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Tag: linux

difference between device file and device driver

I am currently reading the Linux Module Programming Guide and I have stumbled onto two terms that have confused a bit – device files and device driver. Upon goggling these terms I have come across the following- A device driver is a piece of software that operates or controls a particular type of device…

F_SETPIPE_SZ undeclared

I have included following headers: I have also tried to use before #include <unistd.h>, but it also does not help. I try to use fcntl and pass it F_SETPIPE_SZ as second argument, but I keep getting this error message: error: ‘F_SETPIPE_SZ’ undeclared (first use in this function) I actually found out tha…

Crontab not starting command on reboot

I need a command to run at reboot. This command is called script.sh This command pipes input to a python program I wrote called test.py. The problem is the program is not running when I check the processes.The syslog file states that it started the command on reboot, but it is not running. my crontab entry lo…

Potential issues of chmod 777 on a directory?

Assuming that I have this directory structure: /tmp/mysockets/appname/ What are the security drawbacks to doing chmod 777 on /tmp/mysockets/? Could another user delete or mess with the reference to the appname/ directory? What I want to do is allow other users to add their own directories to /tmp/mysockets/ b…

How to slow all time measurements of a process?

I’d like to make an application believe that time is going faster/slower than real time. I.e. I need to make all the time measurement APIs return t0+dt*s with user-defined s when t0+dt is real time. This would affect anything like gettimeofday() as well as timer_gettime() and all related functions and m…

How to use atomic variables in C?

I need to use an atomic variable in C as this variable is accessed across different threads. Don’t want a race condition. My code is running on CentOS. What are my options? Answer If you are using GCC on your CentOS platform, then you can use the __atomic built-in functions. Of particular interest might…

System commands in c#

Does C# have an equivalent to the system command in C? for example, how would I do this in c#?. I’m using Mono on Linux. Answer No problem I got it. Tested and working on Ubuntu 13.10