npm install ionic cordova -g

在此之前遇到的:node配置环境变量，除了系统变量的path,用户变量里的Path也要改呀，不然默认就给你甩到C:\Users\YourName\AppData\Roaming\这里来了

1. 直接使用命令npm install ionic cordova -g下载特别慢，有时日志里出现connect timeout 连接超时

解决：使用cnpm.       cnpm跟npm用法完全一致，只是在执行命令时将npm改为cnpm。

安装：npm install cnpm -g --registry=https://registry.npm.taobao.org

  测试：安装完后最好查看其版本号cnpm -v或关闭命令提示符重新打开，安装完直接使用有可能会出现错误 

使用: cnpm install ionic cordova -g 

2.不知怎么搞得ionic没有了，ionic -v 时提示“不是内部命令外部命令blabla...”，于是重新npm install ionic -g, 结果居然是说没有写入权限？

并且报错

1803 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\ci-info
1804 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\bytes
1805 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\buffer-crc32
1806 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\ansi-styles
1807 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\concat-map
1808 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\continuable-cache
1809 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\core-util-is
1810 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\crc
1811 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\delayed-stream
1812 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\combined-stream
1813 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\dargs
1814 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\destroy
1815 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\ee-first
1816 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\escape-string-regexp
1817 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\etag
1818 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\extend
1819 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\figures
1820 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\fresh
1821 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\fs.realpath
1822 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\has-flag
1823 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\iconv-lite
1824 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\inherits
1825 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\block-stream
1826 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\ipaddr.js
1827 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\is-dotfile
1828 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\is-fullwidth-code-point
1829 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\is-glob
1830 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\glob-parent
1831 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\glob-base
1832 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\is-primitive
1833 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\is-promise
1834 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\isarray
1835 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\isobject
1836 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\kind-of
1837 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\livereload-js
1838 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\lodash
1839 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\lodash._basecopy
1840 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\lodash._getnative
1841 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\lodash._isiterateecall
1842 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\lodash.isarguments
1843 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\lodash._createassigner
1844 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\lodash.assign
1845 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\mime
1846 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\mime-db
1847 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\mimic-fn
1848 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\debug
1849 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\accepts
1850 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\object.omit
1851 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\on-finished
1852 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\opn
1853 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\os-tmpdir
1854 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\proxy-middleware
1855 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\proxy-addr
1856 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\regex-cache
1857 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\remove-trailing-separator
1858 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\expand-range
1859 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\micromatch
1860 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\anymatch
1861 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\leek
1862 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\safe-buffer
1863 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\sax
1864 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\semver
1865 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\rx-lite-aggregates
1866 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\shebang-regex
1867 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\restore-cursor
1868 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\slice-ansi
1869 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\ssh-config
1870 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\statuses
1871 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\cli-cursor
1872 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\string-template
1873 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\string-width
1874 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\supports-color
1875 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\chalk
1876 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\through
1877 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\external-editor
1878 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\tslib
1879 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\ultron
1880 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\type-is
1881 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\unpipe
1882 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\finalhandler
1883 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\inquirer
1884 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\raw-body
1885 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\body-parser
1886 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\util-deprecate
1887 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\readable-stream
1888 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\bl
1889 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\crc32-stream
1890 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\compress-commons
1891 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\readdirp
1892 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\express
1893 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\faye-websocket
1894 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\wrappy
1895 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\win-release
1896 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\once
1897 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\end-of-stream
1898 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\inflight
1899 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\archiver-utils
1900 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\fstream
1901 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\tar
1902 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\ws
1903 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\yallist
1904 warn checkPermissions Missing write access to E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\zip-stream
1905 verbose stack Error: ENOENT: no such file or directory, access 'E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\ci-info'
1906 verbose cwd C:\Windows\system32
1907 verbose Windows_NT 10.0.15063
1908 verbose argv "E:\\TOOLS\\NodeJs\\node.exe" "E:\\TOOLS\\NodeJs\\node_modules\\npm\\bin\\npm-cli.js" "install" "-g" "cordova" "ionic"
1909 verbose node v8.5.0
1910 verbose npm  v5.3.0
1911 error path E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\ci-info
1912 error code ENOENT
1913 error errno -4058
1914 error syscall access
1915 error enoent ENOENT: no such file or directory, access 'E:\TOOLS\NodeJs\node_global\node_modules\ionic\node_modules\ci-info'
1916 error enoent This is related to npm not being able to find a file.
1917 verbose exit [ -4058, true ]

找不到这个文件，可是这就是没权限写入的第一个文件么，当手动创建了这个文件，还会报下一个文件的。所以我猜根本问题还是npm install时的问题，于是换了管理员身份登陆，结果，，还是这样.

解决：最后突然想起之前用的cnpm，试了一下 cnpm install ionic -g，就成功了。

到最后也没明白这怎么会和权限问题有关系。