直接放到某个项目的代码中，而是要独立为一个代码库，那么其他项目要调用公共函数库该如何处理呢？分别把公共函数库的文件拷贝到各自的项目中会造成冗余，丢弃了公共函数库的维护历史，这显然不是好的方法。

2.开始学习Git Submodule

“工欲善其事，必先利其器”！

既然文艺程序员那么轻松就搞定了，那我们就把过程一一道来。

说明：本例采用两个项目以及两个公共类库演示对submodule的操作。因为在一写资料或者书上的例子都是一个项目对应1～N个lib，但是实际应用往往并不是这么简单。

2.1 创建Git Submodule测试项目

2.1.1 准备环境

?

1 2 3

➜ henryyan@hy-hp  ~  pwd /home/henryyan mkdir -p submd/repos

创建需要的本地仓库：

?

1 2 3 4 5

cd ~/submd/repos git --git-dir=lib1.git init --bare git --git-dir=lib2.git init --bare git --git-dir=project1.git init --bare git --git-dir=project2.git init --bare

初始化工作区：

?

1 2	mkdir ~/submd/ws cd ~/submd/ws

2.1.2 初始化项目

初始化project1：

?

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007

➜ henryyan@hy-hp  ~/submd/ws  git clone ../repos/project1.git Cloning into project1... done. warning: You appear to have cloned an empty repository.   ➜ henryyan@hy-hp  ~/submd/ws  cd project1 ➜ henryyan@hy-hp  ~/submd/ws/project1 git:(master) echo "project1" > project-infos.txt ➜ henryyan@hy-hp  ~/submd/ws/project1 git:(master) ✗ ls project-infos.txt   ➜ henryyan@hy-hp  ~/submd/ws/project1 git:(master) ✗ git add project-infos.txt ➜ henryyan@hy-hp  ~/submd/ws/project1 git:(master) ✗ git status # On branch master # # Initial commit # # Changes to be committed: #   (use "git rm --cached <file>..." to unstage) # #   new file:   project-infos.txt # ➜ henryyan@hy-hp  ~/submd/ws/project1 git:(master) ✗ git commit -m "init project1" [master (root-commit) 473a2e2] init project1  1 files changed, 1 insertions(+), 0 deletions(-)  create mode 100644 project-infos.txt ➜ henryyan@hy-hp  ~/submd/ws/project1 git:(master) git push origin master Counting objects: 3, done. Writing objects: 100% (3/3), 232 bytes, done. Total 3 (delta 0), reused 0 (delta 0) Unpacking objects: 100% (3/3), done. To /home/henryyan/submd/ws/../repos/project1.git  * [new branch]      master -> master </pre>   初始化project2： <pre class=" shell"> ➜ henryyan@hy-hp  ~/submd/ws/project1 cd .. ➜ henryyan@hy-hp  ~/submd/ws  git clone ../repos/project2.git Cloning into project2... done. warning: You appear to have cloned an empty repository.   ➜ henryyan@hy-hp  ~/submd/ws  cd project2 ➜ henryyan@hy-hp  ~/submd/ws/project2 git:(master) echo "project2" > project-infos.txt ➜ henryyan@hy-hp  ~/submd/ws/project2 git:(master) ✗ ls project-infos.txt   ➜ henryyan@hy-hp  ~/submd/ws/project2 git:(master) ✗ git add project-infos.txt ➜ henryyan@hy-hp  ~/submd/ws/project2 git:(master) ✗ git status # On branch master # # Initial commit # # Changes to be committed: #   (use "git rm --cached <file>..." to unstage) # #   new file:   project-infos.txt # ➜ henryyan@hy-hp  ~/submd/ws/project2 git:(master) ✗ git commit -m "init project2" [master (root-commit) 473a2e2] init project2  1 files changed, 1 insertions(+), 0 deletions(-)  create mode 100644 project-infos.txt ➜ henryyan@hy-hp  ~/submd/ws/project2 git:(master) git push origin master Counting objects: 3, done. Writing objects: 100% (3/3), 232 bytes, done. Total 3 (delta 0), reused 0 (delta 0) Unpacking objects: 100% (3/3), done. To /home/henryyan/submd/ws/../repos/project2.git  * [new branch]      master -> master </pre>   #### 2.1.3 初始化公共类库   初始化公共类库lib1： <pre class=" shell">➜ henryyan@hy-hp  ~/submd/ws  git clone ../repos/lib1.git Cloning into lib1... done. warning: You appear to have cloned an empty repository. ➜ henryyan@hy-hp  ~/submd/ws  cd lib1 ➜ henryyan@hy-hp  ~/submd/ws/lib1 git:(master) echo "I'm lib1." > lib1-features ➜ henryyan@hy-hp  ~/submd/ws/lib1 git:(master) ✗ git add lib1-features ➜ henryyan@hy-hp  ~/submd/ws/lib1 git:(master) ✗ git commit -m "init lib1" [master (root-commit) c22aff8] init lib1  1 files changed, 1 insertions(+), 0 deletions(-)  create mode 100644 lib1-features ➜ henryyan@hy-hp  ~/submd/ws/lib1 git:(master) git push origin master Counting objects: 3, done. Writing objects: 100% (3/3), 227 bytes, done. Total 3 (delta 0), reused 0 (delta 0) Unpacking objects: 100% (3/3), done. To /home/henryyan/submd/ws/../repos/lib1.git  * [new branch]      master -> master </pre>   初始化公共类库lib2： <pre class=" shell">➜ henryyan@hy-hp  ~/submd/ws/lib1 git:(master) cd .. ➜ henryyan@hy-hp  ~/submd/ws  git clone ../repos/lib2.git Cloning into lib2... done. warning: You appear to have cloned an empty repository. ➜ henryyan@hy-hp  ~/submd/ws  cd lib2 ➜ henryyan@hy-hp  ~/submd/ws/lib2 git:(master) echo "I'm lib2." > lib2-features ➜ henryyan@hy-hp  ~/submd/ws/lib2 git:(master) ✗ git add lib2-features ➜ henryyan@hy-hp  ~/submd/ws/lib2 git:(master) ✗ git commit -m "init lib2" [master (root-commit) c22aff8] init lib2  1 files changed, 1 insertions(+), 0 deletions(-)  create mode 100644 lib2-features ➜ henryyan@hy-hp  ~/submd/ws/lib2 git:(master) git push origin master Counting objects: 3, done. Writing objects: 100% (3/3), 227 bytes, done. Total 3 (delta 0), reused 