Assume that you have several files, with different extensions $($e$.$g$.,.$cpp$,.$txt$,.$dat, etc.$),$ present in your current directory on Linux server. The purpose of the script merge$\_$all is to merge all files present in your directory with an extension $($provided by the user$)$ into one single file. We need to write and test a bash script that is invoked as:$./$ merge$\_$all.sh para$1$ para$2$Where the shell parameter para$1$ represents the extension and para$2$ represents the name of the merged $($destination file$).$Example: $ $./$merge$\_$all.sh txt BackupThe above command will append all $.$txt files in the current directory to the file named Backup.Some important features of your script:$1.$ Your script appends all the files with the desired extension $($given as para$1)$ present in the current folder, one by one, to the file para$2\mathrm{.}2.$ After appending the files, the merged file specified in par$2$ should have the read and write permissions only to the owner, and none to the group or others$\mathrm{.}3.$ Your script should not make any assumption about the number and types of files present in the current directory. Appropriate messages should be printed in case of non$-$existence of the needed source files$\mathrm{.}4.$ You need to test your script with a variety of files with different extensions in the current directory$\mathrm{.}5.$ You will need to do a little research about extracting the extension type of a file in bash and about appending a file to another.