I am having a problem that I cannot browse the header files /libraries to get the implementation of the C functions like mssget, msgsnd, shmat etc.
How should I open these files?
If you are referring to the
sys/msg.h header file specifically, then it should be provided by the
libc6-dev development package
First make sure that the package is installed, either via the Software Center application or from a terminal using
sudo apt-get install libc6-dev
after which you should be able to browse the header file at
(for 32-bit systems) or
(for 64-bit systems).
To see the actual implementation of a library function, you will need to download the corresponding source code package: first, you will need to enable the relevant source repository (see How do I enable the source code repositories? if you don't know how to do that) and then, for example, in a directory of your choice
apt-get source libc6-dev
will download, unpack, and patch the source tarball into that directory (in this case, it will pick 'eglibc' as source package instead of 'libc6-dev'). However
msgsnd appear to be only stub functions - I don't know enough about Linux IPC to advise you beyond that.