0 (delta 0) Unpacking objects: 100% (3/3), done. To /home/henryyan/submd/ws/../repos/lib2.git  * [new branch]      master -> master </pre>   ### 2.2 为主项目添加Submodules   #### 2.2.1 为project1添加lib1和lib2 <pre class=" shell">➜ henryyan@hy-hp  ~/submd/ws/lib2 git:(master) cd ../project1 ➜ henryyan@hy-hp  ~/submd/ws/project1 git:(master) ls project-infos.txt ➜ henryyan@hy-hp  ~/submd/ws/project1 git:(master) git submodule add ~/submd/repos/lib1.git libs/lib1 Cloning into libs/lib1... done. ➜ henryyan@hy-hp  ~/submd/ws/project1 git:(master) ✗ git submodule add ~/submd/repos/lib2.git libs/lib2 Cloning into libs/lib2... done. ➜ henryyan@hy-hp  ~/submd/ws/project1 git:(master) ✗ ls libs  project-infos.txt ➜ henryyan@hy-hp  ~/submd/ws/project1 git:(master) ✗ ls libs lib1  lib2   ➜ henryyan@hy-hp  ~/submd/ws/project1 git:(master) ✗ git status # On branch master # Changes to be committed: #   (use "git reset HEAD <file>..." to unstage) # #   new file:   .gitmodules #   new file:   libs/lib1 #   new file:   libs/lib2 #   # 查看一下公共类库的内容   ➜ henryyan@hy-hp  ~/submd/ws/project1 git:(master) cat libs/lib1/lib1-features I'm lib1. ➜ henryyan@hy-hp  ~/submd/ws/project1 git:(master) cat libs/lib2/lib2-features I'm lib2. </pre> 好了，到目前为止我们已经使用**git submodule add**命令为**project1**成功添加了两个公共类库（lib1、lib2），查看了当前的状态发现添加了一个新文件(**.gitmodules**)和两个文件夹(libs/lib1、libs/lib2)；那么新增的**.gitmodules**文件是做什么用的呢？我们查看一下文件内容便知晓了： <pre class=" shell">n@hy-hp  ~/submd/ws/project1 git:(master) ✗ cat .gitmodules [submodule "libs/lib1"]     path = libs/lib1     url = /home/henryyan/submd/repos/lib1.git [submodule "libs/lib2"]     path = libs/lib2     url = /home/henryyan/submd/repos/lib2.git </pre> 原来如此，**.gitmodules**记录了每个submodule的引用信息，知道在当前项目的位置以及仓库的所在。   好的，我们现在把更改提交到仓库。 <pre class=" shell">➜ henryyan@hy-hp  ~/submd/ws/project1 git:(master) ✗ git commit -a -m "add submodules[lib1,lib2] to project1" [master 7157977] add submodules[lib1,lib2] to project1  3 files changed, 8 insertions(+), 0 deletions(-)  create mode 100644 .gitmodules  create mode 160000 libs/lib1  create mode 160000 libs/lib2   ➜ henryyan@hy-hp  ~/submd/ws/project1 git:(master) git push Counting objects: 5, done. Delta compression using up to 2 threads. Compressing objects: 100% (4/4), done. Writing objects: 100% (4/4), 491 bytes, done. Total 4 (delta 0), reused 0 (delta 0) Unpacking objects: 100% (4/4), done. To /home/henryyan/submd/ws/../repos/project1.git    45cbbcb..7157977  master -> master </pre>       假如你是第一次引入公共类库的开发人员，那么项目组的其他成员怎么Clone带有Submodule的项目呢，下面我们再clone一个项目讲解如何操作。   ### 2.3 Clone带有Submodule的仓库   模拟开发人员B…… <pre class=" shell">➜ henryyan@hy-hp  ~/submd/ws/project1 git:(master) cd ~/submd/ws ➜ henryyan@hy-hp  ~/submd/ws  git clone ../repos/project1.git project1-b Cloning into project1-b... done. ➜ henryyan@hy-hp  ~/submd/ws  cd project1-b ➜ henryyan@hy-hp  ~/submd/ws/project1-b git:(master) git submodule -c22aff85be91eca442734dcb07115ffe526b13a1 libs/lib1 -7290dce0062bd77df1d83b27dd3fa3f25a836b54 libs/lib2 </pre> 看到submodules的状态是hash码和文件目录，但是注意前面有一个减号：**-**，含义是该子模块还没有检出。   OK，检出project1-b的submodules…… <pre class=" shell">➜ henryyan@hy-hp  ~/submd/ws/project1-b git:(master) git submodule init Submodule 'libs/lib1' (/home/henryyan/submd/repos/lib1.git) registered for path 'libs/lib1' Submodule 'libs/lib2' (/home/henryyan/submd/repos/lib2.git) registered for path 'libs/lib2' ➜ henryyan@hy-hp  ~/submd/ws/project1-b git:(master) git submodule update Cloning into libs/lib1... done. Submodule path 'libs/lib1': checked out 'c22aff85be91eca442734dcb07115ffe526b13a1' Cloning into libs/lib2... done. Submodule path 'libs/lib2': checked out '7290dce0062bd77df1d83b27dd3fa3f25a836b54' </pre>       读者可以查看：.git/config文件的内容，最下面有submodule的注册信息！   验证一下类库的文件是否存在： <pre class=" shell">➜ henryyan@hy-hp  ~/submd/ws/project1-b git:(master) cat libs/lib1/lib1-features libs/lib2/lib2-features I'm lib1. I'm lib2. </pre>       上面的两个命令(git submodule init & update)其实可以简化，后面会讲到！   ### 2.3 修改Submodule   我们在开发人员B的项目上修改Submodule的内容。   先看一下当前Submodule的状态： <pre class=" shell">➜ henryyan@hy-hp  ~/submd/ws/project1-b git:(master) cd libs/lib1 ➜ henryyan@hy-hp  ~/submd/ws/project1-b/libs/lib1  git status # Not currently on any branch. nothing to commit (working directory clean) </pre> 为什么是**Not currently on any branch**呢？不是应该默认在**master**分支吗？别急，一一解答！   Git对于Submodule有特殊的处理方式，在一个主项目中引入了Submodule其实Git做了3件事情：   * 记录引用的仓库   * 记录主项目中Submodules的目录位置   * 记录引用Submodule的**commit id**   在**project1**中push之后其实就是更新了引用的commit id，然后project1-b在clone的时候获取到了submodule的commit id，然后当执行**git submodule update**的时候git就根据**gitlink**获取submodule的commit id，最后获取submodule的文件，所以clone之后不在任何分支上；但是master分支的commit id和HEAD保持一致。   