ncurl

nano cURL - a minimalist http(s) client.

Usage

ncurl(
  url,
  convert = TRUE,
  follow = FALSE,
  method = NULL,
  headers = NULL,
  data = NULL,
  response = NULL,
  timeout = NULL,
  tls = NULL
)

Arguments

url: the URL address.
convert: [default TRUE] logical value whether to attempt conversion of the received raw bytes to a character vector. Set to FALSE if downloading non-text data.
follow: [default FALSE] logical value whether to automatically follow redirects (not applicable for async requests). If FALSE, the redirect address is returned as response header 'Location'.
method: (optional) the HTTP method as a character string. Defaults to 'GET' if not specified, and could also be 'POST', 'PUT' etc.
headers: (optional) a named character vector specifying the HTTP request headers, for example:
c(Authorization = "Bearer APIKEY", "Content-Type" = "text/plain")
A non-character or non-named vector will be ignored.
data: (optional) character string request data to be submitted. If a vector, only the first element is taken, and non-character objects are ignored.
response: (optional) a character vector specifying the response headers to return e.g. c("date", "server"). These are case-insensitive and will return NULL if not present. A non-character vector will be ignored.
timeout: (optional) integer value in milliseconds after which the transaction times out if not yet complete.
tls: (optional) applicable to secure HTTPS sites only, a client TLS Configuration object created by tls_config(). If missing or NULL, certificates are not validated.

Value

Named list of 3 elements:

$status - integer HTTP repsonse status code (200 - OK). Use status_code() for a translation of the meaning.
$headers - named list of response headers supplied in response, or NULL otherwise. If the status code is within the 300 range, i.e. a redirect, the response header 'Location' is automatically appended to return the redirect address.
$data - the response body, as a character string if convert = TRUE (may be further parsed as html, json, xml etc. as required), or a raw byte vector if FALSE (use writeBin() to save as a file).

Examples

ncurl("https://postman-echo.com/get",
       convert = FALSE,
       response = c("date", "content-type"),
       timeout = 1200L)
#> $status
#> [1] 200
#> 
#> $headers
#> $headers$date
#> [1] "Fri, 21 Mar 2025 16:11:21 GMT"
#> 
#> $headers$`content-type`
#> [1] "application/json; charset=utf-8"
#> 
#> 
#> $data
#>   [1] 7b 0a 20 20 22 61 72 67 73 22 3a 20 7b 7d 2c 0a 20 20 22 68 65 61 64 65 72
#>  [26] 73 22 3a 20 7b 0a 20 20 20 20 22 68 6f 73 74 22 3a 20 22 70 6f 73 74 6d 61
#>  [51] 6e 2d 65 63 68 6f 2e 63 6f 6d 22 2c 0a 20 20 20 20 22 78 2d 72 65 71 75 65
#>  [76] 73 74 2d 73 74 61 72 74 22 3a 20 22 74 31 37 34 32 35 37 33 34 38 31 2e 38
#> [101] 36 35 22 2c 0a 20 20 20 20 22 63 6f 6e 6e 65 63 74 69 6f 6e 22 3a 20 22 63
#> [126] 6c 6f 73 65 22 2c 0a 20 20 20 20 22 78 2d 66 6f 72 77 61 72 64 65 64 2d 70
#> [151] 72 6f 74 6f 22 3a 20 22 68 74 74 70 73 22 2c 0a 20 20 20 20 22 78 2d 66 6f
#> [176] 72 77 61 72 64 65 64 2d 70 6f 72 74 22 3a 20 22 34 34 33 22 2c 0a 20 20 20
#> [201] 20 22 78 2d 61 6d 7a 6e 2d 74 72 61 63 65 2d 69 64 22 3a 20 22 52 6f 6f 74
#> [226] 3d 31 2d 36 37 64 64 38 66 61 39 2d 35 62 36 61 38 39 63 63 34 32 37 64 66
#> [251] 39 38 35 31 66 39 33 36 38 37 33 22 0a 20 20 7d 2c 0a 20 20 22 75 72 6c 22
#> [276] 3a 20 22 68 74 74 70 73 3a 2f 2f 70 6f 73 74 6d 61 6e 2d 65 63 68 6f 2e 63
#> [301] 6f 6d 2f 67 65 74 22 0a 7d
#> 
ncurl("https://postman-echo.com/put",
      method = "PUT",
      headers = c(Authorization = "Bearer APIKEY"),
      data = "hello world",
      timeout = 1500L)
#> $status
#> [1] 200
#> 
#> $headers
#> NULL
#> 
#> $data
#> [1] "{\n  \"args\": {},\n  \"data\": \"hello world\",\n  \"files\": {},\n  \"form\": {},\n  \"headers\": {\n    \"host\": \"postman-echo.com\",\n    \"x-request-start\": \"t1742573482.027\",\n    \"connection\": \"close\",\n    \"content-length\": \"11\",\n    \"x-forwarded-proto\": \"https\",\n    \"x-forwarded-port\": \"443\",\n    \"x-amzn-trace-id\": \"Root=1-67dd8fa9-52e241a34948a052662640e8\",\n    \"authorization\": \"Bearer APIKEY\",\n    \"content-type\": \"application/json\"\n  },\n  \"json\": null,\n  \"url\": \"https://postman-echo.com/put\"\n}"
#> 
ncurl("https://postman-echo.com/post",
      method = "POST",
      headers = c(`Content-Type` = "application/json"),
      data = '{"key":"value"}',
      timeout = 1500L)
#> $status
#> [1] 200
#> 
#> $headers
#> NULL
#> 
#> $data
#> [1] "{\n  \"args\": {},\n  \"data\": {\n    \"key\": \"value\"\n  },\n  \"files\": {},\n  \"form\": {},\n  \"headers\": {\n    \"host\": \"postman-echo.com\",\n    \"x-request-start\": \"t1742573482.209\",\n    \"connection\": \"close\",\n    \"content-length\": \"15\",\n    \"x-forwarded-proto\": \"https\",\n    \"x-forwarded-port\": \"443\",\n    \"x-amzn-trace-id\": \"Root=1-67dd8faa-6c17913d2a5004cc05573fd8\",\n    \"content-type\": \"application/json\"\n  },\n  \"json\": {\n    \"key\": \"value\"\n  },\n  \"url\": \"https://postman-echo.com/post\"\n}"
#>

Usage

Arguments

Value

See also

Examples