不需要从头写.gitignore文件，GitHub已经为我们准备了各种配置文件，只需要组合一下就可以使用了。所有配置文件可以直接在线浏览：https://github.com/github/gitignore
举个例子：
假设你在Windows下进行Python开发，Windows会自动在有图片的目录下生成隐藏的缩略图文件，如果有自定义目录，目录下就会有Desktop.ini文件，因此你需要忽略Windows自动生成的垃圾文件：
# Windows:
Thumbs.db
ehthumbs.db
Desktop.ini
然后，继续忽略Python编译产生的.pyc、.pyo、dist等文件或目录：
# Python:
*.py[cod]
*.so
*.egg
*.egg-info
dist
build
加上你自己定义的文件，最终得到一个完整的.gitignore文件，内容如下：
# Windows:
Thumbs.db
ehthumbs.db
Desktop.ini
# Python:
*.py[cod]
*.so
*.egg
*.egg-info
dist
build
# My configurations:
db.ini
deploy_key_rsa
最后一步就是把.gitignore也提交到Git，就完成了！当然检验.gitignore的标准是git status命令是不是说working directory clean。
使用Windows的童鞋注意了，如果你在资源管理器里新建一个.gitignore文件，它会非常弱智地提示你必须输入文件名，但是在文本编辑器里“保存”或者“另存为”就可以把文件保存为.gitignore了。
有些时候，你想添加一个文件到Git，但发现添加不了，原因是这个文件被.gitignore忽略了：
$ git add App.class
The following paths are ignored by one of your .gitignore files:
App.class
Use -f if you really want to add them.
如果你确实想添加该文件，可以用-f强制添加到Git：
$ git add -f App.class
或者你发现，可能是.gitignore写得有问题，需要找出来到底哪个规则写错了，可以用git check-ignore命令检查：
$ git check-ignore -v App.class
.gitignore:3:*.class App.class
Git会告诉我们，.gitignore的第3行规则忽略了该文件，于是我们就可以知道应该修订哪个规则。
小结
-
忽略某些文件时，需要编写
.gitignore； -
.gitignore文件本身要放到版本库里，并且可以对.gitignore做版本管理！
gitignore文件：
## Ignore Visual Studio temporary files, build results, and ## files generated by popular Visual Studio add-ons. # User-specific files *.suo *.user *.userosscache *.sln.docstates project.lock.json nugetpack.sh # User-specific files (MonoDevelop/Xamarin Studio) *.userprefs [Oo]utput/ [Ss]piders/ [Pp]ackages/ # Build results [Dd]ebug/ [Dd]ebugPublic/ [Rr]elease/ [Rr]eleases/ x64/ x86/ build/ bld/ [Bb]in/ [Oo]bj/ # Visual Studo 2015 cache/options directory .vs/ # MSTest test Results [Tt]est[Rr]esult*/ [Bb]uild[Ll]og.* # NUNIT *.VisualState.xml TestResult.xml # Build Results of an ATL Project [Dd]ebugPS/ [Rr]eleasePS/ dlldata.c *_i.c *_p.c *_i.h *.ilk *.meta *.obj *.pch *.pdb *.pgc *.pgd *.rsp *.sbr *.tlb *.tli *.tlh *.tmp *.tmp_proj *.log *.vspscc *.vssscc .builds *.pidb *.svclog *.scc # Chutzpah Test files _Chutzpah* # Visual C++ cache files ipch/ *.aps *.ncb *.opensdf *.sdf *.cachefile # Visual Studio profiler *.psess *.vsp *.vspx # TFS 2012 Local Workspace $tf/ # Guidance Automation Toolkit *.gpState # ReSharper is a .NET coding add-in _ReSharper*/ *.[Rr]e[Ss]harper *.DotSettings.user # JustCode is a .NET coding addin-in .JustCode # TeamCity is a build add-in _TeamCity* # DotCover is a Code Coverage Tool *.dotCover # NCrunch _NCrunch_* .*crunch*.local.xml # MightyMoose *.mm.* AutoTest.Net/ # Web workbench (sass) .sass-cache/ # Installshield output folder [Ee]xpress/ # DocProject is a documentation generator add-in DocProject/buildhelp/ DocProject/Help/*.HxT DocProject/Help/*.HxC DocProject/Help/*.hhc DocProject/Help/*.hhk DocProject/Help/*.hhp DocProject/Help/Html2 DocProject/Help/html # Click-Once directory publish/ # Publish Web Output *.[Pp]ublish.xml *.azurePubxml # TODO: Comment the next line if you want to checkin your web deploy settings # but database connection strings (with potential passwords) will be unencrypted *.pubxml *.publishproj # NuGet Packages *.nupkg # The packages folder can be ignored because of Package Restore **/packages/* # except build/, which is used as an MSBuild target. !**/packages/build/ # Uncomment if necessary however generally it will be regenerated when needed #!**/packages/repositories.config # Windows Azure Build Output csx/ *.build.csdef # Windows Store app package directory AppPackages/ # Others *.[Cc]ache ClientBin/ [Ss]tyle[Cc]op.* ~$* *~ *.dbmdl *.dbproj.schemaview *.pfx *.publishsettings node_modules/ bower_components/ # RIA/Silverlight projects Generated_Code/ # Backup & report files from converting an old project file # to a newer Visual Studio version. Backup files are not needed, # because we have git ;-) _UpgradeReport_Files/ Backup*/ UpgradeLog*.XML UpgradeLog*.htm # SQL Server files *.mdf *.ldf # Business Intelligence projects *.rdl.data *.bim.layout *.bim_*.settings # Microsoft Fakes FakesAssemblies/ # Node.js Tools for Visual Studio .ntvs_analysis.dat # Visual Studio 6 build log *.plg # Visual Studio 6 workspace options file *.opt # idea ignore .idea/ *.ipr *.iml *.iws # system ignore .DS_Store Thumbs.db
1、环境
Windows XP SP3 + TortoiseGit + msysGit
2、ignore files的三种方法
以下涉及的ignore文件均为如下格式：
#以'#'开始的行，被视为注释.
#忽略掉所有文件名是foo.txt的文件.
foo.txt
#忽略所有生成的html文件,
*.html
# foo.html是手工维护的，所以例外.
!foo.html
#忽略所有.o和.a文件.
*.[oa]
# 忽略*.o和*.a文件
*.[oa]
# 忽略*.b和*.B文件，my.b除外
*.[bB]
!my.b
# 忽略dbg文件和dbg目录
dbg
# 只忽略dbg目录，不忽略dbg文件
dbg/
# 只忽略dbg文件，不忽略dbg目录
dbg
!dbg/
# 只忽略当前目录下的dbg文件和目录，子目录的dbg不在忽略范围内
/dbg
参考：https://www.liaoxuefeng.com/wiki/0013739516305929606dd18361248578c67b8067c8c017b000/0013758404317281e54b6f5375640abbb11e67be4cd49e0000