Opal Files
Yannick Marcon
2024-09-18
Opal has an
internal file system that is accessible through web services. The Opal R
package exposes files management related functions:
- upload a file or folder,
- download a file or folder (optionaly encrypted),
- move or rename a file or folder,
- create a folder,
- remove a file or folder,
- unzip a zip file into a folder,
- write a file to the remote R session workspace,
- read a file from the remote R session workspace.
Setup the connection with Opal:
library(opalr)
o <- opal.login("administrator", "password", "https://opal-demo.obiba.org")
Download a file:
opal.file_download(o, "/home/administrator/CNSIM.zip")
Download a file, protected by a password:
opal.file_download(o, "/home/administrator/CNSIM.zip", "CNSIM-encrypted.zip", key="ABCDEFGHIJKL")
Upload the file at another location:
opal.file_upload(o, "CNSIM.zip", "/projects/CNSIM")
Create a folder and list folder content:
fooDir <- paste0("/projects/CNSIM/foo-", sample(10000:99999, 1))
opal.file_mkdir(o, fooDir)
opal.file_ls(o, "/projects/CNSIM")
Move file to the new folder and list folder content:
opal.file_mv(o, "/projects/CNSIM/CNSIM.zip", fooDir)
opal.file_ls(o, fooDir)
Rename the new folder and list folder content:
barDir <- paste0("/projects/CNSIM/bar-", sample(10000:99999, 1))
opal.file_mv(o, fooDir, barDir)
opal.file_ls(o, "/projects/CNSIM")
Extract the content of the archive file into a folder:
out <- opal.file_unzip(o, paste0(barDir, "/CNSIM.zip"), barDir)
opal.file_ls(o, out)
Write a file from the Opal file system into the R server session
workspace:
opal.file_write(o, paste0(barDir, "/CNSIM.zip"))
opal.execute(o, "list.files()")
Read back the file into the Opal file system:
opal.file_read(o, "CNSIM.zip", paste0(barDir, "/ds.zip"))
opal.file_ls(o, barDir)
Remove created folder and list folder content:
opal.file_rm(o, barDir)
opal.file_ls(o, "/projects/CNSIM")
Good practice is to free server resources by sending a logout
request:
# clean server side
opal.logout(o)
# clean client side
unlink("CNSIM-encrypted.zip")
unlink("CNSIM.zip")