SimpleBash.sh

#! /bin/bash

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# TASK 1
#############################################

# HOME directory can be accessed through 2 environment variables on most systems
# $HOME and ~

cd ~

# is the same as, works in Windows too

cd $HOME

# mkdir -p
# Create intermediate directories as required.  If this option is not specified,
# the full path prefix of each operand must already exist.  On the other hand,
# with this option specified, no error will be reported if a directory given as
# an operand already exists.  Intermediate directories are created with
# permission bits of rwxrwxrwx (0777) as modified by the current umask, plus
# write and search permission for the owner.

mkdir -p ./bin

# Change directories (cd) to the one you just made

cd ./bin

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# TASK 2
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# Copy (cp) file from directory relative directory
# ie: the directory above
# In the first synopsis form, the cp utility copies the contents of the
# source_file to the target_file.  In the second synopsis form, the contents of
# each named source_file is copied to the destination target_directory.  The
# names of the files themselves are not changed.  If cp detects an attempt to
# copy a file to itself, the copy will fail.

cp ../famous.dat famous.data

mkdir -p datafiles

# Copy the new copy to another filename and directory

cp ./famous.data ./datafiles/famous.backup

# Make a hard link
# The ln utility creates a new directory entry (linked file) which has the same
# modes as the original file.  It is useful for maintaining multiple copies of a
# file in many places at once without using up storage for the ``copies'';
# instead, a link ``points'' to the original copy.  There are two types of
# links; hard links and symbolic links.  How a link ``points'' to a file is one
# of the differences between a hard and symbolic link.

ln ./famous.data ./datafiles/famous.hard

# Make a soft link (-s Create a symbolic link.)

ln -s $HOME/bin/famous.data $HOME/bin/datafiles/famous.soft

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# TASK 3
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# pwd - Print Working Directory

pwd
ls -la . datafiles
ls -lL datafiles

# http://linuxcommand.org/lc3_lts0080.php
# d)
ls -lL ./datafiles/*.*{f,u}*

# e)
ls -lL **/*.[[:lower:]]*{t,r}?

Bracket expansion tells the command line interpreter that you want this command expanded outward based on your criteria

ls -lL **/*.[[:lower:]]*{t,r}?
ls -lL list command with 2 flags
**/ a pattern to match any directory under the current one
*. matches anything any length up until a dot (.) occurs
[[:lower:]] is any lowercase character you could use upper, and other options
* another wildcard for any number or any type of character
{t,r} bracket expansion is the equivalent to typing ls -lL **/*.[[:lower:]]*t?and ls -lL **/*.[[:lower:]]*r?
? is a single character wildcard, which means matches can only have 1 more character in them, or second to last