This archive contains answers to questions sent to Unidata support through mid-2025. Note that the archive is no longer being updated. We provide the archive for reference; many of the answers presented here remain technically correct, even if somewhat outdated. For the most up-to-date information on the use of NSF Unidata software and data services, please consult the Software Documentation first.
Hello Andre, "Error: Can't open display" happens when a GEMPAK program tries but fails to connect to an X-windows server for the drawing or display of graphics. The environmental variable DISPLAY is not being found. As a normal/non-gempak user, you can check the definition of $DISPLAY with the command: echo $DISPLAY It will likely be ':0.0' or 'hostname:0.0'. If you switch to the gempak account with "su gempak" instead of "su - gempak" your current session envars (including $DISPLAY) will be carried to the gempak session. Try "su gempak" and "echo $DISPLAY" after confirming/setting $DISPLAY as the first user. Additionally, for ssh sessions to carry the X window system, use "ssh -XY user@host" instead of "ssh user@host". Michael James Unidata > Good morning. > > I have a GEMPAK installed with LDM on my Fedora. But I got this error > everytime I try to open nmap2 & or ntl & as GEMPAK user. But as a normal > user, I can open normally. > > What should I do? > > "Error: Can't open display" > > Ticket Details =================== Ticket ID: MQT-779038 Department: Support GEMPAK Priority: Normal Status: Open