Shell Programming and Scripting

#! /bin/ksh
# Not sure how to frame the if condition below
if [ input_redir = "Y" ]; then
  echo "Input Redirected from a file"
  Do Processing.....
else
  echo "No Input Redirection"
  Do Processing....
fi

./my.script

No Input Redirection

./my.script < test.file

Input Redirected from a file

file=$1
cat $file | while read line
do
    some...
done

#! /bin/ksh
numargs=$#
case $numargs in
0)
  echo "No. of Args : $numargs"
  echo "Parameter 0 = $0"
;;
*)
  echo "No. of Args : $numargs"
  i=1;
  for d in $@
  do
    echo "Parameter $i = `echo $d`"
    i=`expr $i + 1`
  done
;;
esac

$ ./my.script
No. of Args : 0
Parameter 0 = ./my.script

$ ./my.script < test.file
No. of Args : 0
Parameter 0 = ./my.script

$ ./my.script Hi this is a test text
No. of Args : 6
Parameter 1 = Hi
Parameter 2 = this
Parameter 3 = is
Parameter 4 = a
Parameter 5 = test
Parameter 6 = text

#! /bin/ksh

typeset inFile=""

while [ -n "$1" ] ; do
     case $1 in
          -f)
               shift
               inFile="$1"
               shift
               ;;

          -x)
               # some other option
               shift
               ;;

          *)
               print - "Error: unknown option"
               exit 1
               ;;

     esac
done

# if $inFile is empty the user has not specified any input file
if [ -n "$inFile" ] ; then
     # interactive operation goes here
else
     # batch operation goes here
fi

exit 0

exec 6<&0
while read line
do
echo $line
done<&6

exec 6<&-

sh test.sh < file