1. $1 , $2 , $3 - what should this variable use for? when to use it? is this a parameter to be pass in when we run the ./movem.sh?

yes, they are the parameters, pretend i gave them names.

2. keepthisone - what should this variable use for? when to use it? is this a parameter to be pass in when we run the ./movem.sh? or I need to put in the value here?

pretend i called this variable 'the_most_recent_file'.

3. movethisone - what should this variable use for? when to use it? is this a parameter to be pass in when we run the ./movem.sh? or I need to put in the value here?

pretend i called this variable 'not_the_most_recent_file'

#!/bin/sh

files_to_check=$1
command_to_run=$2
the_destination=$3

echo "# looking for files matching $files_to_check"

# ls -t sorts files by last modification time, most recent to oldest

ls -t $files_to_check |
(

  # the first line will be the most recent file

  read the_most_recent_file
  echo "# do nothing with the most recent file: $the_most_recent_file"


  # the rest of the lines will not be the most recent file

  echo "# do something with the rest of the files"
  while read not_the_most_recent_file
  do
   echo $command_to_run $not_the_most_recent_file $the_destination
  done
)
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