Question

Using a Linux terminal, write a script, called UnixHistory.sh, which will generate an abbreviated

"tree" of the Unix and Unix like operating system ancestry. The data source, as

always, can be found on Wikipedia:

https://en.wikipedia.org/wiki/File:Unix_history.svg

The Unix history begins with a directory named ResearchUnix that has two

children: BSD and Commercial.

BSD has two children FreeBSD and NextStep, NextStep has a single child

directory: MacOSX.

Commercial has one sub-directory named Solaris

NOTE all the elements mentioned above are directories, created with the mkdir

command. We haven't discussed any files (yet).

Inside of each directory, there should be a regular file called Year (create

this with an echo > command, just as we have in lecture). The Year file holds

the approximate beginning date for each Unix variant. Here is a list of values

for the corresponding Unix variant:

ResearchUnix = 1972

Commercial = 1984

BSD = 1977

Solaris = 1991

FreeBSD = 1993

NextStep = 1988

MacOSX = 2002

A sample run of your script must look like this:

$ bash UnixHistory.sh

$

Which is to say nothing should be printed if all went well.

You can check your work with the find command:

$ find

.

./UnixHistory.sh

./ResearchUnix

./ResearchUnix/BSD

./ResearchUnix/BSD/NextStep

./ResearchUnix/BSD/NextStep/Year

./ResearchUnix/BSD/NextStep/MacOSX

./ResearchUnix/BSD/NextStep/MacOSX/Year

./ResearchUnix/BSD/Year

./ResearchUnix/BSD/FreeBSD

./ResearchUnix/BSD/FreeBSD/Year

./ResearchUnix/Commercial

./ResearchUnix/Commercial/Solaris

./ResearchUnix/Commercial/Solaris/Year

./ResearchUnix/Commercial/Year

./ResearchUnix/Year

$ cat ResearchUnix/BSD/NextStep/Year

1988

$ cat ResearchUnix/Commercial/Solaris/Year

1991

$

You will probably want to check all the Year files to be sure of a high grade...

The order of output from find does not have to exactly match the example above.

But the directory structure under ResearchUnix must be precisely as described.

Answer 1

#!/bin/bash
#this is to create directory structure with parent directory ResearchUnix
mkdir -p ResearchUnix/{BSD/{FreeBSD,NextStep/MacOSX},Commercial/Solaris}
#find command to find directory and sub directtory in current directory
dir=`find . -type d`
for i in $dir
do
        if [[ $i != '.' ]]; then
                #statements
                #in each directory path create file year
                touch $i/year 

        fi

done
echo 1972 > ResearchUnix/year
echo 1984 > ResearchUnix/Commercial/year
echo 1977 > ResearchUnix/BSD/year
echo 1991 > ResearchUnix/Commercial/Solaris/year
echo 1993 > ResearchUnix/BSD/FreeBSD/year
echo 1988 > ResearchUnix/BSD/NextStep/year
echo 2002 > ResearchUnix/BSD/NextStep/MacOSX/year

this will do precisely as stated.give file permission before execute using chmod command.

If have any query in understanding this please ask