My application running on embedded linux (busybox) tries to execute a script via popen(cmd, “r”). cmd = “sh /tmp/DF1_05/update.sh DF1_05” I can execute this script without problem launching it by hand from sh, but it fails when it’s launched by the application. The first lines of…
Tag: c++
Is there a way to lookup refcount for a kobject?
I expected to find a function along the lines of kobject_check_refcount, that returned the current refcount without altering it, in kobject.c, but as far as I can see there isn’t one. Is there such a function existing in the kernel source somewhere? I can see it being useful for debugging purposes at po…
init function not present in kallsyms
I wrote a simple hello world kernel module After loading the module, i am checking what all symbols are added into /proc/kallsysms. I don’t observe test_hello_init. Why don’t we have it Answer Using Linux kernel 5.8 source as a reference, the module’s symbol table for “kallsyms” …
How to select the interface used to perform a hostname lookup
I am working in an application embedded in a device running Linux and BusyBox. The hardware has 2 communication interfaces: Wi-Fi and 3G. In each connection, the application must try to connect using wi-fi first and, if it fails, the application tries again using 3G. I am forcing the connection to use the sel…
How can I fix this “undefined reference” error using G++ and CPLEX?
I apologize if this is not the correct community to ask this on, in that case, please tell me which one is. I tried some IBM forums but I get a (general?) error when I try to start a thread there. I am decently experienced with CPLEX (on Windows, with visual studio c++), but when I try to compile the
Running address of an application, followed by heap and stack expansions
I have an m.c: and an a.c: I compile and build these as: Then, I examine the executable, linux thus: objdump -drwxCS -Mintel linux The output of this on my Ubuntu 16.04.6 starts off with: start address 0x0000000000400540 then, later, is the init section: Finally, is the fini section: The program references th…
Linux SocketCAN behaviour of recvmsg
I’m writing a CAN logger program. The way I log the data is similar to the way the candump-tool is doing it when invoking candump like candump any: https://github.com/linux-can/can-utils/blob/master/candump.c candump any makes candump bind to any device, i.e. addr.can_ifindex = 0; then it uses recvmsg t…
Pipe between a C and a Python program
I am currently trying to write a C program that interacts with hardware, I have chosen so since the manufacturer of the hardware supplies with a C SDK for this hardware. However, I want this C program to output the data it receives from the hardware (a sensor for example) to a pipe so that I can write a Pytho…
DBus rejecting to send message to a custom service on the system bus
I’m writing a chatbot that (besides other features) allows the admin to send custom message to instant message apps via a DBus call. The chatbot creates a service org.cdpa.cdpachan on the system bus, exposes the interface org.cdpa.bot_send_message and the method send_message. I’m able to get any u…
execlp | try to run frok with execlp but all he the command after execlp not runing
I try to learn who fork and execlp work but encountered with unexpected behavior. I think i missing something. as can see in my code in the child process the printf command not execute just the execlp and then the parent process, why it’s that? my expected print is: pid.c 5 10 but i got: pid.c 10 Answer…