Shell Programming and Scripting

awk -vxyz=2       ####creating a variable in awk by -v option whose syntax is -vvariable_name=variable_value or -v variable_name=variable_value, so as per your requirement I have created variable named xyz and set it's value to 2.
'{if($0 ~ /PIN/)  ####Putting an if condition here, to check either a line is having value PIN in it, here $0 represents record(line).
{                 ####if above condition is TRUE, means a line has string PIN in it, so statements from this block will be executed now.
while(++a<=xyz)   ####starting a while loop here, where it should run until the variable named a's value is less than or equal to variable named xyz's value. Here point to be noted is I am giving ++a, which means before checking condition with variable named xyz it will increase the value of variable named a.
{                 ####So if condition in above while loop is TRUE then statements inside while loop will  be executed as follows.
getline;          ####mentioning "getline" here, it's an awk in-built keyword which tells cursor to go to next line(as we all know awk reads line one by one).
print $0;         ####Now when cursor goes to next line, I am giving the print command here, telling awk to print current line, because we need NOT to print the line which have "PIN" in it and print it after the number of lines which are given in variable xyz.
}                 ####while loop is getting closed here now.
;print "PIN";     ####printing the value of string "PIN" as in above while loop awk will print all lines which should be printed before new position of string "PIN", so printing it now.
a="";             ####Nullifying variable a now, reason because whenever next time a match found into your Input_file for string "PIN" into a line, a should be start from 0 else it may carry it's previous values and output could be diferent then.
next              ####stating next here, next is an awk's in-built keyword which forces cursor to move forward and NOT to execute the further all statements.
}}                ####if condition mentioned in line2 above is getting closed here.
1                 ####Mentioning 1 here, which means making a condition TRUE here. So awk works on condition{action/operation} syntax. So if any condition is TRUE it executes the further mentioned actions, so here when we are making condition RUE by mentioning it 1 here and no actions are mentioned by me so awk will do default action which is to print the current line.
                  ####So basically this 1 will print those lines which doesn't have string "PIN" in them.
'   Input_file    ####Mentioning Input_file here.

#!/bin/ksh
xyz=${1:-2}	# set default value for $xyz to 2, but use $1 if present.
if [ "${xyz#[+-]}" != "$xyz" ]
then	# $xyz is a signed value, clear $op
	op=
	# If $xyz is negative, decrement it by one to get the desired offset.
	[ "$xyz" -lt 0 ] && xyz=$((xyz - 1))
else	# $xyz is an unsigned value, set $op to a plus sign.
	op="+"
fi

# Use ed to move the first line that exactly matches the string "PIN" to the
# desired spot.
ed -s input.txt <<EOF
	H
	/^PIN$/;.m$op$xyz
	w
	q
EOF

awk '$0 ~ SRCH {LN = NR + ++XYZ; TMP = $0; next} NR == LN {print TMP} 1' SRCH=PIN XYZ=2 file
line_before_pin_1
line_before_pin_2
line_after_pin_1
line_after_pin_2
PIN
line_after_pin_3
line_after_pin_end

while read xyz
do
echo "$xyz" >>outputfile
if [ "a$xyz" = "aON" ]
then 
    echo "===" >>outputfile
fi
done <inputfile