查看~/submd/ws/project1-b/libs/lib1的引用信息： <pre class=" shell">➜ henryyan@hy-hp  ~/submd/ws/project1-b/libs/lib1  cat .git/HEAD c22aff85be91eca442734dcb07115ffe526b13a1 ➜ henryyan@hy-hp  ~/submd/ws/project1-b/libs/lib1  cat .git/refs/heads/master               c22aff85be91eca442734dcb07115ffe526b13a1 </pre>   现在我们要修改lib1的文件需要先切换到**master**分支： <pre class=" shell">➜ henryyan@hy-hp  ~/submd/ws/project1-b/libs/lib1  git checkout master Switched to branch 'master' ➜ henryyan@hy-hp  ~/submd/ws/project1-b/libs/lib1 git:(master) echo "add by developer B" >> lib1-features ➜ henryyan@hy-hp  ~/submd/ws/project1-b/libs/lib1 git:(master) ✗ git commit -a -m "update lib1-features by developer B" [master 36ad12d] update lib1-features by developer B  1 files changed, 1 insertions(+), 0 deletions(-) </pre>   在主项目中修改Submodule提交到仓库稍微繁琐一点，在**git push**之前我们先看看**project1-b**状态： <pre class=" shell">➜ henryyan@hy-hp  ~/submd/ws/project1-b git:(master) ✗ git status # On branch master # Changes not staged for commit: #   (use "git add <file>..." to update what will be committed) #   (use "git checkout -- <file>..." to discard changes in working directory) # #   modified:   libs/lib1 (new commits) # no changes added to commit (use "git add" and/or "git commit -a") </pre>   **libs/lib1 (new commits)**状态表示**libs/lib1**有新的提交，这个比较特殊，看看**project1-b**的状态： <pre class=" shell">➜ henryyan@hy-hp  ~/submd/ws/project1-b git:(master) ✗ git diff diff --git a/libs/lib1 b/libs/lib1 index c22aff8..36ad12d 160000 --- a/libs/lib1 +++ b/libs/lib1 @@ -1 +1 @@ -Subproject commit c22aff85be91eca442734dcb07115ffe526b13a1 +Subproject commit 36ad12d40d8a41a4a88a64add27bd57cf56c9de2 </pre>   从状态中可以看出**libs/lib1**的commit id由原来的**c22aff85be91eca442734dcb07115ffe526b13a1**更改为**36ad12d40d8a41a4a88a64add27bd57cf56c9de2**   <pre>注意：如果现在执行了git submodule update操作那么libs/lib1的commit id又会还原到c22aff85be91eca442734dcb07115ffe526b13a1，   这样的话刚刚的修改是不是就丢死了呢？不会，因为修改已经提交到了master分支，只要再git checkout master就可以了。 </pre>   现在可以把**libs/lib1**的修改提交到仓库了： <pre class=" shell">➜ henryyan@hy-hp  ~/submd/ws/project1-b git:(master) ✗ cd libs/lib1 ➜ henryyan@hy-hp  ~/submd/ws/project1-b/libs/lib1 git:(master) git push Counting objects: 5, done. Writing objects: 100% (3/3), 300 bytes, done. Total 3 (delta 0), reused 0 (delta 0) Unpacking objects: 100% (3/3), done. To /home/henryyan/submd/repos/lib1.git    c22aff8..36ad12d  master -> master </pre>   现在仅仅只完成了一步，下一步要提交**project1-b**引用submodule的commit id： <pre class=" shell">➜ henryyan@hy-hp  ~/submd/ws/project1-b/libs/lib1 git:(master) cd ~/submd/ws/project1-b ➜ henryyan@hy-hp  ~/submd/ws/project1-b git:(master) ✗ git add -u ➜ henryyan@hy-hp  ~/submd/ws/project1-b git:(master) ✗ git commit -m "update libs/lib1 to lastest commit id" [master c96838a] update libs/lib1 to lastest commit id  1 files changed, 1 insertions(+), 1 deletions(-) ➜ henryyan@hy-hp  ~/submd/ws/project1-b git:(master) git push Counting objects: 5, done. Delta compression using up to 2 threads. Compressing objects: 100% (3/3), done. Writing objects: 100% (3/3), 395 bytes, done. Total 3 (delta 0), reused 0 (delta 0) Unpacking objects: 100% (3/3), done. To /home/henryyan/submd/ws/../repos/project1.git    7157977..c96838a  master -> master </pre>   OK，大功高成，我们完成了Submodule的修改并把**libs/lib1**的最新commit id提交到了仓库。   接下来要看看**project1**怎么获取submodule了。   ### 2.4 更新主项目的Submodules   好的，让我们先进入**project1**目录同步仓库： <pre class=" shell">➜ henryyan@hy-hp  ~/submd/ws/project1-b git:(master) cd ../project1 ➜ henryyan@hy-hp  ~/submd/ws/project1 git:(master) git pull remote: Counting objects: 5, done. remote: Compressing objects: 100% (3/3), done. remote: Total 3 (delta 0), reused 0 (delta 0) Unpacking objects: 100% (3/3), done. From /home/henryyan/submd/ws/../repos/project1    7157977..c96838a  master     -> origin/master Updating 7157977..c96838a Fast-forward  libs/lib1 |    2 +-  1 files changed, 1 insertions(+), 1 deletions(-) ➜ henryyan@hy-hp  ~/submd/ws/project1 git:(master) ✗ git status # On branch master # Changes not staged for commit: #   (use "git add <file>..." to update what will be committed) #   (use "git checkout -- <file>..." to discard changes in working directory) # #   modified:   libs/lib1 (new commits) # no changes added to commit (use "git add" and/or "git commit -a") </pre>   我们运行了**git pull**命令和**git status**获取了最新的仓库源码，然后看到了状态时**modified**，这是为什么呢？   我们用**git diff**比较一下不同： <pre class=" shell">➜ henryyan@hy-hp  ~/submd/ws/project1 git:(master) ✗ git diff diff --git a/libs/lib1 b/libs/lib1 index 36ad12d..c22aff8 160000 --- a/libs/lib1 +++ b/libs/lib1 @@ -1 +1 @@ -Subproject commit 36ad12d40d8a41a4a88a64add27bd57cf56c9de2 +Subproject commit c22aff85be91eca442734dcb07115ffe526b13a1 </pre>   从diff的结果分析出来时因为submodule的commit id更改了，我们前面刚刚讲了要在主项目更新submodule的内容首先要提交submdoule的内容，然后再更新主项目中引用的submodulecommit id；现在我们看到的不同就是因为刚刚更改了project1-b的submodule commit id；好的，我来学习一下怎么更新**project1**的公共类库。   