shell - Combine bash commands with each other -

i using following code execute bash command swift:

func runcommand(cmd : string, args : string...) -> (output: [string], error: [string], exitcode: int32) {      var output : [string] = []     var error : [string] = []      let task = nstask()     task.launchpath = cmd     task.arguments = args      let outpipe = nspipe()     task.standardoutput = outpipe     let errpipe = nspipe()     task.standarderror = errpipe      task.launch()      let outdata = outpipe.filehandleforreading.readdatatoendoffile()     if var string = string.fromcstring(unsafepointer(outdata.bytes)) {         string = string.stringbytrimmingcharactersinset(nscharacterset.newlinecharacterset())         output = string.componentsseparatedbystring("\n")     }      let errdata = errpipe.filehandleforreading.readdatatoendoffile()     if var string = string.fromcstring(unsafepointer(errdata.bytes)) {         string = string.stringbytrimmingcharactersinset(nscharacterset.newlinecharacterset())         error = string.componentsseparatedbystring("\n")     }      task.waituntilexit()     let status = task.terminationstatus      return (output, error, status) } 

credit: get terminal output after command swift

when run function following code:

runcommand("/sbin/ifconfig", args: "en1", "|", "grep", "ether") 

to simulate running following command shell:

ifconfig en1 | grep ether 

that result in output this:

ether xx:xx:xx:xx:xx:xx  

i following error:

ifconfig: |: bad value 

i'm guessing because commands aren't being combined , "|" symbol being interpreted direct argument ifconfig.

is there way simulate type of shell behaviour (the usage of "|" symbol filter output of command) within swift?

solved nhgrif's comment: combine bash commands each other