Hi I want to check the internet connection status (internet is connected / not connected) and wifi interface is up/down.

This I have to do from the Application developed in C which is running inside OpenWRT.

I have used POPEN and SYSTEM functions for this purpose. But all these functions are not running inside infinite loop.

Gives segmentation fault or hangs after several iterations.

I prefer of uses any OpenWRT system call/function or flag or register etc., to avoid the above situation.

Can Anyone help me on this?

What code are u using exactly?

popen() and system() functions must work in a infinite loop without problems, do you make a sleep() of some seconds in each iteration?

(Last edited by iasimov on 22 Jun 2016, 21:09)

Hi

Thanks for the reply.

Now even adding sleep, it is giving same issue....

I am running this on LinkIt Smart MT7688.

It is running only for 338 iteration always.

The code below for your reference.
while(1)
{
if((output = popen("/sbin/ifconfig apcli0 | grep 'inet addr' | wc -l","r"))==(FILE *) NULL)
                {

                        (void) fprintf (stderr, "popen failed - ifconfig\n");
                        pclose(output);
                        continue;
                }
                fscanf(output,"%u",&i);
                pclose(output);

<one more popen function to check internet connection>
........
........
........
sleep(3);
}

remove the first pclose, you are trying to close a null pointer.

and if u have problems with popen, u can redirect the output to a tmp file in /tmp, using system(), and read with fopen.

i.e:
system("sbin/ifconfig apcli0 | grep 'inet addr' | wc -l > /tmp/test1.tmp");
fptr = fopen("/tmp/test1.tmp", "r");
etc...

(Last edited by iasimov on 23 Jun 2016, 08:25)

It is behaving in the same way....after doing the above too....

  system("ifconfig apcli0 | grep 'inet addr' | wc -l > /tmp/testwifi.tmp");
                output = fopen("/tmp/testwifi.tmp", "r");
                fscanf(output,"%u",&i);
                fclose(output);