Why does WAVE crash, saying ``All pty's in use''?

This problem occurs if the installed version of the XView library requires BSD ptys, and if your operating system does not support BSD ptys. WAVE may operate without problems until you attempt to open a text or terminal window (by selecting Analyze... from the File menu, or by various selections from the Properties and Help menus. Typically, WAVE then exits with the error ``All pty's in use''.

Two types of ptys (pseudo-terminal devices) have been supported by most Linux distributions until recently. Traditionally, XView has used BSD-style ptys (pseudo-terminal devices) to implement text windows and terminal emulator objects such as WAVE's analysis commands window. Most recent Linux distributions based on version 2.6 kernels, including Fedora Core 2 and later, support only the newer UNIX98 (SVR4-style) ptys. Although some older XView libraries can be installed on these platforms, they will cause WAVE (and other XView-based applications) to crash whenever a text or terminal window is opened. The recommended solution is to install XView libraries that use UNIX98 (SVR4) ptys rather than the older BSD (``legacy'') ptys; these are available from PhysioNet.

George B. Moody (george@mit.edu)