# ListenChar() and GetChar() fail under "matlab -nodesktop" **URL:** \ **Category:** Uncategorized\ **Created:** [August 29, 2007, 8:31am UTC](https://psychtoolbox.discourse.group/t/listenchar-and-getchar-fail-under-quot-matlab-nodesktop-quot/1025 "2007-08-29T08:31:01Z")\ **Posts on this page:** 1\ **Page:** 1
**Author:** ![e\_flister](https://avatars.discourse-cdn.com/v4/letter/e/e36b37/32.png) [@e\_flister](https://psychtoolbox.discourse.group/u/e_flister)\ **Post date:** [August 29, 2007, 8:31am UTC](https://psychtoolbox.discourse.group/t/listenchar-and-getchar-fail-under-quot-matlab-nodesktop-quot/1025/1 "2007-08-29T08:31:01Z")
hey mario- (using winxp sp2, 2007a, 3.0.8.148604056) i'm trying to run some code that uses ListenChar()/GetChar() from a matlab started under "-nodesktop". i try typing into my commandwindow and neither ListenChar(2) nor GetChar(0) works -- the characters just appear in the commandwindow and are not detected by the code. in a matlab started without "-nodesktop", everything is fine. if i try to execute the test from line 66 of PsychBasic\ListenChar.m (or line 225 of PsychBasic\GetChar.m), i get: > \>\> exist('commandwindow', 'builtin') ans = 0 even though: > \>\> which commandwindow C:\MATLAB\R2007a\toolbox\matlab\codetools\commandwindow.m note that: > \>\> exist('commandwindow') ans = 2 > \>\> help exist EXIST Check if variables or functions are defined. EXIST('A') returns: 0 if A does not exist 1 if A is a variable in the workspace 2 if A is an M-file on MATLAB's search path. It also returns 2 when A is the full pathname to a file or when A is the name of an ordinary file on MATLAB's search path [...] thus, the line that follows the builtin test for commandwindow in both files: "builtin('commandwindow', msg);" yields: ??? Cannot find builtin function 'commandwindow' (this assumes the variable 'msg' was defined, which it is not). SO. if i disable the tests and just execute "commandwindow," focus does indeed get sucked to my (nondesktop) commandwindow. but this does not rescue the "-nodesktop" function. also note, under "-nodesktop": » usejava('jvm') ans = 1 » usejava('awt') ans = 1 » usejava('swing') ans = 1 » usejava('desktop') ans = 0 -erik