Thanks, Vicamo!!

ASCII SPACE is okay on this case. (Please see below trial.)
However, emulator will hit Segmentation fault if "gsm call '\t'"

This part needs to be handled well.
Thanks again!!

gsm call <SP> (I tried gsm call '\u0020')
result:
gsm call  
KO: missing argument, try 'gsm call <phonenumber> [<numPresentation> [<name> [<namePresentation]]]'