I don't know anything about netbeans, but: you can find out what's in a package installed on your system with the command
dpkg -L <name of package>
When I do this on an Ubuntu system I have access too, it indicates that libx11-dev is supposed to include the file /usr/include/X11/Xlib.h
. However, this does not tell you if the file actually exists. You need something like the find
commands you were trying for that.
Now, your find
commands didn't do anything because find
has a command line syntax that's different from everything else. This is how to do what you were trying to do with find
:
find / -name Xlib.h -print
find / -name X11 -print
(On recent systems with GNU userland (i.e. all Linux and some others), the trailing -print
is not necessary, but on older systems and possibly also those that retain more of a BSD heritage, it is. I learned my shell back in the bad old days of SunOS 4 and I still have those habits.)