问题
Im new to NPM/Node and am trying to run a seeingly simple command but am having trouble.
Im using VS Code and have used the terminal to clone the GIT repo. Then 'npm install'.
I am trying to run the command in the documentation 'export MAPBOX_TOKEN=YOUR_MAPBOX_API_PUBLIC_TOKEN'
Based on the instructions on the NPM page https://www.npmjs.com/package/mapbox-map-image-export
To do this I type in 'node' then the command above. However I just get three dots appear?
回答1:
In Unix systems, export is a Shell built-in command used to mark a variable for automatic export to the environment of subsequently executed commands. The Windows (MS-DOS) equivalent command is set.
So, to set the Mapbox token in Windows, just open a command prompt and execute:
set MAPBOX_TOKEN=YOUR_MAPBOX_API_PUBLIC_TOKEN
You can then run mapbox-map-image-export in the same command prompt session, like this:
export-map mapbox://styles/mapbox/streets-v9 -w=11in -h=8.5in -b=-7.1354,57.9095,-6.1357,58.516 -t=%MAPBOX_TOKEN% -o=lewis.png
Note that in Windows, %NAME% is used to get a variable value, so it's %MAPBOX_TOKEN% (and not $MAPBOX_TOKEN).
You can also specify the Mapbox token directly in the export-map command, without setting an environment variable, e.g.:
export-map mapbox://styles/mapbox/streets-v9 -w=11in -h=8.5in -b=-7.1354,57.9095,-6.1357,58.516 -t=YOUR_MAPBOX_API_PUBLIC_TOKEN -o=lewis.png
回答2:
The command (export MAPBOX_TOKEN=YOUR_MAPBOX_API_PUBLIC_TOKEN) you saw in the documentation aims at being run in a shell, not the node REPL.
Its job is to configure the token which can then be used by this package CLI. Technically it means:
Define an environment variable accessible to all the upcoming processes named MAPBOX_TOKEN with the value YOUR_MAPBOX_API_PUBLIC_TOKEN.
Executing it in a shell will enable the export-map command to grab it through process.env.
来源：https://stackoverflow.com/questions/45758253/running-npm-mapbox-map-image-export