SSIZE_MAX is defined by sys/limits.h which is included by limits.h. It's visiblitiy definitly depends on _ANSI_SOURCE and _C99_SOURCE not being defined anywhere, and it may also be invisible with some other _*_SOURCE macros and perhaps -ansi.... But I don't know if ANSI_SOURCE or C99_SOURCE should be defined or not. Does someone know what's going on? Franz