Tools to Transform ‘cURL’ Command-Line Calls to ‘httr’ Requests

Description

Deciphering web/‘REST’ ‘API’ and ‘XHR’ calls can be tricky, which is one reason why internet browsers provide “Copy as cURL” functionality within their “Developer Tools”pane(s). These ‘cURL’ command-lines can be difficult to wrangle into an ‘httr’ ‘GET’ or ‘POST’ request, but you can now “straighten” these ‘cURLs’ either from data copied to the system clipboard or by passing in a vector of ‘cURL’ command-lines and getting back a list of parameter elements which can be used to form ‘httr’ requests. These lists can be passed to another function to automagically make ‘httr’ functions.

WIP

This is the path back to CRAN and to 1.0.0.

The V8 dependency has been removed and the package now uses docopt. This will make it easier to install on many systems and enable rapid addition of support for new cURL command-line parameters.

The “HAR” functions are not working well with the new methods but will be for full release.

What’s Inside The Tin

The following functions are implemented:

  • straighten: convert one or more “Copy as cURL” command lines into useful data
  • parse_query: parse URL query parameters into a named list
  • make_req: turn parsed cURL command lines into a httr request functions (i.e. returns working R functions)

The following functions are implemented:

Installation

devtools::install_github("hrbrmstr/curlconverter")

Usage

library(curlconverter)
library(jsonlite)
library(httr)

# current verison
packageVersion("curlconverter")
## [1] '1.0.0'

Simple example using a call to https://httpbin.org/headers:

httpbinrhcurl <- "curl 'https://httpbin.org/headers' -H 'pragma: no-cache' -H 'accept-encoding: gzip, deflate, sdch' -H 'accept-language: en-US,en;q=0.8' -H 'upgrade-insecure-requests: 1' -H 'user-agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_3) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/49.0.2623.39 Safari/537.36' -H 'accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8' -H 'cache-control: no-cache' -H 'referer: https://httpbin.org/' --compressed"

straight <- straighten(httpbinrhcurl)
## curl 'https://httpbin.org/headers' -H 'pragma: no-cache' -H 'accept-encoding: gzip, deflate, sdch' -H 'accept-language: en-US,en;q=0.8' -H 'upgrade-insecure-requests: 1' -H 'user-agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_3) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/49.0.2623.39 Safari/537.36' -H 'accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8' -H 'cache-control: no-cache' -H 'referer: https://httpbin.org/' --compressed
res <- make_req(straight)
## Error in warn_interactive() : 
##   To run write_clip() in non-interactive mode, either call write_clip() with allow_non_interactive = TRUE, or set the environment variable CLIPR_ALLOW=TRUE
# or 

straighten(httpbinrhcurl) %>% 
  make_req() -> res
## curl 'https://httpbin.org/headers' -H 'pragma: no-cache' -H 'accept-encoding: gzip, deflate, sdch' -H 'accept-language: en-US,en;q=0.8' -H 'upgrade-insecure-requests: 1' -H 'user-agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_3) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/49.0.2623.39 Safari/537.36' -H 'accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8' -H 'cache-control: no-cache' -H 'referer: https://httpbin.org/' --compressed
## Error in warn_interactive() : 
##   To run write_clip() in non-interactive mode, either call write_clip() with allow_non_interactive = TRUE, or set the environment variable CLIPR_ALLOW=TRUE
toJSON(content(res[[1]](), as="parsed"), auto_unbox = TRUE, pretty=TRUE)
## {
##   "headers": {
##     "Accept": "application/json, text/xml, application/xml, */*,text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8",
##     "Accept-Encoding": "gzip, deflate, sdch",
##     "Accept-Language": "en-US,en;q=0.8",
##     "Cache-Control": "no-cache",
##     "Host": "httpbin.org",
##     "Pragma": "no-cache",
##     "Referer": "https://httpbin.org/",
##     "Upgrade-Insecure-Requests": "1",
##     "User-Agent": "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_3) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/49.0.2623.39 Safari/537.36"
##   }
## }

