If you use applications in English you don’t need translation for packages from English to English. If you stop this language related updates from apt-get, it will increase the apt-get update.
to do that open /etc/apt/apt.conf.d/00aptitude
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nano /etc/apt/apt.conf.d/00aptitude |
And add the following line at the end of this file:
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Acquire::Languages "none"; |
Did you ever need to search for a file that contains a specific text or string? use the command
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grep -r "my text to search" * |
Easy right? 🙂
changing port of your SSH server will make your server more secure, so to change the SSH port execute the code below
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nano /etc/ssh/sshd_config |
and edit Port number where you can see this line below. Press CTRL+X and save the changes when using nano to save the sshd_config file.
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# What ports, IPs and protocols we listen for Port 3999 |
Then restart the SSH server
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sudo service ssh restart |
These are the basic configuration for you to improve the security of your SSH server, these configuration are inside the /etc/ssh/sshd_config
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ServerKeyBits 2048 |
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Protocol 2 |
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ClientAliveInterval 300 |
ClientAliveCountMax 0
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IgnoreRhosts yes |
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HostbasedAuthentication no |
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PermitEmptyPasswords no |
Just restart your SSH server after doing changes by executing this command
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service ssh restart |
To change directory permission only on a certain directory
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find /www/html/htdocs -type d -exec chmod 755 {} + |
To change file permission only on a certain directory
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find /www/html/htdocs -type f -exec chmod 644 {} + |
Cannot login in SSH using root? you need to enable the root login in SSH!
Open the ssh configuration file using nano editor
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nano /etc/ssh/sshd_config |
Look for the configuration line that contains PermitRootLogin and change it into
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PermitRootLogin yes |
Run the following command to restart the SSH service
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sudo service ssh restart |
To get a specific PID of a certain process you want in ps aux you may use the command below
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ps aux | grep "[k]eyword" | awk '{print $2}' |
and for example usage we want to get the PID of a process running with chatserver/run-server.php
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ps aux | grep [c]hatserver/run-server.php | awk '{print $2}' |
and we will get this result
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7081 |
It is possible to login directly using root but its NOT RECOMMENDED, please proceed at your own risk!
Execute the following command in the terminal
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sudo passwd root |
To unlock the root account for login execute command
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sudo passwd -u root |
and it will display
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passwd: password expiry information changed |
To disable the root account login again run the following command
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sudo passwd -l root |
Do you want to login also in SSH using your root account? go to our tutorial here
Did you ever encountered that when you try to grep a ps aux result contains the grep process itself and you want to remove it so you can process the only grep result you want? You can put brackets on the keyword, study the pattern below
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ps aux | grep "[k]eyword" |
So when we run the ps aux | grep “run-server.php” as an example we will see the results includes the grep process
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dev-pin+ 7081 0.3 3.4 356208 34936 ? S 01:32 0:00 php chatserver/run-server.php root 7085 0.0 0.2 14116 2324 pts/0 S+ 01:33 0:00 grep --color=auto chatserver/run-server.php |
So to get the only the process we want we will enclose the first letter of our grep keyword with brackets like this
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ps aux | grep [c]hatserver/run-server.php |
By putting the brackets around the letter and quotes around the string you search for the regex, which says, “Find the character ‘c’ followed by hatserver/run-server.php
and we will get a result like this
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dev-pin+ 7081 0.0 3.4 356208 34940 ? S 01:32 0:00 php chatserver/run-server.php |
The standard SSH port number is 22 but what if the target linux machine you want to connect is running on different SSH port? you can do it by doing the command below;
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ssh -p3009 myusername@192.168.15.1 |
where 3009Â is the custom SSH port