Tips & Tricks for Testing and Managing Web Applications Run by Linux OS

Guidelines for Inspection, Maintenance, and Adjusting Web Applications Executed on Linux:

We’ll investigate the strategies to maneuver the increasingly adopted Linux operating system to examine web applications. This guidance is relevant to any Unix-style variant if your application is hosted on servers running on Linux.

This guide will be useful for beginners studying Linux. We have spoken about some frequent queries that often occur during the learning phase.

We will delve into several vital subjects that QA Engineers are prone to encounter while handling and testing web applications on Linux OS.

Recommended study: UNIX fundamentals for Software Checkers.

Let’s commence with a concise history. Linux buffs made remarkable efforts to introduce the benefits of Unix-style OSes to the IT crowd. Due to their commitment, Linux has amassed enormous acceptance nowadays.

Data reveal that majority of supercomputers and heavily taxed application servers operate on Linux. Linux servers are recognized for steadiness and competence, making them perfect for supervising a large volume of users (e.g., social networks).

Now, let’s juxtapose Windows and Linux:

Windows vs Linux

1. Linux has a core advantage: it is complimentary and established on open-source software. An abundance of distributions already incorporate a multitude of software and drivers at zero expense.
2. Support, defect corrections, and novel elements for Linux are provided by the proactive Unix fellowship globally, contrasting Windows which gets its main support only from Microsoft.
3. Linux proposes exceptional suppleness, empowering users to modify and adjust according to their inclinations. Meanwhile, Windows imposes limits on customization.
4. Linux is appreciated for its sturdy security and solidity, making it less susceptible to viruses and malware compared to Windows.
5. Linux produces high execution, making it the preferred pick for web and telecom patrons. More than 95% of supercomputers execute on Linux.

These are merely a few advantages of Linux. Let’s press forward in our exploration.

Initially, let’s bestow some tips to maneuver Linux nuances.

Useful Tips for Linux Testing:

General *nix Must-Knows

Here are some elemental points to get you initiated:

• The man command is the finest tool for amateur Linux users. It exhibits the online manual pages for a specified command. For example, man ls will provide details about the command: Name, Synopsis, Description, Options.
• Command designations, paths, and file identifiers are case-sensitive. As an instance, “test.log” and “TEST.log” could refer to different files in the same directory.
• Utilizing spaces in file denominations within the terminal could provoke problems due to spaces being utilized as dividers for multiple command arguments. Employ underscores or CamelCase as an alternative. For instance, use “test_log” or “testLog” instead of “test log”.
• To rename a file using the mv command, utilize mv test.tar.gz temptest.tar.gz. This will alter the name of “test.tar.gz” to “temptest.tar.gz”.
• There isn’t an “undo” option in Linux. Once a file is overwritten or modified, it cannot be returned to its original state.
• Linux does not have a “Trash” or “Recycle Bin” feature. Erased files cannot be effortlessly revived using basic tools in most Unix forms. Be careful when erasing files and stipulate distinct parameters for the rm command. For example, use rm -I test*.txt to prompt for agreement before erasing files. You can also devise an alias to modify the behavior of the rm command if data loss is a nagging issue.
• Be vigilant when making use of shortcuts like the current directory (.) and parent directory (..). Avoid running commands like rm -r .* to avoid unwittingly erasing the parent directory.
• Make good use of the autocomplete feature in the console, which lets you swiftly input command or file designations by typing some characters and pressing Tab.
• You can refer to past command history utilizing the up and down arrow keys on your console.

Name And Path Limitations In Linux OS

Let’s now argue about path types and limitations in the Unix-style OS.

To start with, let’s clarify some common terms:

An absolute path denotes the file or directory location from the root directory (top level). For instance, /var/log/protocol/log.

A relative path refers to a path regarding the current directory (pwd). For example, if you’re in the /var/log directory and desire to navigate to /var/log/protocol/log/, you can utilize a relative path like cd protocol/log/.

