hey!!

how do I access system variables (e.g. username, date, kernel version, etc. etc.) from a c++ program? Or does anyone know of any good sites I could check to see more on this?? I just want to be able to issue such shell commands as uname and who, but from a c++ program. Or could I just fork and exec these shell commands from my c++ program?? Ok, I'm rambling.... Can anyone help me out??

Thanks,
Gearóid

You can get this info mainly from the files and directories in /proc. All programs like ps, uname, top, free, vmstat, etc. read their information from the files in /proc.

Just read and parse the information from the files in /proc, or e.g. to see who is the owner of PID 850, call stat() on the file /proc/850.

See "man proc" for more info about the format of the files in /proc.
Maybe also read "man utmp" for info about users logging in and out.
Yes, that would work also. But it's ugly and inefficient. Use popen() (or some C++ equivalent if it exists) instead of fork() and the exec() family of functions.

'man 2 uname' for the system call uname.

hey, thanks.

So I can just open these system files and read the contents as if they were just regular text files? So I'll mostly be using the fstream library and reading from all of these various system files to get whatever system variables I need?

Cool, thanks for the help.

Yes