#!/bin/bash
#This is mycat. Similar to cat.
#For detailed information use path/to/mycat.sh -h option

arguments=$#

if [[ "$arguments" -eq 0 ]] #in case of standard input
then
while [[ "$input" != "EndInput" ]]
do
read input
echo $input
done
else
case $1 in #take action according to specified option
  	"-n")
		nl < $2 #number lines
  		;;

  	"-E")
   	sed 's/$/$/' < $2 #redirect file and add $ at the end of each line
  		;;

        "-A"
        sed 's/   /^I/g' < $2 > newfile.list
        sed l < newfile.list
                ;;

        "-T"
        sed 's/   /^I/g'
                ;;

  	"-h")
		echo
		echo "mycat. Concatenates and/or displays files from standard input to standard output for free."
		echo
		echo "SYNOPSIS"
		echo "   /path/to/mycat.sh [OPTION] [FILE]"
		echo
		echo "OPTIONS"
		echo "   -n                         number all output lines"
		echo "   -E                         displays $ at the end of each line"
		echo "   -h                         to display help"
		echo "   -T                         display tabs as ^I"
                echo "   -A                         show -all"
                echo
		echo "EndInput to end"
		;;

  *) #case with more than one file.
  while [ "$arguments" -ne 0 ]
  do
  line_number=1
  last_line=$(tail -1 < $1) 
  while [[ "$last_line" != "$line_to_display" ]] #go through the whole file
  do
  last_line=$(tail -1 < $1)
  line_to_display=$(head -$line_number < $1 | tail -1) #display current line
  echo "$line_to_display"
  ((line_number++))
  done
  shift #go to next file and decrease $# with 1
  arguments=$# 
  done;;
 esac
fi
exit 0