There are restrictions on folder and file denominations in Unix-like systems (these limitations should also be contemplated when examining web applications):
– Maximum 256 characters for a name
– Maximum 1024 characters for an absolute path.

It is generally not advisable to log in as the root user (i.e., the top-level user or Administrator). Even so, numerous administrative tasks necessitate root privileges, like starting/stopping web apps, restarting/cleaning databases, or launching new builds.

The alternative is to use the sudo command, which confers temporary administrator permissions. As an example, utilize sudo apt-get install shell utilities.

Job And Process Management In Linux

Handling jobs and processes is a fundamental aspect of Linux administration on the host where your web application is situated.

Here are some imperative points to recognize:

• Use the Ctrl-C shortcut to curtail a job.
• Use the Ctrl-Z shortcut to pause a job. The FG command can reestablish the paused job, and the bg command can relocate a job to the background for simultaneous execution. Alternatively, append an ampersand (“&”) to a command to commence it in the background.
• Use the “ps” command to view the ongoing processes. Each process holds a unique ID displayed in the first column. The “ps” command has supplementary options to modify the output.
• Use the “kill” or “killall” command followed by the process ID or name to break a job. For example, utilize kill 22064 or killall java.
• For specific job searching inside the process list, utilize the “grep” command. The “grep” command is a potent search tool with diverse configurations. For example, ps -aux| grep java filters the process list based on the search standard.

3 Major Ways How To Install New Software On Linux

Considering the distinct methods of installing new software in Linux. This is a significant topic, chiefly for former Windows users. Here are the most typical methods:

• Installing RPM packages
• Installing DEB packages
• Installing from tarballs (principally when coping with source code)

It’s crucial to be cognizant of software repositories. A repository is a storage area for packages, both source and binary, which can be accessed via the internet to install software on your system.

You can choose or even concoct your own repositories. The repository list is conventionally stored in configuration files such as /etc/yum.repos.d/ for YUM or /etc/apt/sources.list and /etc/apt/source.list.d/ for APT.

Recommended: Click here to understand more about installing new software/packages on Linux OS.

Basic Tools For Testing Linux Applications

We’ll presently dig into the technical components of testing Linux applications. Here are some basic instruments you’ll encounter during the testing process. The majority of these solutions are compatible with assorted Unix-based systems.

Let’s discuss the essential tools for testing Linux applications:

#1) GCC – Gnu C compiler
This is the primary compiler for C and C++ on Linux. To test the compiler, you can refer to the gcc site for specific tests. Compiling with the -g option facilitates debugging with gdb.

#2) bash
Bash shell is integrated into all Linux variants and is beneficial for script crafting.

#3) expect
Expect is a useful utility with a TCL-like syntax, commonly found in all variants.
– expect-perl or expect-python (pyexpect) – expect libraries for scripting languages such as Perl and Python.

#4) gdb – Gnu Debugger
Gdb is a rich feature debugger for C/C++ programs. It is a useful tool for debugging. For kernel-level debugging, you can use kgdb.

#5) ltt – Linux Trace Toolkit
If your Linux kernel supports LTT, you can monitor active processes and system calls in real-time.

#6) import? gimp
These instruments can be utilized to capture screenshots for the examination of graphics applications.

#7) minicom
Minicom is a program for manual testing. If you aspire to automate console operations, contemplate using expect or combine “cat” and “echo” commands, or directly access /dev/ttySx as a file (though this choice may not always work).

#8) ltp – Linux Test Suite Page
Ltp is a compilation of tests covering file structures, system calls, and more. It is an invaluable source for testing.

#9) Further usual tools:
– netperf: utility to test network performance
– ircp, irdump, openobex: utilities for infrared examination
– telnet, ssh: tools for remote shell. You can utilize expect or analogous tools to automate command execution on a remote system.

Conclusion

This concludes our discussion today. We have gone over numerous significant topics related to Linux, including FAQs, Linux nuances, process supervision, limitations, and more. We have offered valuable examples and …