UNIX for Advanced & Expert Users

> ls
./  ../  ABCDEF.txt  AbCdEf.txt  AbcdEf.dat  abcdeF.txt  match_names*  text_review

> cat match_names 
#! /bin/bash

ls *.txt >text_review

while read zf
   do
   file2=$(echo "$zf" | tr [A-Z] [a-z])
   if [ "$file2" = "abcdef.txt" ]
      then 
      cat "$zf" 
   fi
done <text_review

> match_names 
You are inside ABCDEF.txt file
You are inside AbCdEf.txt file... yes...
You are inside abcdeF.txt  .. congrats

#!/bin/bash -

# @(#) s1       Demonstrate filter ignoring case.

echo
echo "(Versions displayed with local utility \"version\")"
version >/dev/null 2>&1 && version =o $(_eat $0 $1) grep
echo

FILES="ABCDEF.txt AbCdEf.txt AbcdEf.dat abcdeF.txt"
rm -f $FILES

touch $FILES
echo " Files currently extant:"
ls

echo
echo " Result of filtering, ignoring case:"
ls -1 |
grep -i abcdef.txt

exit 0

% ./s1

(Versions displayed with local utility "version")
Linux 2.6.11-x1
GNU bash 2.05b.0
grep (GNU grep) 2.5.1

 Files currently extant:
ABCDEF.txt  AbCdEf.txt  AbcdEf.dat  abcdeF.txt  readme.txt  s1

 Result of filtering, ignoring case:
ABCDEF.txt
AbCdEf.txt
abcdeF.txt

FILEA='[Tt][Ee][Ss][Tt][Ff][Ii][Ll][Ee]1.[Tt][Xx][Tt]' 

if [ ! -f $FILEA ]
then
        echo file does not exists
else
        echo file exists
fi