How to Fix Error Makefile: *** Missing Separator?
The whitespaces in the Makefile cause this error, which is fixed using the vim editor’s syntax features that filter the whitespaces and tabbed spaces.
The whitespaces in the Makefile cause this error, which is fixed using the vim editor’s syntax features that filter the whitespaces and tabbed spaces.
To uninstall packages with apt package manager in Debian-based distributions, we can use the apt remove, apt autoremove, and apt purge commands.
The most widely used command line methods to list disk details and mounted file systems in Linux are lsblk, df, cfdisk, lshw, fdisk, hwinfo, and sfdisk.
We can temporarily set the SELinux permissive mode with the “sudo enforce 0” command and permanently with “SELINUX=permissive” in the /etc/selinux/config file.
In Linux, vim plugins can be installed easily using the vim plugin manager or manually adding plugins to vim, as explained with practical plugin installations.
To set up Outlook on Linux, install an email client named Prospect-Mail and then use your Outlook credentials to sign in through the Prospect-Mail.
The xxd command can convert text into hexadecimal text, binary and reverse the hexadecimal to normal text as explained in this guide with different examples.
The important uses of the tcpdump command are explained, which can be very helpful for beginners to monitor the network communication with the tcpdump command.
The XFS file system should be used if the file sizes are large, while the ext4 is more beneficial when the I/O workload is greater or CPU resources are less.
This guide explains the functionalities, strengths, and weaknesses of the Linux Operating system’s Btrfs and Ext4 file systems.
The “too many connections” error can be fixed by increasing the MySQL connections limit directly from the MySQL server or the MySQL configuration file.
The nginx 504 gate time-out error can be resolved by increasing the proxy, and FastCGI connect, read and send times to more than default time-out of the Nginx.
The best network scanners in Linux are Nmap, Angry IP Scanner, Fping, Nessus, OpenVAS, and Arp Scan, whose details and installation methods are explained.
There are two methods to add the users to sudoers in Linux: adding the user to the sudo group or adding to the default sudo /etc/sudoers file.
GNU Debugger (GDB) acts as a compiler for various languages, i.e., C, and C++. Read out this post to get the list of GDB commands and their usage with examples.
The nmap provides advanced features to scan for vulnerabilities in a specific port, multiple ports, and the range of a port, as shown in the article.
The wildcards to find the specific filename, the file starting or ending with a specific character, number, or extension, as explained in this guide.
Linux’s sysbench is a benchmark tool that tests CPU, I/O, memory, and database performance at default and given conditions, as explained in this article.
We can list GPG keys in Linux that help the users to view the information of public keys, secret keys, signatures, and fingerprints of the GPG keys.
The ufw service can be allowed on SSH for a specific IP address, subnet, port number, and connection, as done in this article.
Several methods are discussed to write to a file in bash, which helps to write single or multiple lines and the same content to multiple files simultaneously.
To create a user with a different home directory in Linux, we can use the “d” option of the useradd command as performed in this article.
Command-line arguments are parameters passed to a script while executing them in the bash shell, and their uses are discussed in detail throughout this article.
We can use the Bash heredoc method in Linux to execute multiple lines of commands and data simultaneously, which is explained in this guide with examples.
The OpenSSL S_Client command can be used to test, debug, disable the client-side connection and print, check, verify, and specify cipher for SSL certificates.
Several methods are used to write comments in Linux bash scripts, such as single-line, inline, and multi-line comments, as described in this tutorial.
Multiple methods are used to do a port scan in Linux, which are nmap, netcat, ss, netstat, lsof, and telnet commands. All these are practically demonstrated here.
Several methods to detach a session in Tmux are explained in this guide with the help of examples that include shortcut, command, and GUI methods.
To list Tmux sessions “tmux ls”, “tmux list-sessions” and to attach “tmux attach-session -t
The DNS converts the domain name to a universally readable ip address, and to search the DNS history in Linux, use the “dig”. “Host” and “nslookup” commands.
All the Tmux sessions in Linux can be killed by using the “pkill -f tmux”, “tmux kill-server”, and “tmux kill-session -a” commands and using the system monitor.
The SSH port forwarding tunnels one server traffic to another on a specific port in Linux that is done using the “L” option with the SSH command.
The SSH default port is changed due to security reasons, and to change it, edit the ssh configuration file “/etc/ssh/sshd_config” or run the “sed” command.
The swap memory is the secondary memory for the RAM used when the system RAM is full. The types, advantages, checking, and creating the swap are discussed.
