explain plz

Shell Programming and Scripting
1

can u explain this step by step........plz...will it do the same

for I in *.tar.gz; do
A=`basename $I .tar.gz`
mkdir $A
cp marking-guide ${A}/$A
cd $A
gunzip -c ../$I | tar xf -
cd..
done

thnx
__________________

2

# loop thru all zip file archives (files ending .tar.gz)
for I in *.tar.gz; do
# set var A to whatever is before the .tar.gz
A=`basename $I .tar.gz`
# make a directory for the var A
mkdir $A
# copy file marking-guide to __
cp marking-guide ${A}/$A
# change directory to A
cd $A
# unzip __
gunzip -c ../$I | tar xf -
# change directory to one back
cd..
# done with loop
done

3

For each filename ending in .tar.gz (gzipped tar file)
for I in *.tar.gz; do

Filename without any path (including the .tar.gz)
A=`basename $I .tar.gz`
Make a directory with the same name as the file
mkdir $A
Copy something called marking-guide into the new directory with the same name as the .tar.gz file
cp marking-guide ${A}/$A
Move into the directory and decompress the file
cd $A
gunzip -c ../$I | tar xf -
Go back to the original directory in case there are more iterations of the loop
cd..
done