CONTINUAL INTEGRATION

Goal:  You want to use unzip with Ubuntu Linux without using the GUI desktop.
Background:  The unzip character-based utility is useful for many reasons.  At the command line you can access compressed files that normally occupy little space on the disk.  Transferring .zip files is great for keeping network bandwidth utilization low.

Try this command to see if unzip is installed: man unzip

Part 1:  Installing Unzip
If the command cannot be found, use this command:  sudo apt-get install unzip

If the above command does not work, (for example, you do not have access to the Internet, and your network has no Debian package repositories configured), get the file from here:  https://packages.debian.org/wheezy/unzip

To find the correct installation media (and choose the correct link from the website above), you need to determine the architecture.  To do this, use this command: dpkg --print-architecture

Once you get the correct file on to Ubuntu, install it with this command: dpkg -i unzip.*.deb

Part 2:  Using Unzip
Now that unzip is installed, you can use it with a command like this (assuming you have a file named foobar.zip):

unzip foobar.zip

The above command will decompress the contents while retaining a copy.  The extracted contents will be decompressed in the same directory you run the command in.  The extracted files will not go to the directory where foobar.zip is if you use the path of foobar.zip in the invocation of the unzip command (e.g., if you are in /root/ and run unzip /tmp/foobar.zip the extracted files will go into the /root/ directory).

Goal:  You want to use zip with Ubuntu Linux without using the GUI.  You want to use the character prompt exclusively.

Background:  The zip character-based utility is useful for many reasons.  At the command line you can free up space while retaining files for future usage.  Try this command to see if zip is installed: man zip

Try this command to see if zip is installed: man zip

Part 1: Installing Zip
If the command cannot be found, use this command:

sudo apt-get install zip

If you do not have access to the Internet, and your network has no Debian package repositories configured, get the file from here:  https://packages.debian.org/wheezy/zip

To find the correct installation media (and choose the correct link from the website above), you need to determine the architecture.  To do this, use this command: dpkg --print-architecture

Once you get the file over, install it with this command: dpkg -i zip.*.deb

Part 2  How to Use Zip
Now that zip is installed, you can use it with a command like this (assuming you have three regular files named pub.txt, pub1.txt, pub2.txt):

zip target.zip pub.txt pub1.txt pub2.txt

The above command will create a zip file called target.zip.  The files will be compressed (that is, the .zip file will be smaller than the sum of the three .txt files' sizes).  This can help reduce disk I/O when fetching the file, moving it around, and reduce network congestion with fewer packets over the network when it is in transit.

Goal  You want to use unzip when you are using SUSE (either openSUSE or SUSE Linux Enterprise).

Background
The unzip character-based utility is useful for many reasons.  At the command line you can access compressed files that normally occupy little space on the disk.  Transferring .zip files is great for keeping network bandwidth utilization low.

Try this command to see if unzip is installed: unzip --version
AWS SUSE servers have unzip installed by default, but they have no man pages.

Part 1:  Installing Unzip
If the command cannot be found, use these commands:

sudo su -
zypper install unzip

If the above command does not work, (for example, you do not have access to the Internet, and your network has no Debian package repositories configured), go here to get a file:

http://software.opensuse.org/download.html?project=Archiving&package=unzip

To find the correct installation media (and choose the correct link from the website above), you need to determine the architecture.  To do this, use this command: cat /etc/*-release

The above command will tell you if you are using SUSE Linux Enterprise or openSUSE.  The buttons can be right clicked to copy the location (e.g., to use wget http://software.opensuse.org/ymp/Archiving/SLE_12_SP1/zip.ymp).  Otherwise you click "Grab binary packages directly" and then download the appropriate file to your workstation and transfer it over to the Linux machine (e.g., with SFTP or SCP).

Once you get the file over, install it with this command: zypper install /path/to/unzip.rpm

Part 2:  How to Use Unzip
Now that unzip is installed, you can use it with a command like this (assuming you have a file named foobar.zip):

unzip foobar.zip

The above command will decompress the contents while retaining a copy.  The extracted contents will be decompressed in the same directory you run the command in.  The files will not necessarily go to the directory where foobar.zip is (e.g., if you are in /root/ and run unzip /tmp/foobar.zip the extracted files will go into the /root/ directory).

Goal:  You want to use zip when you are using SUSE (openSUSE or SUSE Linux Enterprise).  You want to use the character (or command) prompt.  You do not want to use the GUI.
Background:  The zip character-based utility is useful for many reasons.  At the command line you can free up space while retaining files for future usage.  Try this command to see if zip is installed: man zip

Part 1 Installation Process
If the command cannot be found, use these commands:

sudo su -
zypper install -y zip

If you do not have access to the Internet (so a .ymp file could not help you), and your network has no .rpm package repositories configured, get the file from here:

http://software.opensuse.org/download.html?project=Archiving&package=zip

If you are using a free SUSE Linux with AWS, then your version is SLE (not openSUSE).  To find the exact version of SUSE you are using, issue this command: cat /etc/*-release
AWS SUSE servers have zip installed by default.

