Let’s say I have 3 linux servers. I need a script that will login from s1 to s2 via ssh, then from s2 to s3 via ssh, then check, if there is already exists string in ~/.ssh/authorized_keys from s1 then do nothing otherwise do s1 and s2 are constant, s3 can be variable. ssh from s1 to s2 already settled
Tag: linux
How to replace newlines between brackets
I have log file similar to this format Here is the echo command to produce that output $ echo -e “test {nseq-cont {nttt0,nttt67,nttt266nttt},nttgrp-id 505nt}n}ntest{nttest1{nttvalnt}n}n” Question is how to remove all whitespace between seq-cont { and the next } that may be multiple in the file. I want the output to be like this. Preferably use sed to produce the output.
Do you know how to make the system automatically restart daemon service?
I have made a daemon service in linux server. It is running well. The service file is stargate.service (in /etc/systemd/system). If by some reasons, the daemon service is die and stop. Do you know how to make the system automatically restart the daemon service ? How to make the daemon service starts if server get rebooted? Answer To respawn your
Root privileges needed for “systemctl suspend” command
On an embedded Linux device (Colibri module with an iMX7d processor) I am not able to run the command systemctl suspend as an non-root user in order to switch into suspend mode. When I log in as root user, the command is executed and the system switches to suspend mode. The same command runs on a Ubuntu PC system as
phpspreadsheets/ phpoffice not working on linux
I have downloaded composer successfully and I am trying to use the phpospreadsheet library but I keep getting these errors although this is a basic code. it works on windows but not on linux. Code Sample: Errors: Answer the solution was to make a temporary directory. https://github.com/PHPOffice/PhpSpreadsheet/issues/1123
run a command with a file pattern
I have this file patterns.txt And I want to run a specific command for every pattern like this: I tried to used for loop like this: but i didn’t work Answer The 2 typical approaches are: and Note that I would expect both of those to fail, since scp expects at least 2 arguments. How you want that 2nd argument
Restart Opencanary from Crontab
I have a programm called opencanary running at a virtual environment at my Raspberry Pi with Ubuntu 18.04 installed. I want to restart it every 30 Minutes using crontab. For testing I set the script to run every 3 Minutes as you can see below. When I execute the script manually it’s working fine. When using crontab to run it
Protecting against Time-of-check to time-of-use?
I was reading: https://en.wikipedia.org/wiki/Time-of-check_to_time-of-use They showed this code to be buggy and I totally understand why it’s so: But the real question is how to protect against this type of exploits? Answer You can use the O_NOFOLLOW flag. It will cause the open to fail if basename of the path is a symbolic link. That would solve the described attack.
Filtering on a condition using the column names and not numbers
I am trying to filter a text file with columns based on two conditions. Due to the size of the file, I cannot use the column numbers (as there are thousands and are unnumbered) but need to use the column names. I have searched and tried to come up with multiple ways to do this but nothing is returned to
Cannot compile Makefile using make command on Windows
Problem summary I am trying to install an open-source parallel finite-element code called TACS and available at this github repository. To comply with the indicated prerequisites, I followed the instructions at this github repository, which allowed me to install SuiteSparse and METIS on Windows with precompiled BLAS/LAPACK DLLs. For the MPI, I installed both the Intel MPI Library and Open