I am trying to upload a file to the server. I am using windows while the server is running on linux. The path on my side is "D:\testfolder\testimage.jpg", and linux does not understand this path. How can I change this path so linux understands it.
There are multiple ways to upload a file to a server. The classic way is to use ftp.
Assuming your servers name is foo.bar, and you're logging into your home directory on the sever, and like to put the file into your folder testimage (does it exist?)
Once connected to the server, commands normally apply to the server, so let's change to the source-dir first:
if testfolder exists, omit the mkdir. Windows sometimes assumes you're up- or downloading text-files, not binaries. I'm not sure when and how to handle this - perhaps a switch /b like binary or a seperate command in ftp: