In a script I have a loop on N tests that runs a command in an xterm window for each test. N may be 30. With N =16 I have noticed that I have only 11 xterm windows for the first 11 tests were created.
For test 12 I got this error in my log file: "Xterm Xt error: Can't open display:..."
1- Is there any limitation on the number of xterm windows that can be opened simultaneously?
2- in my script how can I manage to check if the xterm window was opened without error (is there any way to do it without parsing my log file? )
The number of windows depends on your X server (not on the xterm program — or other clients, generally). Eleven windows sounds low (perhaps your machine has little memory).
To check for failure, your script should look at the exit-status (usually $?) when xterm exits. There are several possible codes, documented in the manual page.