Slightly more complex one:

toJSON(straighten("curl 'http://financials.morningstar.com/ajax/ReportProcess4HtmlAjax.html?&t=XNAS:MSFT&region=usa&culture=en-US&cur=&reportType=is&period=12&dataType=A&order=asc&columnYear=5&curYearPart=1st5year&rounding=3&view=raw&r=973302&callback=jsonp1454021128757&_=1454021129337' -H 'Cookie: JSESSIONID=5E43C98903E865D72AA3C2DCEF317848; sfhabit=asc%7Craw%7C3%7C12%7CA%7C5%7Cv0.14; ScrollY=0' -H 'DNT: 1' -H 'Accept-Encoding: gzip, deflate, sdch' -H 'Accept-Language: en-US,en;q=0.8' -H 'User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_3) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/47.0.2526.111 Safari/537.36' -H 'Accept: text/javascript, application/javascript, */*' -H 'Referer: http://financials.morningstar.com/income-statement/is.html?t=MSFT&region=usa&culture=en-US' -H 'X-Requested-With: XMLHttpRequest' -H 'Connection: keep-alive' -H 'Cache-Control: max-age=0' --compressed"), auto_unbox = TRUE, pretty=TRUE)
## curl 'http://financials.morningstar.com/ajax/ReportProcess4HtmlAjax.html?&t=XNAS:MSFT&region=usa&culture=en-US&cur=&reportType=is&period=12&dataType=A&order=asc&columnYear=5&curYearPart=1st5year&rounding=3&view=raw&r=973302&callback=jsonp1454021128757&_=1454021129337' -H 'Cookie: JSESSIONID=5E43C98903E865D72AA3C2DCEF317848; sfhabit=asc%7Craw%7C3%7C12%7CA%7C5%7Cv0.14; ScrollY=0' -H 'DNT: 1' -H 'Accept-Encoding: gzip, deflate, sdch' -H 'Accept-Language: en-US,en;q=0.8' -H 'User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_3) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/47.0.2526.111 Safari/537.36' -H 'Accept: text/javascript, application/javascript, */*' -H 'Referer: http://financials.morningstar.com/income-statement/is.html?t=MSFT&region=usa&culture=en-US' -H 'X-Requested-With: XMLHttpRequest' -H 'Connection: keep-alive' -H 'Cache-Control: max-age=0' --compressed
## [
##   {
##     "url": "http://financials.morningstar.com/ajax/ReportProcess4HtmlAjax.html?&t=XNAS:MSFT&region=usa&culture=en-US&cur=&reportType=is&period=12&dataType=A&order=asc&columnYear=5&curYearPart=1st5year&rounding=3&view=raw&r=973302&callback=jsonp1454021128757&_=1454021129337",
##     "method": "GET",
##     "cookies": {
##       "JSESSIONID": "5E43C98903E865D72AA3C2DCEF317848",
##       "sfhabit": "asc%7Craw%7C3%7C12%7CA%7C5%7Cv0.14",
##       "ScrollY": "0"
##     },
##     "username": {},
##     "password": {},
##     "user_agent": {
##       "DNT": "1",
##       "Accept-Encoding": "gzip, deflate, sdch",
##       "Accept-Language": "en-US,en;q=0.8",
##       "Accept": "text/javascript, application/javascript, */*",
##       "Referer": "http://financials.morningstar.com/income-statement/is.html?t=MSFT&region=usa&culture=en-US",
##       "X-Requested-With": "XMLHttpRequest",
##       "Connection": "keep-alive",
##       "Cache-Control": "max-age=0"
##     },
##     "referer": {},
##     "data": {},
##     "headers": {
##       "DNT": "1",
##       "Accept-Encoding": "gzip, deflate, sdch",
##       "Accept-Language": "en-US,en;q=0.8",
##       "User-Agent": "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_3) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/47.0.2526.111 Safari/537.36",
##       "Accept": "text/javascript, application/javascript, */*",
##       "Referer": "http://financials.morningstar.com/income-statement/is.html?t=MSFT&region=usa&culture=en-US",
##       "X-Requested-With": "XMLHttpRequest",
##       "Connection": "keep-alive",
##       "Cache-Control": "max-age=0"
##     },
##     "verbose": false,
##     "url_parts": {
##       "scheme": "http",
##       "hostname": "financials.morningstar.com",
##       "port": {},
##       "path": "ajax/ReportProcess4HtmlAjax.html",
##       "query": {
##         "1": "",
##         "t": "XNAS:MSFT",
##         "region": "usa",
##         "culture": "en-US",
##         "cur": "",
##         "reportType": "is",
##         "period": "12",
##         "dataType": "A",
##         "order": "asc",
##         "columnYear": "5",
##         "curYearPart": "1st5year",
##         "rounding": "3",
##         "view": "raw",
##         "r": "973302",
##         "callback": "jsonp1454021128757",
##         "_": "1454021129337"
##       },
##       "params": {},
##       "fragment": {},
##       "username": {},
##       "password": {}
##     },
##     "orig_curl": "curl 'http://financials.morningstar.com/ajax/ReportProcess4HtmlAjax.html?&t=XNAS:MSFT&region=usa&culture=en-US&cur=&reportType=is&period=12&dataType=A&order=asc&columnYear=5&curYearPart=1st5year&rounding=3&view=raw&r=973302&callback=jsonp1454021128757&_=1454021129337' -H 'Cookie: JSESSIONID=5E43C98903E865D72AA3C2DCEF317848; sfhabit=asc%7Craw%7C3%7C12%7CA%7C5%7Cv0.14; ScrollY=0' -H 'DNT: 1' -H 'Accept-Encoding: gzip, deflate, sdch' -H 'Accept-Language: en-US,en;q=0.8' -H 'User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_3) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/47.0.2526.111 Safari/537.36' -H 'Accept: text/javascript, application/javascript, */*' -H 'Referer: http://financials.morningstar.com/income-statement/is.html?t=MSFT&region=usa&culture=en-US' -H 'X-Requested-With: XMLHttpRequest' -H 'Connection: keep-alive' -H 'Cache-Control: max-age=0' --compressed"
##   }
## ]

