npm文件应该在/usr/local/bin/npm.如果没有，请在他们的网站上重新安装node.js。这对我来说很管用。

完全移除节点:

  brew uninstall --force node

安装:

brew install node;
which node # => /usr/local/bin/node
export NODE_PATH='/usr/local/lib/node_modules'

I had the same issue,the reason for it was npm package manager was not installed while installing node. This was caused because of the following mistake: In the installation process there is a step called "Custom Setup", here you have the option to choose one of the following: 1) Node.js runtime (This is selected by default). 2) npm package manager 3) Online documentation shortcuts. 4) Add to Path. If you proceed as it is npm package manager will not be installed and hence you will get the error.

解决方案: 当你得到这些选项时，选择npm包管理器。 这对我很管用。

你可以通过为npm和node创建符号链接来解决这个问题，这是快速而简单的:

sudo ln -s $(which npm) /usr/local/bin/npm
sudo ln -s $(which node) /usr/local/bin/node

我使用which来获取位置，然后将其作为变量传递给命令，例如$(npm)。

我也为node创建了一个符号链接，因为npm依赖于 节点。

然后你就可以:

sudo npm -v

不需要重新安装节点或在整个目录上使用chmod。

我也有同样的问题;下面是修复它的命令:

Sudo ln -s /usr/local/bin/node /usr/bin/node Sudo ln -s /usr/local/lib/node /usr/lib/node Sudo ln -s /usr/local/bin/npm /usr/bin/npm Sudo ln -s /usr/local/bin/node-waf /usr/bin/node-waf

用于debian安装后的节点 输入

curl -k -O -L https://npmjs.org/install.sh    
ln -s /usr/bin/nodejs /usr/bin/node  
sh install.sh