Drop-in replacement for base url that supports https, ftps,
gzip, deflate, etc. Default behavior is identical to url, but
request can be fully configured by passing a custom handle.
curl(url = "http://httpbin.org/get", open = "", handle = new_handle())
| url | character string. See examples. |
|---|---|
| open | character string. How to open the connection if it should be opened initially. Currently only "r" and "rb" are supported. |
| handle | a curl handle object |
As of version 2.3 curl connections support open(con, blocking = FALSE).
In this case readBin and readLines will return immediately with data
that is available without waiting. For such non-blocking connections the caller
needs to call isIncomplete to check if the download has completed
yet.
if (FALSE) { con <- curl("https://httpbin.org/get") readLines(con) # Auto-opened connections can be recycled open(con, "rb") bin <- readBin(con, raw(), 999) close(con) rawToChar(bin) # HTTP error curl("https://httpbin.org/status/418", "r") # Follow redirects readLines(curl("https://httpbin.org/redirect/3")) # Error after redirect curl("https://httpbin.org/redirect-to?url=http://httpbin.org/status/418", "r") # Auto decompress Accept-Encoding: gzip / deflate (rfc2616 #14.3) readLines(curl("http://httpbin.org/gzip")) readLines(curl("http://httpbin.org/deflate")) # Binary support buf <- readBin(curl("http://httpbin.org/bytes/98765", "rb"), raw(), 1e5) length(buf) # Read file from disk test <- paste0("file://", system.file("DESCRIPTION")) readLines(curl(test)) # Other protocols read.csv(curl("ftp://cran.r-project.org/pub/R/CRAN_mirrors.csv")) readLines(curl("ftps://test.rebex.net:990/readme.txt")) readLines(curl("gopher://quux.org/1")) # Streaming data con <- curl("http://jeroen.github.io/data/diamonds.json", "r") while(length(x <- readLines(con, n = 5))){ print(x) } # Stream large dataset over https with gzip library(jsonlite) con <- gzcon(curl("https://jeroen.github.io/data/nycflights13.json.gz")) nycflights <- stream_in(con) }