follow me……   <pre class=" shell">➜ henryyan@hy-hp  ~/submd/ws/project1 git:(master) ✗ git submodule update ➜ henryyan@hy-hp  ~/submd/ws/project1 git:(master) ✗ git status # On branch master # Changes not staged for commit: #   (use "git add <file>..." to update what will be committed) #   (use "git checkout -- <file>..." to discard changes in working directory) # #   modified:   libs/lib1 (new commits) # no changes added to commit (use "git add" and/or "git commit -a") </pre>   泥马，为什么没有更新？**git submodule update**命令不是更新子模块仓库的吗？   别急，先听我解释；因为子模块是在**project1**中引入的，**git submodule add ~/submd/repos/lib1.git libs/lib1**命令的结果，操作之后git只是把lib1的内容clone到了**project1**中，但是没有在仓库注册，证据如下： <pre class=" shell">➜ henryyan@hy-hp  ~/submd2/ws/project1 git:(master) ✗ cat .git/config [core]     repositoryformatversion = 0     filemode = true     bare = false     logallrefupdates = true [remote "origin"]     fetch = +refs/heads/*:refs/remotes/origin/*     url = /home/henryyan/submd/ws/../repos/project1.git [branch "master"]     remote = origin     merge = refs/heads/master </pre>   我们说过**git submodule init**就是在**.git/config**中注册子模块的信息，下面我们试试注册之后再更新子模块： <pre class=" shell">➜ henryyan@hy-hp  ~/submd/ws/project1 git:(master) ✗ git submodule init Submodule 'libs/lib1' (/home/henryyan/submd/repos/lib1.git) registered for path 'libs/lib1' Submodule 'libs/lib2' (/home/henryyan/submd/repos/lib2.git) registered for path 'libs/lib2' ➜ henryyan@hy-hp  ~/submd/ws/project1 git:(master) ✗ git submodule update remote: Counting objects: 5, done. remote: Total 3 (delta 0), reused 0 (delta 0) Unpacking objects: 100% (3/3), done. From /home/henryyan/submd/repos/lib1    c22aff8..36ad12d  master     -> origin/master Submodule path 'libs/lib1': checked out '36ad12d40d8a41a4a88a64add27bd57cf56c9de2'   ➜ henryyan@hy-hp  ~/submd/ws/project1 git:(master) cat .git/config [core]     repositoryformatversion = 0     filemode = true     bare = false     logallrefupdates = true [remote "origin"]     fetch = +refs/heads/*:refs/remotes/origin/*     url = /home/henryyan/submd/ws/../repos/project1.git [branch "master"]     remote = origin     merge = refs/heads/master [submodule "libs/lib1"]     url = /home/henryyan/submd/repos/lib1.git [submodule "libs/lib2"]     url = /home/henryyan/submd/repos/lib2.git   ➜ henryyan@hy-hp  ~/submd/ws/project1 git:(master) cat libs/lib1/lib1-features I'm lib1. add by developer B </pre>   上面的结果足以证明刚刚的推断，所以记得当需要更新子模块的内容时请先确保已经运行过**git submodule init**。   ### 2.5 为project2添加lib1和lib2   这个操作对于读到这里的你来说应该是**轻车熟路**了，action： <pre class=" shell">➜ henryyan@hy-hp  ~/submd/ws/project1 git:(master) cd ~/submd/ws/project2 ➜ henryyan@hy-hp  ~/submd/ws/project2 git:(master) git submodule add ~/submd/repos/lib1.git libs/lib1 Cloning into libs/lib1... done. ➜ henryyan@hy-hp  ~/submd/ws/project2 git:(master) ✗ git submodule add ~/submd/repos/lib2.git libs/lib2 zsh: correct 'libs/lib2' to 'libs/lib1' [nyae]? n Cloning into libs/lib2... done. ➜ henryyan@hy-hp  ~/submd/ws/project2 git:(master) ✗ ls libs  project-infos.txt ➜ henryyan@hy-hp  ~/submd/ws/project2 git:(master) ✗ git submodule init Submodule 'libs/lib1' (/home/henryyan/submd/repos/lib1.git) registered for path 'libs/lib1' Submodule 'libs/lib2' (/home/henryyan/submd/repos/lib2.git) registered for path 'libs/lib2'   ➜ henryyan@hy-hp  ~/submd/ws/project2 git:(master) ✗ git status # On branch master # Changes to be committed: #   (use "git reset HEAD <file>..." to unstage) # #   new file:   .gitmodules #   new file:   libs/lib1 #   new file:   libs/lib2 # ➜ henryyan@hy-hp  ~/submd/ws/project2 git:(master) ✗ git commit -a -m "add lib1 and lib2" [master 8dc697f] add lib1 and lib2  3 files changed, 8 insertions(+), 0 deletions(-)  create mode 100644 .gitmodules  create mode 160000 libs/lib1  create mode 160000 libs/lib2 ➜ henryyan@hy-hp  ~/submd/ws/project2 git:(master) git push Counting objects: 5, done. Delta compression using up to 2 threads. Compressing objects: 100% (4/4), done. Writing objects: 100% (4/4), 471 bytes, done. Total 4 (delta 0), reused 0 (delta 0) Unpacking objects: 100% (4/4), done. To /home/henryyan/submd/ws/../repos/project2.git    6e15c68..8dc697f  master -> master   </pre>   我们依次执行了添加submodule并commit和push到仓库，此阶段任务完成。   ### 2.6 修改lib1和lib2并同步到project1和project2   假如开发人员C同时负责**project1**和**project2**，有可能在修改**project1**的某个功能的时候发现lib1或者lib2的某个组件有bug需要修复，这个需求多模块和大型系统中经常遇到，我们应该怎么解决呢？   