There are some built-in test files you can play with:

(curl_line <- readLines(system.file("extdata/curl5.txt", package="curlconverter"), warn=FALSE))
## [1] "curl -i -X POST http://1.2.3.4/endpoint -H \"Content-Type:application/json\" -H 'key:abcdefg'"
toJSON(straighten(curl_line, quiet=TRUE), auto_unbox = TRUE, pretty=TRUE)
## [
##   {
##     "url": "http://1.2.3.4/endpoint",
##     "method": "POST",
##     "cookies": {},
##     "username": {},
##     "password": {},
##     "user_agent": {},
##     "referer": {},
##     "data": {},
##     "headers": {
##       "Content-Type": "application/json",
##       "key": "abcdefg"
##     },
##     "verbose": false,
##     "url_parts": {
##       "scheme": "http",
##       "hostname": "1.2.3.4",
##       "port": {},
##       "path": "endpoint",
##       "query": {},
##       "params": {},
##       "fragment": {},
##       "username": {},
##       "password": {}
##     },
##     "orig_curl": "curl -i -X POST http://1.2.3.4/endpoint -H \"Content-Type:application/json\" -H 'key:abcdefg'"
##   }
## ]
(curl_line <- readLines(system.file("extdata/curl8.txt", package="curlconverter"), warn=FALSE))
## [1] "curl 'https://research.stlouisfed.org/fred2/series/MKTGDPSAA646NWDB/downloaddata' -H 'Pragma: no-cache' -H 'Origin: https://research.stlouisfed.org' -H 'Accept-Encoding: gzip, deflate' -H 'Accept-Language: en-US,en;q=0.8' -H 'Upgrade-Insecure-Requests: 1' -H 'User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_3) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/49.0.2623.39 Safari/537.36' -H 'Content-Type: application/x-www-form-urlencoded' -H 'Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8' -H 'Cache-Control: no-cache' -H 'Referer: https://research.stlouisfed.org/fred2/series/MKTGDPSAA646NWDB/downloaddata' -H 'Connection: keep-alive' -H 'DNT: 1' --data 'form%5Bnative_frequency%5D=Annual&form%5Bunits%5D=lin&form%5Bfrequency%5D=Annual&form%5Baggregation%5D=Average&form%5Bobs_start_date%5D=1968-01-01&form%5Bobs_end_date%5D=2014-01-01&form%5Bfile_format%5D=csv&form%5Bdownload_data_2%5D=' --compressed"
# example with query parameters in the body
req <- straighten(curl_line, quiet=FALSE)
## curl 'https://research.stlouisfed.org/fred2/series/MKTGDPSAA646NWDB/downloaddata' -H 'Pragma: no-cache' -H 'Origin: https://research.stlouisfed.org' -H 'Accept-Encoding: gzip, deflate' -H 'Accept-Language: en-US,en;q=0.8' -H 'Upgrade-Insecure-Requests: 1' -H 'User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_3) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/49.0.2623.39 Safari/537.36' -H 'Content-Type: application/x-www-form-urlencoded' -H 'Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8' -H 'Cache-Control: no-cache' -H 'Referer: https://research.stlouisfed.org/fred2/series/MKTGDPSAA646NWDB/downloaddata' -H 'Connection: keep-alive' -H 'DNT: 1' --data 'form%5Bnative_frequency%5D=Annual&form%5Bunits%5D=lin&form%5Bfrequency%5D=Annual&form%5Baggregation%5D=Average&form%5Bobs_start_date%5D=1968-01-01&form%5Bobs_end_date%5D=2014-01-01&form%5Bfile_format%5D=csv&form%5Bdownload_data_2%5D=' --compressed
# ugh
(req[[1]]$data)
## [1] "form%5Bnative_frequency%5D=Annual&form%5Bunits%5D=lin&form%5Bfrequency%5D=Annual&form%5Baggregation%5D=Average&form%5Bobs_start_date%5D=1968-01-01&form%5Bobs_end_date%5D=2014-01-01&form%5Bfile_format%5D=csv&form%5Bdownload_data_2%5D="
#yay!
toJSON(parse_query(req[[1]]$data), auto_unbox = TRUE, pretty=TRUE)
## {
##   "form[native_frequency]": "Annual",
##   "form[units]": "lin",
##   "form[frequency]": "Annual",
##   "form[aggregation]": "Average",
##   "form[obs_start_date]": "1968-01-01",
##   "form[obs_end_date]": "2014-01-01",
##   "form[file_format]": "csv",
##   "form[download_data_2]": ""
## }

