#!/bin/bash
file='file.txt'
while read inter time
do
   printf "%s %s\n" "${inter}" "perl -e 'print scalar localtime("${time}") . "\n";"
done < "${file}"

Fa1/14 perl -e 'print scalar localtime(0) . n;
Se0/0/0 perl -e 'print scalar localtime(0) . n;
Fa1/11 perl -e 'print scalar localtime(0) . n;
Fa1/9 perl -e 'print scalar localtime(0) . n;
Fa1/0 perl -e 'print scalar localtime(0) . n;
Se0/0/1 perl -e 'print scalar localtime(1240421065) . n;
Gi1/0 perl -e 'print scalar localtime(0) . n;
Fa0/0 perl -e 'print scalar localtime(1240421065) . n;
Fa1/3 perl -e 'print scalar localtime(0) . n;
Fa1/8 perl -e 'print scalar localtime(0) . n;
Fa1/15 perl -e 'print scalar localtime(0) . n;
Fa1/13 perl -e 'print scalar localtime(0) . n;
Fa1/10 perl -e 'print scalar localtime(0) . n;
Fa1/1 perl -e 'print scalar localtime(0) . n;
Fa1/12 perl -e 'print scalar localtime(1240421065) . n;
Fa0/1 perl -e 'print scalar localtime(1240421065) . n;
Fa1/5 perl -e 'print scalar localtime(0) . n;
Fa1/6 perl -e 'print scalar localtime(0) . n;
Se0/0/0.1 perl -e 'print scalar localtime(0) . n;
Fa1/7 perl -e 'print scalar localtime(0) . n;
Fa1/2 perl -e 'print scalar localtime(0) . n;
Lo0 perl -e 'print scalar localtime(0) . n;
Fa1/4 perl -e 'print scalar localtime(1240421065) . n;