假如我的需求如下：   * 在lib1中添加一个文件：README，用来描述lib1的功能   * 在lib2中的lib2-features文件中添加一写文字：学习Git submodule的修改并同步功能   #### 2.6.1 在lib1中添加一个文件：README   <pre class=" shell">➜ henryyan@hy-hp  ~/submd/ws/project2 git:(master) cd libs/lib1 ➜ henryyan@hy-hp  ~/submd/ws/project2/libs/lib1 git:(master) echo "lib1 readme contents" > README ➜ henryyan@hy-hp  ~/submd/ws/project2/libs/lib1 git:(master) ✗ git add README ➜ henryyan@hy-hp  ~/submd/ws/project2/libs/lib1 git:(master) ✗ git commit -m "add file README" [master 8c666d8] add file README  1 files changed, 1 insertions(+), 0 deletions(-)  create mode 100644 README ➜ henryyan@hy-hp  ~/submd/ws/project2/libs/lib1 git:(master) git push Counting objects: 4, done. Delta compression using up to 2 threads. Compressing objects: 100% (2/2), done. Writing objects: 100% (3/3), 310 bytes, done. Total 3 (delta 0), reused 0 (delta 0) Unpacking objects: 100% (3/3), done. To /home/henryyan/submd/repos/lib1.git    36ad12d..8c666d8  master -> master </pre>   前面提到过现在仅仅只完成了一部分，我们需要在**project2**中再更新lib1的commit id： <pre class=" shell">➜ henryyan@hy-hp  ~/submd/ws/project2 git:(master) ✗ git status # On branch master # Changes not staged for commit: #   (use "git add <file>..." to update what will be committed) #   (use "git checkout -- <file>..." to discard changes in working directory) # #   modified:   libs/lib1 (new commits) # no changes added to commit (use "git add" and/or "git commit -a") ➜ henryyan@hy-hp  ~/submd/ws/project2 git:(master) ✗ git add libs/lib1 ➜ henryyan@hy-hp  ~/submd/ws/project2 git:(master) ✗ git commit -m "update lib1 to lastest commit id" [master ce1f3ba] update lib1 to lastest commit id  1 files changed, 1 insertions(+), 1 deletions(-) </pre>       我们暂时不push到仓库，等待和lib2的修改一起push。   #### 2.6.2 在lib2中的lib2-features文件添加文字 <pre class=" shell">➜ henryyan@hy-hp  ~/submd/ws/project2 git:(master) cd libs/lib2 ➜ henryyan@hy-hp  ~/submd/ws/project2/libs/lib2 git:(master) echo "学习Git submodule的修改并同步功能" >> lib2-features ➜ henryyan@hy-hp  ~/submd/ws/project2/libs/lib2 git:(master) ✗ git add lib2-features ➜ henryyan@hy-hp  ~/submd/ws/project2/libs/lib2 git:(master) ✗ git commit -m "添加文字：学习Git submodule的修改并同步功能" [master e372b21] 添加文字：学习Git submodule的修改并同步功能  1 files changed, 1 insertions(+), 0 deletions(-) ➜ henryyan@hy-hp  ~/submd/ws/project2/libs/lib2 git:(master) git push Counting objects: 5, done. Delta compression using up to 2 threads. Compressing objects: 100% (2/2), done. Writing objects: 100% (3/3), 376 bytes, done. Total 3 (delta 0), reused 0 (delta 0) Unpacking objects: 100% (3/3), done. To /home/henryyan/submd/repos/lib2.git    7290dce..e372b21  master -> master   ➜ henryyan@hy-hp  ~/submd/ws/project2/libs/lib2 git:(master) echo "学习Git submodule的修改并同步功能" >> lib2-features ➜ henryyan@hy-hp  ~/submd/ws/project2/libs/lib2 git:(master) ✗ git add lib2-features ➜ henryyan@hy-hp  ~/submd/ws/project2/libs/lib2 git:(master) ✗ git commit -m "添加文字：学习Git submodule的修改并同步功能" [master e372b21] 添加文字：学习Git submodule的修改并同步功能  1 files changed, 1 insertions(+), 0 deletions(-) ➜ henryyan@hy-hp  ~/submd/ws/project2/libs/lib2 git:(master) git push Counting objects: 5, done. Delta compression using up to 2 threads. Compressing objects: 100% (2/2), done. Writing objects: 100% (3/3), 376 bytes, done. Total 3 (delta 0), reused 0 (delta 0) Unpacking objects: 100% (3/3), done. To /home/henryyan/submd/repos/lib2.git    7290dce..e372b21  master -> master ➜ henryyan@hy-hp  ~/submd/ws/project2/libs/lib2 git:(master) cd - ~/submd/ws/project2 ➜ henryyan@hy-hp  ~/submd/ws/project2 git:(master) ✗ git status # On branch master # Your branch is ahead of 'origin/master' by 1 commit. # # Changes not staged for commit: #   (use "git add <file>..." to update what will be committed) #   (use "git checkout -- <file>..." to discard changes in working directory) # #   modified:   libs/lib2 (new commits) # no changes added to commit (use "git add" and/or "git commit -a") ➜ henryyan@hy-hp  ~/submd/ws/project2 git:(master) ✗ git add libs/lib2  ➜ henryyan@hy-hp  ~/submd/ws/project2 git:(master) ✗ git commit -m "update lib2 to lastest commit id" [master df344c5] update lib2 to lastest commit id  1 files changed, 1 insertions(+), 1 deletions(-) ➜ henryyan@hy-hp  ~/submd/ws/project2 git:(master) git status # On branch master # Your branch is ahead of 'origin/master' by 2 commits. # nothing to commit (working directory clean) ➜ henryyan@hy-hp  ~/submd/ws/project2 git:(master) git push Counting objects: 8, done. Delta compression using up to 2 threads. Compressing objects: 100% (6/6), done. Writing objects: 100% (6/6), 776 bytes, done. Total 6 (delta 0), reused 0 (delta 0) Unpacking objects: 100% (6/6), done. To /home/henryyan/submd/ws/../repos/project2.git    8dc697f..df344c5  master -> master </pre>   ### 2.7 同步project2的lib1和lib2的修改到project1   现在project2已经享受到了最新的代码带来的**快乐**，那么既然project1和project2属于同一个风格，或者调用同一个功能，要让这两个(可能几十个)项目保持一致。   <pre class=" shell">➜ henryyan@hy-hp  ~/submd/ws/project2 git:(master) cd ../project1 ➜ henryyan@hy-hp  ~/submd/ws/project1 git:(master) git pull Already up-to-date. </pre>   看看上面的结果对吗？为什么lib1和lib2更新了但是没有显示**new commits**呢？说到这里我记得刚刚开始学习的时候真得要晕死了，Git跟我玩捉迷藏游戏，为什么我明明提交了但是从**project1**更新不到任何改动呢？   