What Is $$ In Shell Script?

The main reason why Linux is not popular on the desktop is that it doesn’t have “the one” OS for the desktop as does Microsoft with its Windows and Apple with its macOS.

If Linux had only one operating system, then the scenario would be totally different today.

Linux kernel has some 27.8 million lines of code..

What’s the difference between Alexa and echo?

Alexa is specifically the name of the virtual assistant – the disembodied voice you talk to, ask questions, and bug with song requests. Amazon’s Echo is simply the name given to the physical products themselves, the speakers which house the AI Alexa. … For more information see our list of Alexa compatible devices.

Do hackers use Linux?

Linux is an extremely popular operating system for hackers. … Malicious actors use Linux hacking tools to exploit vulnerabilities in Linux applications, software, and networks. This type of Linux hacking is done in order to gain unauthorized access to systems and steal data.

Which Linux OS is best?

10 Most Stable Linux Distros In 20212| Debian. Suitable for: Beginners. … 3| Fedora. Suitable for: Software Developers, Students. … 4| Linux Mint. Suitable for: Professionals, Developers, Students. … 5| Manjaro. Suitable for: Beginners. … 6| openSUSE. Suitable for: Beginners and advanced users. … 8| Tails. Suitable for: Security and privacy. … 9| Ubuntu. … 10| Zorin OS.Feb 7, 2021

What is difference between Bash and Shell?

Bash (bash) is one of many available (yet the most commonly used) Unix shells. … Shell scripting is scripting in any shell, whereas Bash scripting is scripting specifically for Bash. In practice, however, “shell script” and “bash script” are often used interchangeably, unless the shell in question is not Bash.

What is $0 shell?

$0 Expands to the name of the shell or shell script. This is set at shell initialization. If Bash is invoked with a file of commands (see Section 3.8 [Shell Scripts], page 39), $0 is set to the name of that file.

Is there a monthly charge for using the Amazon Echo?

No, the Amazon Echo requires no monthly service fee, but it is important to note that when you register your Amazon Echo for the first time, you will get 1 free month of Amazon Prime, which includes Amazon Prime Music (the default Amazon Echo Music Service).

What is $2 in shell script?

$0 is the name of the script itself (script.sh) $1 is the first argument (filename1) $2 is the second argument (dir1) $9 is the ninth argument.

How much does Linux cost?

That’s right, zero cost of entry… as in free. You can install Linux on as many computers as you like without paying a cent for software or server licensing.

When should you make clean?

You run make clean in two situations – when you want to package up the source code (and therefore don’t need/want the built objects) OR when you have some reason to believe that the built objects are bad. In your case, you’re using ‘make clean’ to fix a problem that is likely the result of a buggy Makefile.

Is Makefile a shell script?

put a command in a file and it is a shell script. a Makefile however is a very clever bit of scripting (in it’s own language to all extents) that compiles an accompanying set of source code into a program.

What is $? In Unix?

$? -The exit status of the last command executed. $0 -The filename of the current script. $# -The number of arguments supplied to a script. $$ -The process number of the current shell. For shell scripts, this is the process ID under which they are executing.

Why is Linux bad?

While Linux distributions offer wonderful photo-managing and editing, video-editing is poor to non-existent. There is no way around it — to properly edit a video and create something professional, you must use Windows or Mac. … Overall, there are no true killer Linux applications that a Windows user would lust over.

What does echo $$ do?

echo $? will return the exit status of last command. … The last command gave output 0 since the echo $v on the line previous finished without an error. If you execute the commands. v=4 echo $v echo $?

What is $$ in Makefile?

$$ means be interpreted as a $ by the shell. the $(UNZIP_PATH) gets expanded by make before being interpreted by the shell. –

Why do we use Makefile?

The make utility requires a file, Makefile (or makefile ), which defines set of tasks to be executed. You may have used make to compile a program from source code. Most open source projects use make to compile a final executable binary, which can then be installed using make install .

What can Windows do that Linux can t?

What Can Linux Do that Windows Can’t?Linux will never harass you relentlessly to update. … Linux is feature-rich without the bloat. … Linux can run on almost any hardware. … Linux changed the world — for the better. … Linux operates on most supercomputers. … To be fair to Microsoft, Linux can’t do everything.Jan 5, 2018

Whats the difference between ECHO and Alexa?

Alexa is the virtual assistant, while Echo is the smart speaker device.

What is $$ Linux?

$$ is the process ID (PID) of the script itself. $BASHPID is the process ID of the current instance of Bash. This is not the same as the $$ variable, but it often gives the same result. https://unix.stackexchange.com/questions/291570/what-is-in-bash/291577#291577. Share.

Is Windows 10 better than Linux?

Linux has good performance. It is much quicker, fast and smooth even on the older hardware’s. Windows 10 is slow compared to Linux because of running batches at the back end, requiring good hardware to run. Linux updates are easily available and can be updated/modified quickly.

What are the disadvantages of Linux?

What are the Disadvantages of Using Linux?There’s no standard edition of Linux. … Linux has patchier support for drivers (the software which coordinates your hardware and your operating system). … Linux is, for new users at least, not as easy to use as Windows.More items…•Oct 25, 2008