Issuing commands from c++ program to the shell

cyberfox007 · 01-31-2008, 07:23 PM

Hello all

I need to write a c++ program where when i run it it issues commands to the shell where i need to get information from /proc files like cpuinfo, version, and meminfo and have it displayed on the screen. how do i configure my c++ program to do this?

also are there any shell commands where it displays information about kernel and the current running process on the system?.

Thank You

paulsm4 · 01-31-2008, 09:09 PM

"man popen"
<= Standard C/C++ API for executing a shell command and reading the input

"man uname"
<= Gives kernel info

"man ps"
<= Gives process info

There are many, many, MANY alternatives to each of the above. Just Google around a little bit.

ludwig · 01-31-2008, 10:21 PM

I just tried "man popen" and I don't have any man pages regarding that topic installed on my system (I'm running a Debian 2.6.22 kernel). What package(s) do I need for this function? I googled "popen" and it looks pretty interesting...

ntubski · 01-31-2008, 11:48 PM

manpages-dev

gr.manju · 02-01-2008, 05:35 AM

hi

man proc
in proc man page check in which file you will get the required information (in proc directory)
just call cat filename command in system or execl
but make sure you have the root permission to cat files in proc directory
format the cat output to your convenience

or you can use commands which are already available

akhorus · 02-01-2008, 08:52 AM

Hi cyberfox007, I don't think you need to "configure" your C++ program in any special way.
You just open any file in the /proc directory for reading.
For example, in C, it would be something like:

fd = fopen("/proc/version","r");

Then you must parse the info you need from those files (just treat them as normal files)...
This links might help you:
http://linux.die.net/man/5/proc
http://search.cpan.org/src/VSEGO/Lin...1.00/stat.html

Some commands that will help you see the current running process on the system are 'ps' and 'top'.

TransAMrit · 02-01-2008, 10:17 AM

Also, you don't need to run a shell command and parse its output to find out about the running kernel - see "man 2 uname".

z940303 · 02-03-2008, 04:06 AM

The pstreams library is a general C++ solution (can be used for many applications).
Have not tested it out, will do soon.

http://pstreams.sourceforge.net/

Thanks for the interesting post.