我一般使用命令安装express。$npminstall-gexpress-generator然后bash提示安装成功/Users/majialun/.npm-global/bin/express->/Users/majialun/.npm-global/lib/node_modules/express-generator/bin/express-cli.js+express-generator@4.16.1在2.123s更新了1个包，然后运行??express。按道理这时候我应该可以创建项目了，但是系统提示：bash:express:commandnotfound其实不只是express，我自己写的脚本也有这个问题。全局安装成功，但是无法通过bash调用。调查一下，先看全局路径变量$echo$PATH然后有很多/Users/majialun/.rvm/gems/ruby-2.4.1/bin:/Users/majialun/.rvm/gems/ruby-2.4.1@global/bin:/Users/majialun/.rvm/rubies/ruby-2.4.1/bin:/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin:/Users/majialun/.rvm/gems/ruby-2.4.1/bin:/Users/majialun/.rvm/gems/ruby-2.4.1@global/bin:/Users/majialun/.rvm/rubies/ruby-2.4.1/bin:/Users/majialun/.rvm/bin:/Users/majialun/Documents/flutter/flutter/bin:/Users/majialun/.npm-global/bin/express:/Users/majialun/.rvm/bin:/Users/majialun/Documents/flutter/flutter/bin:/Users/majialun/.rvm/gems/ruby-2.4.1/bin:/Users/majialun/.rvm/gems/ruby-2.4.1@global/bin:/Users/majialun/.rvm/rubies/ruby-2.4.1/bin:/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin:/Users/majialun/.rvm/gems/ruby-2.4.1/bin:/Users/majialun/.rvm/gems/ruby-2.4.1@global/bin:/Users/majialun/.rvm/rubies/ruby-2.4.1/bin:/Users/majialun/.rvm/bin:/Users/majialun/Documents/flutter/flutter/bin:/Users/majialun/.npm-global/bin/express:/Users/majialun/.rvm/bin:/Users/majialun/.npm-global/bin:/Users/majialun/.rvm/gems/ruby-2.4.1/bin:/Users/majialun/.rvm/gems/ruby-2.4.1@global/bin:/Users/majialun/.rvm/rubies/ruby-2.4.1/bin:/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin:/Users/majialun/.rvm/gems/ruby-2.4.1/bin:/Users/majialun/.rvm/gems/ruby-2.4.1@global/bin:/Users/majialun/.rvm/rubies/ruby-2.4.1/bin:/Users/majialun/.rvm/bin:/Users/majialun/Documents/flutter/flutter/bin:/Users/majialun/.npm-global/bin/express:/Users/majialun/.rvm/bin:/Users/majialun/Documents/flutter/flutter/bin:/Users/majialun/.rvm/gems/ruby-2.4.1/bin:/Users/majialun/.rvm/gems/ruby-2.4.1@global/bin:/Users/majialun/.rvm/rubies/ruby-2.4.1/bin:/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin:/Users/majialun/.rvm/gems/ruby-2.4.1/bin:/Users/majialun/.rvm/gems/ruby-2.4.1@global/bin:/Users/majialun/.rvm/rubies/ruby-2.4.1/bin:/Users/majialun/.rvm/bin:/Users/majialun/Documents/flutter/flutter/bin这个时候我们发现太多了，但是不要慌，刚才安装Express的时候，有一个提示显示了npm的全查看局脚本挂在哪个路径，然后看安装成功提示：/Users/majialun/.npm-global/bin/express->/Users/majialun/.npm-global/lib/node_modules/express-generator/bin/express-cli.js+express-generator@4.16.1updated1packagein2.123s我们可以看到脚本安装在/Users/majialun/.npm-global/bin，这个目录包含所有的全局脚本，注意到bin目录，express只是这个目录之一。然后我们在全局路径中仔细查找，发现这个路径是不存在的。。。不知道怎么把路径弄丢了。我在公司的MacbookPro一切正常，但我随身携带的Macbook却不见了路径。解决方法我们直接进入根目录（/Users/majialun/），显示隐藏文件后，查看是否有.bash_profile，如果没有，新建一个，直接修改，添加路径:exportPATH=$PATH:/Users/majialun/.npm-global/bin:$PATH注意这个路径是从上面复制过来的，每个人的都不一样。总之，从安装成功的提示，复制到/bin，到这里结束。之后在终端输入source，然后把.bash_profile拖进去，就会有：$source/Users/majialun/.bash_profile执行，然后重启终端，运行试试：majialun$表示警告：the默认视图引擎在未来的版本中不会是jade警告：使用`--view=jade'或`--help'以获得额外的选项destinationisnotempty,continue?[y/N]没有notfound错误，问题解决。本文转载需征得作者同意，否则禁止转载。