帮大家分析一下问题，不过在分析之前先看看当前(project1和project2)的submodule状态： <pre class=" shell"># project2 的状态，也就是我们刚刚修改后的状态 ➜ henryyan@hy-hp  ~/submd/ws/project2 git:(master) git submodule  8c666d86531513dd1aebdf235f142adbac72c035 libs/lib1 (heads/master)  e372b21dffa611802c282278ec916b5418acebc2 libs/lib2 (heads/master)   # project1 的状态，等待更新submodules ➜ henryyan@hy-hp  ~/submd/ws/project1 git:(master) git submodule  36ad12d40d8a41a4a88a64add27bd57cf56c9de2 libs/lib1 (remotes/origin/HEAD)  7290dce0062bd77df1d83b27dd3fa3f25a836b54 libs/lib2 (heads/master) </pre>   两个项目有两个区别：   * commit id各不相同   * **libs/lib1**所处的分支不同   #### 2.7.1 更新project1的lib1和lib2改动   我们还记得刚刚在**project2**中修改的时候把lib1和lib2都切换到了master分支，目前project1中的lib1不在任何分支，我们先切换到master分支： <pre class=" shell">➜ henryyan@hy-hp  ~/submd/ws/project1 git:(master) cd libs/lib1 ➜ henryyan@hy-hp  ~/submd/ws/project1/libs/lib1  git checkout master Previous HEAD position was 36ad12d... update lib1-features by developer B Switched to branch 'master' Your branch is behind 'origin/master' by 1 commit, and can be fast-forwarded. ➜ henryyan@hy-hp  ~/submd/ws/project1/libs/lib1 git:(master) git pull remote: Counting objects: 4, done. remote: Compressing objects: 100% (2/2), done. remote: Total 3 (delta 0), reused 0 (delta 0) Unpacking objects: 100% (3/3), done. From /home/henryyan/submd/repos/lib1    36ad12d..8c666d8  master     -> origin/master Updating c22aff8..8c666d8 Fast-forward  README        |    1 +  lib1-features |    1 +  2 files changed, 2 insertions(+), 0 deletions(-)  create mode 100644 README ➜ henryyan@hy-hp  ~/submd/ws/project1/libs/lib1 git:(master) </pre>   果不其然，我们看到了刚刚在project2中修改的内容，同步到了project1中，当然现在更新了**project1**的**lib1**，commit id也会随之变动： <pre class=" shell">➜ henryyan@hy-hp  ~/submd/ws/project1/libs/lib1 git:(master) cd ../../ ➜ henryyan@hy-hp  ~/submd/ws/project1 git:(master) ✗ git status # On branch master # Changes not staged for commit: #   (use "git add <file>..." to update what will be committed) #   (use "git checkout -- <file>..." to discard changes in working directory) # #   modified:   libs/lib1 (new commits) # no changes added to commit (use "git add" and/or "git commit -a") ➜ henryyan@hy-hp  ~/submd/ws/project1 git:(master) ✗ git diff diff --git a/libs/lib1 b/libs/lib1 index 36ad12d..8c666d8 160000 --- a/libs/lib1 +++ b/libs/lib1 @@ -1 +1 @@ -Subproject commit 36ad12d40d8a41a4a88a64add27bd57cf56c9de2 +Subproject commit 8c666d86531513dd1aebdf235f142adbac72c035 </pre>   现在最新的commit id和project2目前的状态一致，说明真的同步了；好的，现在可以使用相同的办法更新**lib2**了： <pre class=" shell">➜ henryyan@hy-hp  ~/submd/ws/project1 git:(master) ✗ cd libs/lib2 ➜ henryyan@hy-hp  ~/submd/ws/project1/libs/lib2 git:(master) git pull remote: Counting objects: 5, done. remote: Compressing objects: 100% (2/2), done. remote: Total 3 (delta 0), reused 0 (delta 0) Unpacking objects: 100% (3/3), done. From /home/henryyan/submd/repos/lib2    7290dce..e372b21  master     -> origin/master Updating 7290dce..e372b21 Fast-forward  lib2-features |    1 +  1 files changed, 1 insertions(+), 0 deletions(-) </pre>   #### 2.7.2 更新project1的submodule引用   在**2.7.1**中我们更新了**project1**的**lib1**和**lib2**的最新版本，现在要把最新的commit id保存到**project1**中以保持最新的引用。 <pre class=" shell">➜ henryyan@hy-hp  ~/submd/ws/project1 git:(master) ✗ git status # On branch master # Changes not staged for commit: #   (use "git add <file>..." to update what will be committed) #   (use "git checkout -- <file>..." to discard changes in working directory) # #   modified:   libs/lib1 (new commits) #   modified:   libs/lib2 (new commits) # no changes added to commit (use "git add" and/or "git commit -a") ➜ henryyan@hy-hp  ~/submd/ws/project1 git:(master) ✗ git commit -a -m "update lib1 and lib2 commit id to new version" [master 8fcca50] update lib1 and lib2 commit id to new version  2 files changed, 2 insertions(+), 2 deletions(-) ➜ henryyan@hy-hp  ~/submd/ws/project1 git:(master) git push Counting objects: 5, done. Delta compression using up to 2 threads. Compressing objects: 100% (3/3), done. Writing objects: 100% (3/3), 397 bytes, done. Total 3 (delta 0), reused 0 (delta 0) Unpacking objects: 100% (3/3), done. To /home/henryyan/submd/ws/../repos/project1.git    c96838a..8fcca50  master -> master </pre>   ### 2.8 更新project1-b项目的子模块(使用脚本)   <pre class=" shell">➜ henryyan@hy-hp  ~/submd/ws/project1-b git:(master) git pull remote: Counting objects: 5, done. remote: Compressing objects: 100% (3/3), done. remote: Total 3 (delta 0), reused 0 (delta 0) Unpacking objects: 100% (3/3), done. From /home/henryyan/submd/ws/../repos/project1    c96838a..8fcca50  master     -> origin/master Updating c96838a..8fcca50 Fast-forward  libs/lib1 |    2 +-  libs/lib2 |    2 +-  2 files changed, 2 insertions(+), 2 deletions(-) ➜ henryyan@hy-hp  ~/submd/ws/project1-b git:(master) ✗ git status # On branch master # Changes not staged for commit: #   (use "git add <file>..." to update what will be committed) #   (use "git checkout -- <file>..." to discard changes in working directory) # #   modified:   libs/lib1 (new commits) #   modified:   libs/lib2 (new commits) # no changes added to commit (use "git add" and/or "git commit -a") </pre>   Git提示lib1和lib2有更新内容，这个判断的依据来源于submodule commit id的引用。   