Skip to Content
Home » Questions » Recursively ftp download, then extract gz files

Recursively ftp download, then extract gz files

Submitted by J. Winchester on March 7, 2011

I have a multiple-step file download process I would like to do within R. I have got the middle step, but not the first and third...

# STEP 1 Recursively find all the files at an ftp site 
# <a href="ftp://prism.oregonstate.edu//pub/prism/pacisl/grids
all_paths" title="ftp://prism.oregonstate.edu//pub/prism/pacisl/grids
all_paths">ftp://prism.oregonstate.edu//pub/prism/pacisl/grids
all_paths</a> <- #### a recursive listing of the ftp path contents??? ####
 
# STEP 2 Choose all the ones whose filename starts with "hi"
all_files <- sapply(sapply(strsplit(all_paths, "/"), rev), "[", 1)
hawaii_log <- substr(all_files, 1, 2) == "hi"
hi_paths <- all_paths[hawaii_log]
hi_files <- all_files[hawaii_log]
 
# STEP 3 Download & extract from gz format into a single directory
mapply(download.file, url = hi_paths, destfile = hi_files)
## and now how to extract from gz format?