Linux Move (mv) Command

The Linux move command (mv) is one of the essential commands, which can be very useful in Linux, Unix, and AIX.  The primary purpose of the move command is obviously to move files, and of course, directories.   The move command may also be used to rename files and to make backups.

Move Command Syntax

$ mv [options] source (file or directory)  destination

Move Command options

option description
mv -f force move by overwriting destination file without prompt
mv -i interactive prompt before overwriting
mv -u update – move when the source is newer than the destination
mv -v verbose – print source and destination files
MV – t explicitly saying to move the file or directory here, rather trying to fit everything into the last argument.
mv * Move all (Multiple) files to a specific director without listing by name

For More move command details see the Linux documentation manuals using the man command

$ man mv

mv command examples

Here are some quick and very simple move command (MV) examples for reference.

Move Move to files  to the /Archive/ directory:

$ mv happy.txt garden.txt /Archive/

Move all “.txt” files in the current directory to subdirectory backup:

$ mv *.txt backup

Move all files in subdirectory ‘backup’ to current directory:

$ mv backup/*

Rename file happy.txt to happy.bak filename:

$ mv happy.txt happy.bak

Rename directory backup to backup2:

$ mv backup backup2

Update – move when happy.txt is newer or missing in target directory:

$ mv -u happy.txt backup

Move happy.txt and prompt before overwrite backup / happy.txt:

$ mv -v happy.txt backup

Use and Advantages of Apache Derby DB


Developed by Apache Software Foundation, Apache Derby DB is a completely free, open-source relational database system developed purely with Java. It has multiple advantages that make it a popular choice for Java applications requiring small to medium-sized databases.

Reliable and Secure

With over 15 years in development, Derby DB had time to grow, add new and improve on the existing components. Even though it has an extremely small footprint – only 3.5MB of all JAR files – Derby is a full-featured ANSI SQL database, supporting all the latest SQL standards, transactions, and security factors.

The small footprint adds to its versatility and portability – Derby can easily be embedded into Java applications with almost no performance impact. It’s extremely easy to install and configure, requiring almost no administration afterward. Once implemented, there is no need to further modify or set up the database at the end user’s computer. Alongside the embedded framework, Derby can also be used in a more familiar server mode.

All documentation containing different manuals for specific versions of Derby can be found on their official website, at :

Cross-Platform Support

Java is compatible with almost all the different platforms, including Windows, Linux, and MacOS. Since Derby DB is implemented completely in Java, it can be easily transferred without the need for different distribution downloads. It can use all types of Java Virtual Machines as long as they’re properly certified. Apache’s Derby includes the Derby code without any modification to the elemental source code.

Derby supports transactions, which are executed for quick and secure data retrieval from the database as well as referential integrity. Even though the stored procedures are made in Java, in the client/server mode Derby can bind to PHP, Python and Perl programming languages. 

All data is encrypted, with support for database triggers to maintain the integrity of the information. Alongside that, custom made functions can be created with any Java library so the users can manipulate the data however they want. 

Embedded and Server Modes

Derby’s embedded mode is usually recommended as a beginner-friendly option. The main differences are in who manages the database along with how it’s stored. 

When Derby is integrated as a whole and becomes a part of the main program, it acts as a persistent data store and the database is managed through the application. It also runs within the Java Virtual Machine of the application. In this mode, no other user is able to access the database – only the app that it is integrated into. As a result of these limits, the embedded mode is most useful for single-user apps.

If it’s run in server mode, the user starts a Derby network server which is tasked with responding to database requests. Derby runs in a Java Virtual Machine that hosts the server. The database is loaded onto the server, waiting for client applications to connect to it. This is the most typical architecture used by most of the other bigger databases, such as MySQL. Server mode is highly beneficial when more than one user needs to have access to the database across the network.

Downloading Derby

Derby has to be downloaded and extracted from the .zip package before being used. Downloads can be found at the Apache’s official website:

Numerous download options are presented on there, depending on the Java version that the package is going to be used with. 

Using Derby requires having Java Development Kit (JDK) pre-installed on the system and then configuring the environment to use the JDBC driver. Official tutorials can be found at:

Running and Manipulating Derby DB

Interacting with Derby is done through the use of ‘ij’ tool, which is an interactive JDBC scripting program. It can be used for running interactive queries and scripts against a Derby database. The ij tool is run through the command shell.

The initial Derby connection command differs depending on whether it’s going to be run in embedded or server mode.

For a tutorial on how to use the connect commands, check out https://www.vogella.com/tutorials/ApacheDerby/article.html.

Some Useful Derby DB Documentation

Derby Reference Manual‎: ‎

Derby Server and Administration Guide‎: ‎

API Reference‎:

Derby Tools and Utilities Guide‎: ‎

ij Basics

In conclusion, Derby DB is a lightweight yet efficient tool that can be integrated into various types of Java applications with ease.

Useful Links – Linux

Here are a few useful references for Linux, which may be helpful.

Linux Documentation

Bash Documentation

Links for Major Linux Distributions

CentOS

Red Hat Enterprise Linux (RHEL)

Ubuntu

The most Important Linux Distributions To Learn Professionally

Many of us either want a way to import our Linux knowledge, improve our technical career options or perhaps, move into the technology career.  To do any of these efficiently them, the first step would be to focus on the major Linux distribution used by employers. 