现在怎么更新呢？难道还是像project1中那样进入子模块的目录然后**git checkout master**，接着**git pull**？   而且现在仅仅才两个子模块、两个项目，如果在真实的项目中使用的话可能几个到几十个不等，再加上N个submodule，自己算一下要怎么更新多少个submodules？   例如笔者现在做的一个项目有**5**个web模块，每个web模块引用公共的css、js、images、jsp资源，这样就有20个submodule需要更新！！！   **工欲善其事，必先利其器**，写一个脚本代替手动任务。   #### 2.8.1 牛刀小试   <pre class=" shell">➜ henryyan@hy-hp  ~/submd/ws/project1-b git:(master) ✗ grep path .gitmodules | awk '{ print $3 }' > /tmp/study-git-submodule-dirs ➜ henryyan@hy-hp  ~/submd/ws/project1-b git:(master) ✗ cat /tmp/study-git-submodule-dirs  libs/lib1  libs/lib2 </pre>   我们通过分析**.gitmodules**文件得出子模块的路径，然后就可以根据这些路径进行更新。   #### 2.8.2 上路   <pre class=" shell">➜ henryyan@hy-hp  ~/submd/ws/project1-b git:(master) ✗ mkdir bin ➜ henryyan@hy-hp  ~/submd/ws/project1-b git:(master) ✗ vi bin/update-submodules.sh </pre>   把下面的脚本复制到**bin/update-submodules.sh**中： <pre class=" shell">#!/bin/bash grep path .gitmodules | awk '{ print $3 }' > /tmp/study-git-submodule-dirs   # read while read LINE do     echo $LINE     (cd ./$LINE && git checkout master && git pull) done < /tmp/study-git-submodule-dirs </pre>   稍微解释一下上面的脚本执行过程：   * 首先把子模块的路径写入到文件**/tmp/study-git-submodule-dirs**中；   * 然后读取文件中的子模块路径，依次切换到master分支(修改都是在master分支上进行的)，最后更新最近改动。   #### 2.8.3 <font color="red">2013-01-19更新</font>   网友**@紫煌**给出了更好的办法，一个命令就可以代替上面的**bin/update-submodules.sh**的功能：   <pre class="shell">git submodule foreach git pull </pre>   此命令也脚本一样，循环进入（enter）每个子模块的目录，然后执行**foreach**后面的命令。   > 该后面的命令可以任意的，例如 git submodule foreach ls -l 可以列出每个子模块的文件列表   #### 2.8.3 体验工具带来的便利   <pre class=" shell">➜ henryyan@hy-hp  ~/submd/ws/project1-b git:(master) ✗ git submodule +36ad12d40d8a41a4a88a64add27bd57cf56c9de2 libs/lib1 (heads/master) +7290dce0062bd77df1d83b27dd3fa3f25a836b54 libs/lib2 (heads/master)   # 添加执行权限 ➜ henryyan@hy-hp  ~/submd/ws/project1-b git:(master) ✗ chmod +x ./bin/update-submodules.sh ➜ henryyan@hy-hp  ~/submd/ws/project1-b git:(master) ✗ ./bin/update-submodules.sh libs/lib1 Already on 'master' remote: Counting objects: 4, done. remote: Compressing objects: 100% (2/2), done. remote: Total 3 (delta 0), reused 0 (delta 0) Unpacking objects: 100% (3/3), done. From /home/henryyan/submd/repos/lib1    36ad12d..8c666d8  master     -> origin/master Updating 36ad12d..8c666d8 Fast-forward  README |    1 +  1 files changed, 1 insertions(+), 0 deletions(-)  create mode 100644 README libs/lib2 Switched to branch 'master' remote: Counting objects: 5, done. remote: Compressing objects: 100% (2/2), done. remote: Total 3 (delta 0), reused 0 (delta 0) Unpacking objects: 100% (3/3), done. From /home/henryyan/submd/repos/lib2    7290dce..e372b21  master     -> origin/master Updating 7290dce..e372b21 Fast-forward  lib2-features |    1 +  1 files changed, 1 insertions(+), 0 deletions(-) ➜ henryyan@hy-hp  ~/submd/ws/project1-b git:(master) ✗ git submodule  8c666d86531513dd1aebdf235f142adbac72c035 libs/lib1 (heads/master)  e372b21dffa611802c282278ec916b5418acebc2 libs/lib2 (heads/master)    ➜ henryyan@hy-hp  ~/submd/ws/project1-b git:(master) ✗ git status # On branch master # Untracked files: #   (use "git add <file>..." to include in what will be committed) # #   bin/ nothing added to commit but untracked files present (use "git add" to track) </pre>   更新之后的两个变化：   * git submodule的结果和project2的submodule commit id保持一致；   * **project1-b**不再提示**new commits**了。   现在可以把工具添加到仓库了，当然你可以很骄傲的分享给其他项目组的同事。 <pre class=" shell">➜ henryyan@hy-hp  ~/submd/ws/project1-b git:(master) ✗ git add bin/update-submodules.sh ➜ henryyan@hy-hp  ~/submd/ws/project1-b git:(master) ✗ git commit -m "添加自动更新submodule的快捷脚本^_^" [master 756e788] 添加自动更新submodule的快捷脚本^_^  1 files changed, 9 insertions(+), 0 deletions(-)  create mode 100755 bin/update-submodules.sh ➜ henryyan@hy-hp  ~/submd/ws/project1-b git:(master) git push Counting objects: 5, done. Delta compression using up to 2 threads. Compressing objects: 100% (3/3), done. Writing objects: 100% (4/4), 625 bytes, done. Total 4 (delta 0), reused 0 (delta 0) Unpacking objects: 100% (4/4), done. To /home/henryyan/submd/ws/../repos/project1.git    8fcca50..756e788  master -> master </pre>   ### 2.9 新进员工加入团队，一次性Clone项目和Submodules   一般人使用的时候都是使用如下命令： <pre class=" shell">git clone /path/to/repos/foo.git git submodule init git submodule update </pre>       新员工不耐烦了，嘴上不说但是心里想：怎么那么麻烦？   上面的命令简直弱暴了，直接一行命令搞定： <pre class=" shell">git clone --recursive /path/to/repos/foo.git </pre>   –**recursive**参数的含义：可以在clone项目时同时clone关联的submodules。   