Spinning straw into gold

curl_line <- c('curl "http://anasim.iet.unipi.it/moniqa/php/from_js.php" -H "Origin: http://anasim.iet.unipi.it" -H "Accept-Encoding: gzip, deflate" -H "Accept-Language: it-IT,it;q=0.8,en-US;q=0.6,en;q=0.4" -H "User-Agent: Mozilla/5.0 (Windows NT 6.3; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/48.0.2564.103 Safari/537.36" -H "Content-Type: application/x-www-form-urlencoded; charset=UTF-8" -H "Accept: */*" -H "Referer: http://anasim.iet.unipi.it/moniqa/" -H "X-Requested-With: XMLHttpRequest" -H "Connection: keep-alive" --data "deviceid=65&function_name=extract_measurements" --compressed')

straighten(curl_line) %>% 
  make_req() -> get_data
## curl "http://anasim.iet.unipi.it/moniqa/php/from_js.php" -H "Origin: http://anasim.iet.unipi.it" -H "Accept-Encoding: gzip, deflate" -H "Accept-Language: it-IT,it;q=0.8,en-US;q=0.6,en;q=0.4" -H "User-Agent: Mozilla/5.0 (Windows NT 6.3; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/48.0.2564.103 Safari/537.36" -H "Content-Type: application/x-www-form-urlencoded; charset=UTF-8" -H "Accept: */*" -H "Referer: http://anasim.iet.unipi.it/moniqa/" -H "X-Requested-With: XMLHttpRequest" -H "Connection: keep-alive" --data "deviceid=65&function_name=extract_measurements" --compressed
## Error in warn_interactive() : 
##   To run write_clip() in non-interactive mode, either call write_clip() with allow_non_interactive = TRUE, or set the environment variable CLIPR_ALLOW=TRUE
cat(capture.output(get_data[[1]]), sep="\n")
## function () 
## httr::VERB(verb = "POST", url = "http://anasim.iet.unipi.it/moniqa/php/from_js.php", 
##     httr::add_headers(Origin = "http://anasim.iet.unipi.it", 
##         `Accept-Encoding` = "gzip, deflate", `Accept-Language` = "it-IT,it;q=0.8,en-US;q=0.6,en;q=0.4", 
##         `User-Agent` = "Mozilla/5.0 (Windows NT 6.3; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/48.0.2564.103 Safari/537.36", 
##         Accept = "*/*", Referer = "http://anasim.iet.unipi.it/moniqa/", 
##         `X-Requested-With` = "XMLHttpRequest", Connection = "keep-alive"), 
##     body = list(deviceid = "65", function_name = "extract_measurements"), 
##     encode = "form")
## <environment: 0x6996cc8>

That also sends this to the console and clipboard:

httr::VERB(
  verb = "GET", url = "http://anasim.iet.unipi.it/moniqa/php/from_js.php",
  httr::add_headers(
    Origin = "http://anasim.iet.unipi.it",
    `Accept-Encoding` = "gzip, deflate",
    `Accept-Language` = "it-IT,it;q=0.8,en-US;q=0.6,en;q=0.4",
    `User-Agent` = "Mozilla/5.0 (Windows NT 6.3; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/48.0.2564.103 Safari/537.36",
    Accept = "*/*", Referer = "http://anasim.iet.unipi.it/moniqa/",
    `X-Requested-With` = "XMLHttpRequest",
    Connection = "keep-alive"
  ),
  body = list(
    deviceid = "65",
    function_name = "extract_measurements"
  ),
  encode = "form"
)

Code of Conduct

Please note that this project is released with a Contributor Code of Conduct.

By participating in this project you agree to abide by its terms.