The basics of interacting with Unix

• You absolutely need the package OSProcess
• To get a reference to the process which is running your Cuis image do:

UnixProcess thisOSProcess .     "=>  a UnixProcess with pid 14751 "

• Then watch these interactions it should be all clear to you

". get the current working directory of the shell when it run Cuis "
UnixProcess thisOSProcess getCwd.     "=> '/home/p/prog/cuis-project' "

". get the pid of the Cuis process and his father pid "
UnixProcess thisOSProcess pid.        "=> 14751 "
UnixProcess thisOSProcess ppid.       "=> 14750 "

" ------------
from here on there are class method shortcuts that let you type less 
but the idea is alwys the same you are asking 'UnixProcess thisOSProcess' to 
give you info. 
 ------------ "

". get the environment variables of the shell who run Cuis "
UnixProcess env.  " => a Dictionary(#CLUTTER_IM_MODULE->'ibus' #COLORFGBG->'0;15' 
#COLORTERM->'truecolor' #DBUS_SESSION_BUS_ADDRESS->'unix:path=/run/user/1000/bus' .... 
#DESKTOP_SESSION->'plasma' #DISPLAY->':0.0' ) " 

". the program name corresponding to Cuis, which is the name of the OpenSmalltalkVM"
UnixProcess programName . 
"=> './sqcogspur64linuxht/lib/squeak/5.0-202003021730/squeak' "

" . the VM arguments, where there is Cuis image file and some extra parameters "
UnixProcess arguments . 
"=>  #('Cuis-Smalltalk-Dev/Cuis5.0-4975.image' '-d' 'Preferences veryBigFonts.') "

". get stdin, stdout, stderr "
". observe that by default, as of now, stdout and stdrr are both copied to Transcript 
   but only stderr will go printed into the shell which runs Cuis. "
UnixProcess stdOut nextPutAll: 'Hello world ! '. 
UnixProcess stdErr nextPutAll: 'Hello world ! '.