In today’s internet this is quite normal sadly. There are hordes of botnets trying to login to each server they find in whole IP networks. Typically, they use simple dictionary attacks on well-known accounts (like root or certain applications accounts). The attack targets are not found via Google or DNS entries, but the attackers just … Read more
Meaning of the values The first line means: total: Your total (physical) RAM (excluding a small bit that the kernel permanently reserves for itself at startup); that’s why it shows ca. 11.7 GiB , and not 12 GiB, which you probably have. used: memory in use by the OS. free: memory not in use. shared … Read more
That depends on your distribution. On some system, it’s deleted only when booted, others have cronjobs running deleting items older than n hours. On Ubuntu 14: using tmpreaper which gets called by /etc/cron.daily, configured via /etc/default/rcS and /etc/tmpreaper.conf. (Credits to this answer). On Ubuntu 16: using tmpfiles.d. (Credits to this answer). On other Debian-like systems: … Read more
Do you mean tail -f logfile.log ? (Man page for tail)
I would choose a consistent approach across the entire environment. Both solutions work fine and will remain compatible with most applications. There is a difference in manageability, though. I go with the short name as the HOSTNAME setting, and set the FQDN as the first column in /etc/hosts for the server’s IP, followed by the … Read more
The mount command accepts –bind or -o bind. In the /etc/fstab file, you can use the following line: /source /destination none defaults,bind 0 0
To do this in a distro-independent* fashion you can use ldconfig with grep, like this: ldconfig -p | grep libjpeg If libjpeg is not installed, there will be no output. If it is installed, you will get a line for each version available. Replace libjpeg by any library you want, and you have a generic, … Read more
I have written a dns proxy in Python. It will read wildcard entries in /etc/hosts. See here: https://github.com/hubdotcom/marlon-tools/blob/master/tools/dnsproxy/dnsproxy.py
Deleting the filename doesn’t actually delete the file. Some other process is holding the file open, causing it to not be deleted; restart or kill that process to release the file. Use lsof +L1 to find out which process is using a deleted (unlinked) file.
I don’t think a command or shell builtin for this exists, as it’s a trivial subset of what the Bourne shell for loop is designed for and implementing a command like this yourself is therefore quite simple. Per JimB’s suggestion, use the Bash builtin for generating sequences: for i in {1..10}; do command; done For … Read more