telnet的なことをしたいときはsocketConnection()でコネクションをつくってそこにcat()とかwriteLines()とかすればいいらしい。以下はテキストでHTTPリクエストを投げる例。
con <- socketConnection("example.com", port = 80) req <- "GET / HTTP/1.1 Host: example.com " cat(req, file = con) readLines(con) #> [1] "HTTP/1.1 200 OK" #> [2] "Accept-Ranges: bytes" #> [3] "Cache-Control: max-age=604800" #> [4] "Content-Type: text/html" #> [5] "Date: Sat, 17 Sep 2016 10:34:30 GMT" #> [6] "Etag: \"359670651\"" #> [7] "Expires: Sat, 24 Sep 2016 10:34:30 GMT" #> [8] "Last-Modified: Fri, 09 Aug 2013 23:54:35 GMT" #> [9] "Server: ECS (pae/3796)" #> [10] "Vary: Accept-Encoding" #> [11] "X-Cache: HIT" #> [12] "x-ec-custom-error: 1" #> [13] "Content-Length: 1270" #> [14] "" #> [15] "<!doctype html>" #> [16] "<html>" #> [17] "<head>" #> [18] " <title>Example Domain</title>" #> [19] "" #> [20] " <meta charset=\"utf-8\" />" #> [21] " <meta http-equiv=\"Content-type\" content=\"text/html; charset=utf-8\" />" #> [22] " <meta name=\"viewport\" content=\"width=device-width, initial-scale=1\" />" #> [23] " <style type=\"text/css\">" #> [24] " body {" #> [25] " background-color: #f0f0f2;" #> [26] " margin: 0;" #> [27] " padding: 0;" #> [28] " font-family: \"Open Sans\", \"Helvetica Neue\", Helvetica, Arial, sans-serif;" #> [29] " " #> [30] " }" #> [31] " div {" #> [32] " width: 600px;" #> [33] " margin: 5em auto;" #> [34] " padding: 50px;" #> [35] " background-color: #fff;" #> [36] " border-radius: 1em;" #> [37] " }" #> [38] " a:link, a:visited {" #> [39] " color: #38488f;" #> [40] " text-decoration: none;" #> [41] " }" #> [42] " @media (max-width: 700px) {" #> [43] " body {" #> [44] " background-color: #fff;" #> [45] " }" #> [46] " div {" #> [47] " width: auto;" #> [48] " margin: 0 auto;" #> [49] " border-radius: 0;" #> [50] " padding: 1em;" #> [51] " }" #> [52] " }" #> [53] " </style> " #> [54] "</head>" #> [55] "" #> [56] "<body>" #> [57] "<div>" #> [58] " <h1>Example Domain</h1>" #> [59] " <p>This domain is established to be used for illustrative examples in documents. You may use this" #> [60] " domain in examples without prior coordination or asking for permission.</p>" #> [61] " <p><a href=\"http://www.iana.org/domains/example\">More information...</a></p>" #> [62] "</div>" #> [63] "</body>" #> [64] "</html>" close(con)
