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Return value of program invoked with system()

Posted on 2003-11-04
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Last Modified: 2010-04-22
Hi,
I'm writing a program that listens for network connections on a certain port.
Every X minutes it has to run a certain program (a program that I have written myself).
I do not wish to use cron or anything like it.
I invoke the program with the "system()" function and it works.
The only thing that annoys me is that I can't get hold of the return value of my program.

If I write this in my second program:

int main(...)
{
     ...
     if(...)
         return 999;
     ...
     return 666;
}

I want to use the return value for status purposes, how do I do this?
I want to be able to write something like this in my server program:

int runProgram()
{
    ...
    //INVOKE PROGRAM HERE
    switch (returnvalue)
    {
        case 666:
            ...
    }
    ...
}

Is this possible with the system() command?
If not, what should I use?

Thanks in advance,

Nicolas
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Question by:The_LowRider
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2 Comments
 
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Accepted Solution

by:
mtmike earned 250 total points
ID: 9680232
The system() command returns the exit code like wait() does:

status = system("...");
if (status >= 0) {
  exitcode = WEXITSTATUS(status);
}

The macro WEXITSTATUS is defined in <sys/wait.h>.

Note that exit codes must be small integers in the range 0-127.
0
 
LVL 1

Author Comment

by:The_LowRider
ID: 9680282
Exactly what I needed, thanks!
Works great!

Nicolas.
0

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