I write two new lines in a file. The new lines are appended to this file. How can print these two new lines to the console. Could you please give me some examples about this? The process is below: fd = open(file , O_WRONLY | O_APPEND, 0666); ret = read(0, buf, 100); write(file, buf, strlen(buf)); The problem …
Tag: linux
How to clear terminal window after TMOUT
I want to see if there is a way to have the terminal windows cleared after a TMOUT session timeout and disconnect. Does anyone know of a way to have the screen cleared once it times out? Answer Set an exit trap in your .bashrc file When the shell exits, it executes the clear command if TMOUT is set to
System crash with Linux CryptoApi Module
I tried to write Linux kernel module with cryptoapi. I found some examples like this: https://codedream.me/2014/04/cryptoapi-linux-kernel/ This example is working for me. Then I made some changes. Now my system crashes, when I try to load module. Can you help me with this? When variable len = 1000, module is …
Run console command with python
This code works fine directly in CLI: Now, I need to execute the same command but in Python environment. This is what I am trying: This is the error, and I am running the file and command from the same location: Answer you can just use os.system() if you have nothing else to do with spawned process. but, if y…
Ubuntu kernel kills CPLEX ILP process due to out of memory
I’m working with the ILOG CPLEX library in Java to solve an ILP problem. I’m using the default settings and did not adjust any parameters. I used the example code which I found online in samples for my main loop: I launched my jar on an Ubuntu 14 system with 24GB RAM and let it solve larger proble…
Why are the values in my dynamic 2D char array being overwritten?
I’m trying to build a process logger in C on Linux, but having trouble getting it right. I’d like it to have 3 colums: USER, PID, COMMAND. I’m using the output of ps aux and trying to dynamically append it to an array. That is, for every line ps aux outputs, I want to add a row to my array.
Cannot pass STDIN using shell_exec() in PHP
I am a complete beginner in PHP. I want to execute a java .jar file using PHP.The jar file takes input from STDIN and generates the output at STDOUT.To execute the jar file this is what I do in my Ubuntu Linux terminal: This works perfect.However when I replicate this in PHP as: This sends $p the output gener…
Get list of files that contain given text within directory given by pattern
I want to get a list of files that contain a given text within my file-system. Furthermore only files should be considdered that are located in a directoy given by a pattern. So let´s say I have a number of directories called myDir within my filelsystem as shown here: Now I want to get all the files within th…
ChefServer – Server returned error 502
I’m facing a problem during the Chef server configuration. When I install Chef server for the first time, everything goes well. Now, since I need to do some tests, when I uninstall Chef server and I try to install it again and add a new user, this happens: Probably is also worth to mention, that when I …
Many-to-one mapping of user threads to a kernel thread
As I understand it, in many-to-one mapping, one kernel thread manages many user threads. This kernel thread helps the user threads make system calls etc. What I don’t understand is: Why do we have many-to-one mapping if a single blocking call would block all user threads managed by the kernel thread ? I…