Such flags as O_DIRECT, O_SYNC, O_DSYNC can be used to specify synchronous / asynchronous IO at the time when descriptor is created (create syscall). But is it possible to use this flags for distinct write (or similar) syscalls in order to make some of them synchronous? Answer is it possible to use this flags…
How to install R library “ggpubr” in a Docker image?
I tried to install the R library ggpubr in a docker image. I pulled the r-base:3.6.3 and the following is my Dockerfile: and here is my Rinstall_packages.R file: each time I got the output like this: I tried to install the library in batch mode: It works. However, after I exited the bash, I still can not use …
C/C++: POSIX compatible way to find default network interface up/down
I’m working on POSIX platform (PSE51 to be exact). I want to get notified when the default network interface goes up/down (via a callback or through continuous poll). The challenge is that I could find a linux specific way to get the default interface here and found a linux specific way to find the netw…
Missing ‘=’. in Debian service [closed]
Closed. This question does not meet Stack Overflow guidelines. It is not currently accepting answers. This question does not appear to be about a specific programming problem, a software algorithm, or software tools primarily used by programmers. If you believe the question would be on-topic on another Stack …
How to install Python package installer PIP on Ubuntu 20.04 Linux
Trying to install pip with Ubuntu version 20.04, Python version 3.8 on my Oracle virtual box. Tried everything to install pip but failed Steps tried Also tried Error both times python3-pip is not available but is being used by another candidate. This may mean that the package has been obsolete, has been missi…
How to declare a global variable in an header file and how he need to be in the c file
i have a serious problem to understand how to declare a global variable in an header file and how he need to be in the c file. In my .h : extern struct my_global_variable glob; and on my .c i add to reference it : struct my_global_variable glob; Is it like that ?? Thanks you for your answer and have
What is cflags’s function?
In this issue, CFLAGS set as path: https://unix.stackexchange.com/questions/149359/what-is-the-correct-syntax-to-add-cflags-and-ldflags-to-configure In this issue, CFLAGS set as compile option: How to use LDFLAGS in makefile I am confused. Answer CFLAGS stands for compiler flags. LDFLAGS is for linker flags. …
Why can a user-process invoke the Linux OOM-killer due to memory fragmentation, even though plenty of RAM is available?
I’ve got a headless ARM-based Linux (v3.10.53-1.1.1) system with no swap space enabled, and I occasionally see processes get killed by the OOM-killer even though there is plenty of RAM available. Running echo 1 > /proc/sys/vm/compact_memory periodically seems to keep the OOM-killer at bay, which make…
How to print IP address from Shell Script?
Below is my command line I want to get output of IP address(10.1.2.133) alone as output. How to write command line for that? Answer If you don’t mind a solution which is not elegant, but does the job, just pipe the output of your grep command into This splits the line first by the = and then :. If the
Deploying jar to unix server
Currently, in order to deploy my program to my ubuntu server, I have to do the following steps. 1. Compile the code using Gradle 2. Using FileZilla to move the jar to my server. 3. Connect to my server and find the process to kill it 4. restart the program. I am curious if there are any alternatives to this