I’m trying to implement named PIPE based inter-process communication between a running java program and console. Contents of java program (Test.java) are: Program was compiled using: A named pipe was created: Then program was ran as consumer of pipe STDOUT: Then, using console, I’m sending a ping …
Tag: linux
Conditional append of strings on fields in a csv file
I am trying to convert a csv file like below with bash scripts. Headers and structures are always the same. Source csv file: Conditional values (will change depending on the requirements) Now I am trying to get the following result without the first row and values are now separated by spaces if each header ma…
`gulp` command doesn’t work as expected on Linux
I am trying to set up the needed environment for a project I am gonna work on. I am not able to run gulp command as expected (as it is told on the getting started page of Gulp). I am using Linux (PopOS) which is based on Ubuntu and Debian. So, I have tried to fix it in the local
How to “catch” non-zero exit-code despite “set -e” then echo error code
I have script purpose of script is to terminate execution on any non zero command exit code with set -e except when command is “caught” (comming from Java) as in case of bad command asd however, though I “catch” the error and end of script prints to terminal, the error code is 0 so my …
How to print full trace file of trace_printk in ftrace?
I am using trace_printk() to print some numbers (they are around a million number). However when I check /sys/kernel/debug/tracing/trace … only a part of the full range is printed. Can anyone suggest me how to increase the buffer size or any way to print the full range via any option. *Note: I don’…
Write background command output (stdout) to file during execution
I have a command that takes a long time that I like to run in the background like this: This works perfectly in the sense that the command is indeed in the background and I can check the output and potential errors later. The main problem is the output is only appended after the command is completely finished…
how to use mmap and shm_open to shared memory among multiple independent processes
I want to share memory among processes, which run independently instead of fork. I’ve read the man page for mmap and shm_open, and still confused about the usage. shared memory, in my mind, should be the mechanism of mapping virtual memory space among different processes, but Why mmap has the fd argumen…
How can I automate the user creation in Linux servers using Python
Well I’m trying to create a script to automate the user creation in Linux servers, so I generated the ssh keys in each server and made a code like this: But, I’m getting the error: When I remove ssh myuser@lab part, the script work in the localhost. Could someone help me with this issue? Answer Yo…
recursively find directories without setgid set
In linux, how do you recursively pull up a list of all directories that do NOT have the setgid bit set? I know you can do to find all the directories that have it set, but it’s not obvious to me how to negate this. Or if another tool is more appropriate for this use case. I’ve got a rather
Find Most Recent File in a Directory That Matches Certain File Size
I need to find the most recently modified file in a directory that matches 3.0 MB. First Attempt Second Attempt Am I close? Answer This should work: ls -lh –sort=time /path/to/directory/*.file | grep “3.0M” | head -n =1