Using scala sys.process with single quotes, white-space, pipes etc - scala

Question

I am trying to use scala.sys.process._ to submit a POST request to my chronos server with curl. Because there is white space in the command's arguments, I am using the Seq[String] variant of cmd.!!
I am building the command like so:
val cmd = Seq("curl", "-L", "-X POST", "-H 'Content-Type: application/json'", "-d " + jsonHash, args.chronosHost + "/scheduler/" + jobType)
which produces, as expected,
cmd: Seq[String] = List(curl, -L, -X POST, -H 'Content-Type: application/json', -d '{"schedule":"R/2014-02-02T00:00:00Z/PT24H", "name":"Scala-Post-Test", "command":"which scalac", "epsilon":"PT15M", "owner":"myemail#thecompany.com", "async":false}', localhost:4040/scheduler/iso8601)
however, running this appears to mangle the 'Content-Type: application/json' argument:
scala> cmd.!!
% Total % Received % Xferd Average Speed Time Time Time Current
Dload Upload Total Spent Left Speed
100 264 0 100 100 164 2157 3538 --:--:-- --:--:-- --:--:-- 54666
res21: String =
"The HTTP header field "Accept" with value "*/* 'Content-Type:application/json'" could not be parsed.
"
which I don't understand. By contrast, calling cmd.mkString(" ") and copy+pasting into the terminal works as expected.
curl -L -X POST -H 'Content-Type:application/json' -d '{"schedule":"R/2014-02-02T00:00:00Z/PT24H", "name":"Scala-Post-Test", "command":"which scalac", "epsilon":"PT15M", "owner":"austin#quantifind.com", "async":false}' mapr-01.dev.quantifind.com:4040/scheduler/iso8601
I have tried numerous variations on the -H argument to no avail, any insight into using single quotes in sys.process._'s !! would be greatly appreciated.
I have tried variations on this as well, which generates a slew of errors, including
<h2>HTTP ERROR: 415</h2>
<p>Problem accessing /scheduler/iso8601. Reason:
<pre> Unsupported Media Type</pre></p>
<hr /><i><small>Powered by Jetty://</small></i>
(in addition to butchering the jsonHash, ie:
[1/6]: '"schedule":"R/2014-02-02T00:00:00Z/PT24H"' --> <stdout>
curl: (6) Couldn't resolve host ''"schedule"'
Which makes me think it is not interpreting the -H argument correctly

Answer 1

You need to split each argument into a separate element of a sequence.
Instead of this:
val cmd = Seq("curl", "-L", "-X POST", "-H 'Content-Type: application/json'", "-d " + jsonHash, args.chronosHost + "/scheduler/" + jobType)
you need to write this:
val cmd = Seq("curl", "-L", "-X", "POST", "-H", "'Content-Type: application/json'", "-d " + jsonHash, args.chronosHost + "/scheduler/" + jobType)
It puts each element of a sequence as an argument on a command line. So "-H 'Content-Type... looks like a single argument to curl while it should be 2.
Here is a simple way to test:
import scala.sys.process._
val cmd = Seq("find", "/dev/null", "-name", "null") // works
// does not work: val cmd = Seq("find", "/dev/null", "-name null")
val res = cmd.!!
println(res)

Answer 2

Most of the other answers are a bit faffy, use the following trick to get Bash to do all the quote handling etc etc for you
import scala.sys.process._
Seq("bash", "-c", bashLine) !
For easier Googling myself: bash execute process sys.process pipe string scala
As a String pimp method (easy copy pasting)
import scala.sys.process._
implicit class PimpedString(bashLine: String) {
def !!!: Int = Seq("bash", "-c", bashLine) !
}

Answer 3

I also had a hard time to make this work. Enlighten by Aleksey, below worked for me. Note that, surprisingly, there is no extra quote (or double quote) for Content-type:
val deploy = Seq("curl", "-X", "POST", s"$ip/v2/apps", "-H", "Content-Type: application/json", "-d", s"#$containerJson")
println(deploy.!!)