The most adapted distributions Linux are Red Hat Enterprise Linux (RHEL) and Ubuntu, so, of the multitude of Linux distributions available, these would be the to learn if you want to move your career forward.

However, if you are seeking an inexpensive alternative to hone your Linux skills at home, then CentOS, is likely your best choice since it is free and is pretty much a copy of RedHat.

Related References

8 Most Useful Linux Commands For Beginners

Do you think that the command lines are an old-fashion leftover from previous decades or an antiquated way of using a PC? Think again. Indeed, it is one of the most powerful and flexible ways to perform and manage in Linux. If you come from the comfort of a Mac or Window desktop, however, it can be a bit intimidating to get used to Linux commands. Everything is secretive, dark, and anything but friendly to beginners. That’s why we have rounded up this short list of the most useful Linux commands with examples. Keep reading and speed up your learning journey with Linux.

1. Ls command – list files

Ls is one of the most basic and common commands in Linux. You can use it to print contents in the current working directory and see the list of files, directories, or folders on your Linux system.
For instance, the command “ls tourism” will display the users every folder store inside the overall “tourism” folder. Keep in mind that directories and files will be denoted in different colors, which can be selected in the system.
You would also use the command “ls – R” to display all files both in the directories and subdirectories. Since Linux commands are case sensitive, make sure to enter “R” instead of “r” to avoid an error.

2. Cat command – create and view files

You can use the “cat” command to show text files. Also, it would be used for creating, combining, and copying text files. For example, use “cat linux_tip” to get inside the linux_tip file and read its contents on the screen.
To combine two text files “linux_tip_1” and “linux_tip_2, you can enter the following command “cat linux_tip_1 linux_tip_2 > linux_tip”. Keep in mind that only text documents would be combined and shown with this command.

3. Rm command – delete files

The “Rm” command can be used for removing files or directories from your Linux system without confirmation. The syntax is simple “Rm name_deleted_file.”
For example, the command “rm computer_science” will immediately remove the file or directory named “computer_science” from your computer. Make sure to consider carefully before using this command because you cannot get it back.

4. mv command – move and rename files

To move and rename files, the “mv” command will be used. Here is the basic syntax for this task: “mv filename new_location.”
Suppose that you need to move the file name “english_class” to location “/home/school/documents”, just enter the command “mv english_class /home/school/documents.” Keep in mind that this command requires the permission of users.
The syntax for renaming a file is “mv filename newname”. An example command is “mv english_class french_class”

5. Mkdir – create directories

If you want to create a new directory in your Linux system, then you can use the “mkdir” command. The syntax is “mkdir new_directory.”
For instance, you can create a new directory named “final homework” by typing the following command “mkdir final_homework.” In case you do not want to make a parent directory manually, add the -p argument. Keep in mind that it is -p, not -P. Everything in Linux is case sensitive.

6. Rmdir command – remove directories

In contrast with the mkdir command, you can use the rmdir command to remove a directory. The syntax is similar: “rmdir removed_directory.”
If you enter the following command “rmdir basketball_data”, it will immediately delete the directory named “basketball_data”. Always check carefully to make sure that there is no sub-directory or file under the deleted directory. If possible, it is always better to delete the sub-directory or files first before moving to the parent one.

7. Man command – seek help in Linux

“Man” simply stands for manual. You can use this command to access a reference book of the Linux system, which is quite similar to the “Help” file in many popular applications or software. To seek help on any commands that you don’t understand, just enter “ma command_name”. The terminal will open a manual page for the typed command.
For example, if you enter “man ls”, the terminal will provide you with basic information on the “ls” command.

8. History command – view previous commands

As you can guess from the name, the “history” command can be used to display all of the commands that you just used previously for the current session. This can be helpful in referring to the old commands and re-entering or re-using them in the next operations.

Related References

Linux – What is yum?

Linux
Linux

In simple terms, yum is a, command-line interface, package manager utility for computers running the Linux operating system, which augments the RPM Package Manager capabilities. yum is the primary tool for getting, installing, deleting, querying, and managing RPM software packages. Also, yum is used in Red Hat Enterprise Linux (RHEL) versions 5 and later.

Linux – how to display file system disk space statistics

Linux
Linux

In Linux there are lot of ways to disk size and/or space, but the ‘Disk Filesystem’ (df) command is old reliable and has been around a long time.   The ‘df’ command provides a summary of disk space and free space, which I find myself coming back to time after time.

Basic Command Format

DF -<<Option>>   <<File>>

Example ‘Disk Filesystem’, Command

df -h

  • -h = Human readable in MegaBytes

For more details in Linux

df –help

Example Command Output

root@BlogSrvr1 /]# df -h

Filesystem            Size  Used Avail Use% Mounted on

/dev/mapper/vg_BlogSrvr1-lv_root

36G   34G   16M 100% /

tmpfs                 3.9G     0  3.9G   0% /dev/shm

/dev/sda1             477M   33M  419M   8% /boot

/dev/mapper/vg_BlogSrvr1-LogVol03

11G   27M  9.9G   1% /data

/dev/mapper/vg_BloSrvr1-lv_home

4.8G   33M  4.6G   1% /home

/dev/mapper/vg_BlogSrvr1-LogVol04

25G   13G   11G  55% /opt/IBM

/dev/mapper/vg_BlogSrvr1-LogVol05

11G  6.0G  3.7G  62% /scratch

/dev/mapper/vg_BlogSrvr1-LogVol06

11G   27M  9.9G   1% /tmp/dev/shm