To format a drive or partition in Linux, we can use the fdisk, gdisk, mkfs command-line methods, while the GNOME Disks GUI method can also be used.
We can find the UUID of the storage devices in Linux using the “blkid”, “lsblk”, “/dev/disk/by-uuid” and “/etc/fstab” methods as discussed in this article.
The SSL certificate errors in Linux can be ignored or hidden by using the “-k” or “–ignore” options with the curl command or updating the CA certificates.
In Linux, the Nmap scans for online hosts using specific communication protocols, port numbers, live hosts, and IP addresses within a network.
The SUID permissions are same as the user (owner), GUID is similar to the group, and with sticky bits can delete directories for yourself only, not for others.
The bash exit command quits the terminal or script and shows a specific exit code based on the command execution that can be used for conditional exiting.
SSH too many authentication failure errors can be fixed using the correct SSH key, increasing the MaxAuth limit, and using authentication identity keys only.
The tls/ssl error occurs if the required libraries are missing which can be removed by installing the “glib-networking” package or updating the ca-certificates.
The dry-run rsync command in Linux is used to test the output without any changes in the system to sync data between local and remote servers using its options.
We can create, remove, copy, move, read, write, and edit a file having a filename with spaces in Linux, using the “quotes” or “backslash” within the filenames.
To add a directory to PATH in Linux, add the specified directory path to its Shell configuration file such as “bashrc” for the bash and “zshrc” for z shells.
Three methods are used to append the data to the bash file in Linux, which are the redirect operator (>>), cat, and tee commands, as discussed in this guide.
We can redirect the standard output (stdout) and standard error (stderr) to separate files or stderr and stdout to a similar bash file.
Learn how to use the bash while loop to execute a set of commands repeatedly until a specified condition is met. It can help you automate your tasks.
Bash arrays are used to store several types of data information, which can be used to perform desired operations in Linux, as discussed in this article.
This error occurs when the root user account is not set up correctly. To fix the error, set the root user password for MySQL and log in again.
The bash printf command in Linux prints the output with specific formatting using backslash-escaped characters, conversion or format, and width specifiers.
Bash functions in Linux are used with local & global variables. Arguments can be passed, or user input can be taken to make the functions interactive.
The update-grub command not found error can be resolved by running the “grub-mkconfig” command or adding the grub-mkconfig $Path to the grub default file.
Latest version of PHP can be installed using the “$ sudo apt install php8.2” and “$ sudo apt install php8.2-cli” commands.
To install MySQL on Ubuntu 22.04, use the “sudo apt install mysql-server -y” command and configure using the “$ mysql_secure_installation” command.
In Linux, to move a file to another directory, the “mv” command is used, or choose the “Move to…” option after selecting the file from GUI as discussed.
To find the process id, use the commands “pidof”, “pgrep”, “pstree”, or “ps aux”. And to kill it, use the “killall
The xargs command converts the previous command arguments to xargs input that performs several tasks like showing file content, creating and replacing files.
To fix the “too many open files” error in Linux, increase the opened files limit for the current session or for permanent.
The sleep command adds the delay time in the bash script, which runs after specific time intervals such as seconds (s), minutes (m), hours (h), and days (d).
In Linux, three different operators, +, ++, and += are used to increment, and -, –, and -= are utilized to decrement a variable using the bash script.
The bash aliases are created by adding the alias into the ~/.bashrc file or creating a separate aliases file and adding its reference to the ~/.bashrc file.
To concatenate bash strings, you can use strings together ($Str1$Str2), use curly braces (${Str1}${Str2}), and use the += operator (Str1+=”$Str2”).
Comparison operators like the equality (= or ==), the not equality (!=), an empty string (z), and a non-empty string (n) are used to compare strings in bash.
The wait command in the Linux bash scripts waits for the previous commands to complete execution for a specific PID, for the first PID only, and all the PIDs.
The read command reads the standard input and executes the commands with arguments as a prompt, reads array values, and sets the characters & time limit.
The Bash case statement checks the multiple input values against the set cases. It executes the correct statement and quits the case statement.
The SSH could not resolve hostname error can be fixed by using the correct hostname & ip address or adding a manual SSH entry in the “/etc/hosts” file.
In Linux, the User ID (UID) stores all the user’s information which can be used with different commands like id, cat, getent, and awk to find users information.
We can find & replace with the substitute command or find the word with forward slash “/” and replace with dot sign “.”. Read this post for further details.