$
$ # my dummy file that will be used by my simple awk script
$ cat -n f73
   1  AAA 10
   2  BBB 20
   3  CCC 30
$
$
$ # my shell script
$ cat -n f73_test.sh
   1  #!/usr/bin/bash
   2
   3  #
   4  # The "system" function runs the host (Unix/Linux) command
   5  # and prints the output, if any.
   6  # The awk script sums up the 2nd column in file "f73" and
   7  # prints it at the end.
   8  #
   9  awk ' BEGIN { dt = system("type bash") }
  10        { sum += $2 }
  11        END { print sum","dt }
  12      ' f73
  13
$
$ ./f73_test.sh
bash is /usr/bin/bash        <== this came from "BEGIN"
60,0                         <== and the "0" came from "END"
$
$

$
$ # another shell script working on the same data file "f73"
$
$ cat -n f73_test1.sh
   1  #!/usr/bin/bash
   2
   3  # capture the 1st parameter in a variable called "mydate"
   4  mydate=$1
   5
   6  #
   7  # pass the variable "mydate" to the awk script that sums
   8  # the 2nd column in the file "f73"
   9  #
  10  awk -v dt=$mydate ' { sum += $2 }
  11                      END { print sum","dt }
  12                    ' f73
  13
$
$ # invoke the shell script now, passing a parameter
$ ./f73_test1.sh `date +%D`
60,11/02/12
$
$