Find and rename part of a file

Shell Programming and Scripting
1

hi,
Need your help.
I need to write a script for below..
i have two files in directory

/home/abc

as below:

 
Watch_20140203_abc.dat
Watchnow_20140203_abc.dat

I have to copy this file from

 
/home/abc to /home01/home02

after that i have to rename the date part in above two files with the input date that that i should be able to pass as part of my script.

i copied the file as below:

 
cp /home/abc /home01/home02

Not sure how to proceed after that..Please help.

2

I did not test this and I didn't bother to check to see if
the date in the filename is an actual date, I just parsed
based on the fact that if you use "_" as a delimiter.

input_string=${1}
source_dir="/home/abc"
target_dir="/hom01/home02"
ls ${source_dir} | while read infile
do
        pre=`echo ${infile} | cut -d"_" -f1`
        post=`echo ${infile} | cut -d"_" -f3`
        new_name="${pre}_${input_string}_${post}"
        cp ${source_dir}/${infile} ${target_dir}${new_name}
done