The buttons can be right clicked to copy the location (e.g., to use wget http://software.opensuse.org/ymp/Archiving/SLE_12_SP1/zip.ymp).  But .ymp files are only useful if your server has Internet access.  You click "Grab binary packages directly" and then download the appropriate file to your workstation and transfer it over to the Linux machine (e.g., with SFTP or SCP).    

Once you get the file over, install it with this command: zypper install /path/to/zip*rpm

Part 2  How to Use Zip

Now that zip is installed, you can use it with a command like this (assuming you have three regular files named pub.txt, pub1.txt, pub2.txt):

zip target.zip pub.txt pub1.txt pub2.txt

The above command will create a zip file called target.zip.  The files will be compressed (that is, the .zip file will be smaller than the sum of the three .txt files).  This can help reduce disk I/O when fetching the file, moving it around, and reduce network congestion with fewer packets over the network when it is in transit.

How do you unzip files using Red Hat Enterprise Linux (or CentOS or Fedora Linux)?

Goal:  You want to use unzip when you are using Red Hat Enterprise Linux (or CentOS or Fedora Linux).
Background:  The unzip character-based utility is useful for many reasons.  At the command line you can access compressed files that normally occupy little space on the disk.  Transferring .zip files is great for keeping network bandwidth utilization low.

Try this command to see if zip is installed: man zip

Try this command to see if unzip is installed: man unzip

Part 1:  How to Install Unzip
If the command cannot be found, use these commands:

sudo su -
yum install -y unzip

If you cannot install unzip that way (either because you have no Internet connection or rpm package repository server configured on your network), go to this URL:  http://rpmfind.net

Search for "unzip."  To determine the exact version of RedHat Linux you are using, issue this command: cat /etc/*-release

While rpmfind.net has no RHEL packages, CentOS rpms should work. They definitely work for RHEL 7.2 for unzip.  

Once the .rpm is downloaded, you can use this command: rpm -ivh unzip-6.0-15.el7.x86_64.rpm

(where unzip-6.0-15.el7.x86_64.rpm is the exact name of the rpm package you downloaded)

Part 2: How to Use Unzip

Now that unzip is installed, you can use it with a command like this (assuming you have a file named foobar.zip):

unzip foobar.zip

The above command will decompress the contents while retaining a copy.  The extracted contents will be decompressed in the same directory you run the command in.  The files will not necessarily go to the directory where foobar.zip is (e.g., if you are in /root/ and run unzip /tmp/foobar.zip the extracted files will go into the /root/ directory).

Goal:  You want to use zip when you are using Red Hat Enterprise Linux (or CentOS or Fedora Linux).
Background:  The zip character-based utility is useful for many reasons.  At the command line you can free up space while retaining files for future usage.  Try this command to see if zip is installed: man zip

Part 1:  How to install zip?
If the command cannot be found, use these commands:

sudo yum install -y zip

If you do not have access to the Internet, and your network has no rpm  configured, get the file from here:  http://rpmfind.net

Search for "zip."  To find the exact version of RedHat you are using, issue this command: cat /etc/*-release

While rpmfind.net has no RHEL packages, CentOS rpms should work. They definitely work with RHEL 7.2 for zip.  

Once the .rpm is downloaded, you can use this command: sudo rpm -ivh zip-3.0-10.el7.x86_64.rpm

(where zip-3.0-10.el7.x86_64.rpm is the exact name of the rpm package you downloaded)

Part 2:  How to Use Zip
Now that zip is installed, you can use it with a command like this (assuming you have three regular files named pub.txt, pub1.txt, pub2.txt):

zip target.zip pub.txt pub1.txt pub2.txt

The above command will create a zip file called target.zip.  The files will be compressed (that is, the .zip file will be smaller than the sum of the three .txt files).  This can help reduce disk I/O when fetching the file, moving it around, and reduce network congestion with fewer packets over the network when it is in transit.

Goal:  You want to issue a command (e.g., an export command) that has a password in it.  But you do not want anyone looking over your shoulder to see it.  You do not want the password to be visible in the history of the shell.
Solution:  Type this 'read -s foobar'
Then press enter.  The cursor will go to the next line.  Type in the password.  The characters will not echo to the screen.  The cursor will not advance.  Press enter.  Now you can use the variable like this: $foobar
For example, you can use export special_setting=connectionString@format:jdoe:$foobar
You will now have exported a setting that will be interpret "$foobar" as the password you entered.  The content of the variable will never be displayed.  It is important to remember that the variable name in the first "read -s foobar" statement has no dollar sign "$".  While the variable's reference, for evaluation, uses a dollar sign "$".  This is a convention in bash scripts as well as interactive bash commands.