Para arquivos pequenos, tudo certo usando o exemplo de chamada da API que o dropbox fornece:
cpdropbox.sh
curl -X POST https://content.dropboxapi.com/2/files/upload \
--header "Authorization: Bearer qdas64*HEREISMYSECRETNUMBER*%@#$%@#$#@%@zUk" \
--header "Dropbox-API-Arg: {\"path\": \"/backup/$1\"}" \
--header "Content-Type: application/octet-stream" \
--data-binary @$1
O problema é que esse código funciona pra arquivos pequenos.
Mas pra arquivos grandes, dá OUT OF MEMORY.
--data-binary: out of memory
curl -X POST https://content.dropboxapi.com/2/files/upload \
--header "Authorization: Bearer qdas64*HEREISMYSECRETNUMBER*%@#$%@#$#@%@zUk" \
--header "Dropbox-API-Arg: {\"path\": \"/backup/$1\"}" \
--header "Content-Type: application/octet-stream" \
--header "Transfer-Encoding: chunked" --upload-file "$1"
No meu caso, um upload de 160MB.