UNIX for Dummies Questions & Answers

$   ls

test1.txt   test2.txt   test3.txt

$   change_filename test1.txt
$   ls

test1_fails.txt   test2.txt   test3.txt

#! /usr/bin/bash
base=$1
if [ -f ${base} ];
then
    mv ${base} ${base/./_fails.}
else
    echo "${base} file not found"
fi

#! /bin/csh

base=$1

if [ -f ${base} ]
then
   cp ${base} ${base././_fails.}
else
   echo "${base} file not found"
fi

$ change_filename test1.txt
base=test1.txt: Command not found
base: Undefined variable

#! /bin/csh

base=$1

if [ -f ${base} ]
then
cp ${base} ${base/./_fails.}
else
echo "${base} file not found"
fi