git help 对其解释： <pre>--recursive, --recurse-submodules    After the clone is created, initialize all submodules within, using their default settings. This is equivalent to running git    submodule update --init --recursive immediately after the clone is finished. This option is ignored if the cloned repository    does not have a worktree/checkout (i.e. if any of --no-checkout/-n, --bare, or --mirror is given) </pre>   #### 2.9.1 使用一键方式克隆project2   <pre class=" shell">➜ henryyan@hy-hp  ~/submd/ws  git clone --recursive ../repos/project2.git project2-auto-clone-submodules Cloning into project2-auto-clone-submodules... done. Submodule 'libs/lib1' (/home/henryyan/submd/repos/lib1.git) registered for path 'libs/lib1' Submodule 'libs/lib2' (/home/henryyan/submd/repos/lib2.git) registered for path 'libs/lib2' Cloning into libs/lib1... done. Submodule path 'libs/lib1': checked out '8c666d86531513dd1aebdf235f142adbac72c035' Cloning into libs/lib2... done. Submodule path 'libs/lib2': checked out 'e372b21dffa611802c282278ec916b5418acebc2' </pre>   舒服……   ## 3.移除Submodule   **牢骚**：搞不明白为什么git不设计一个类似：git submodule remove的命令呢？   我们从project1.git克隆一个项目用来练习移除submodule： <pre class=" shell">➜ henryyan@hy-hp  ~/submd/ws  git clone --recursive ../repos/project1.git project1-remove-submodules Cloning into project1-remove-submodules... done. Submodule 'libs/lib1' (/home/henryyan/submd/repos/lib1.git) registered for path 'libs/lib1' Submodule 'libs/lib2' (/home/henryyan/submd/repos/lib2.git) registered for path 'libs/lib2' Cloning into libs/lib1... done. Submodule path 'libs/lib1': checked out '8c666d86531513dd1aebdf235f142adbac72c035' Cloning into libs/lib2... done. Submodule path 'libs/lib2': checked out 'e372b21dffa611802c282278ec916b5418acebc2' ➜ henryyan@hy-hp  ~/submd/ws  cd !$ ➜ henryyan@hy-hp  ~/submd/ws  cd project1-remove-submodules </pre>   ### 3.1 Step by   1、删除git cache和物理文件夹 <pre class=" shell">➜ henryyan@hy-hp  ~/submd/ws/project1-remove-submodules git:(master) git rm -r --cached libs/ rm 'libs/lib1' rm 'libs/lib2' ➜ henryyan@hy-hp  ~/submd/ws/project1-remove-submodules git:(master) ✗ rm -rf libs </pre>   2、删除.gitmodules的内容（或者整个文件） 因为本例只有两个子模块，直接删除文件： <pre class=" shell">➜ henryyan@hy-hp  ~/submd/ws/project1-remove-submodules git:(master) ✗ rm .gitmodules </pre>       如果仅仅删除某一个submodule那么打开.gitmodules文件编辑，删除对应submodule配置即可。   3、删除.git/config的submodule配置 源文件： <pre>[core]     repositoryformatversion = 0     filemode = true     bare = false     logallrefupdates = true [remote "origin"]     fetch = +refs/heads/*:refs/remotes/origin/*     url = /home/henryyan/submd/ws/../repos/project1.git [branch "master"]     remote = origin     merge = refs/heads/master [submodule "libs/lib1"]     url = /home/henryyan/submd/repos/lib1.git [submodule "libs/lib2"]     url = /home/henryyan/submd/repos/lib2.git </pre>   删除后： <pre>[core]     repositoryformatversion = 0     filemode = true     bare = false     logallrefupdates = true [remote "origin"]     fetch = +refs/heads/*:refs/remotes/origin/*     url = /home/henryyan/submd/ws/../repos/project1.git [branch "master"]     remote = origin     merge = refs/heads/master </pre>   4、提交更改 <pre class=" shell">➜ henryyan@hy-hp  ~/submd/ws/project1-remove-submodules git:(master) ✗ git status # On branch master # Changes to be committed: #   (use "git reset HEAD <file>..." to unstage) # #   deleted:    libs/lib1 #   deleted:    libs/lib2 # # Changes not staged for commit: #   (use "git add/rm <file>..." to update what will be committed) #   (use "git checkout -- <file>..." to discard changes in working directory) # #   deleted:    .gitmodules # ➜ henryyan@hy-hp  ~/submd/ws/project1-remove-submodules git:(master) ✗ git add .gitmodules ➜ henryyan@hy-hp  ~/submd/ws/project1-remove-submodules git:(master) ✗ git commit -m "删除子模块lib1和lib2" [master 5e2ee71] 删除子模块lib1和lib2  3 files changed, 0 insertions(+), 8 deletions(-)  delete mode 100644 .gitmodules  delete mode 160000 libs/lib1  delete mode 160000 libs/lib2 ➜ henryyan@hy-hp  ~/submd/ws/project1-remove-submodules git:(master) git push Counting objects: 3, done. Delta compression using up to 2 threads. Compressing objects: 100% (2/2), done. Writing objects: 100% (2/2), 302 bytes, done. Total 2 (delta 0), reused 0 (delta 0) Unpacking objects: 100% (2/2), done. To /home/henryyan/submd/ws/../repos/project1.git    756e788..5e2ee71  master -> master </pre>   ## 4.结束语   对于Git Submodule来说在刚刚接触的时候多少会有点凌乱的赶紧，尤其是没有接触过**svn:externals**。   本文从开始创建项目到使用git submodule的每个步骤以及细节、原理逐一讲解，希望到此读者能驾驭它。   学会了Git submdoule你的项目中再也不会出现大量重复的资源文件、公共类库，更不会出现多个版本，甚至一个客户的多个项目风格存在各种差异。   本文的写作来源于工作中的实践，如果您对于某个做法有更好的办法还请赐教，希望能留下您宝贵的意见。   <em>原创文章，转载请注明出处！</em> <em>[Git Submoudle使用完整教程--咖啡兔](http://www.kafeitu.me/git/2012/03/27/git-submodule.html)</em> </file></file></file></pre></file></pre></file></file></pre></file></file></pre></file></file></pre>