Reading and writing files interactively

This next script is similar to one in Chapter 5, Creating Interactive Scripts. It reads the file specified, displays a form, and allows the user to edit and then save it:

Chapter 7 - Script 6

#!/bin/sh
# 6/2/2017
# Chapter 7 - Script 6

trap catchCtrlC INT          # Initialize the trap

# Subroutines
catchCtrlC()
{
 move 13 0
 savefile
 movestr 23 0 "Script terminated by user."
 echo ""                     # carriage return
 exit 0
}

cls()
{
 tput clear
}

move()                       # move cursor to row, col
{
 tput cup $1 $2
}

movestr()                    # move cursor to row, col
{
 tput cup $1 $2
 echo -n "$3"                # display string
}

checktermsize()
{
 rc1=0                       # default is no error
 if [[ $LINES -lt $1 || $COLUMNS -lt $2 ]] ; then
  rc1=1                      # set return code
 fi
 return $rc1
}

init()                       # set up the cursor position array
{
 srow[0]=2;  scol[0]=7       # name
 srow[1]=4;  scol...