How to remove filenames having the same extension.?

Shell Programming and Scripting
1

hi,

i have a directory which contains some files and a subdirectory. i am writing only the files names to a file using the below code.

ls -ltr | grep "^-" | awk '{print $NF}' > /home/file_list$$

cat /home/file_list$$
s1_abc.txt
s2_def.xls
s3_def.xls

as you can see there is one .txt file and 2 .xls file.
i want to keep any one file for each extension. i.e i want to have unique file for each extension. so the

will have only the following contents

s1_abc.txt
s2_def.xls

how can i do this?

2

Hello,

Could you please use the following code.

Lets say here is the file with details.

$ cat remove_duplicate_extension
s1_abc.txt
s2_def.xls
s3_def.xls
s4_def.txs
s5_def.txt
s6.def.excel
s7.def.lxs

Here is the script for same.

 
$ cat remove_duplicate_extension.ksh
#value_check_b=0
while read line
do
a=`echo $line`
value_check_a=`echo $line | awk -F. '{print$2}'`
#echo $value_check_a
if [[ $value_check_a == $value_check_b ]]
then
echo ""
else
echo $line
fi
value_check_b=`echo $line | awk -F "." '{print$2}'`
done < "remove_duplicate_extension"

Output should be as follows.

$ ksh remove_duplicate_extension.ksh
s1_abc.txt
s2_def.xls
s4_def.txs
s5_def.txt
s6.def.excel

Please let me know if this helps.

Thanks,
R. Singh

3

but in your output you are getting two .txt files.
i want a single file with each extension regardless of the file names.

4 
perl -e 'opendir(DIR , $ARGV[0]); chdir $ARGV[0]; while (readdir DIR ){($f)=$_=~/\.([^\.]+)$/;if ((-f $_ )&& (! defined $seen{$f})){$seen{$f}++; print "$_\n";}}' $DIRECTORY
5 
sed 's/\(.*\)\./\1%/g' file_list | sort -t'%' -u -k2 | tr '%' '.'
6

sample below uses the same list as ravinder ... not as elegant as balajesuri's code but should be easy enough to understand ...

[root@centosgeek ~]# for ext in $(awk -F"[._]" '{print $NF}' testfile2 | sort -u);
> do
>     grep $ext testfile2 | head -1
> done
s6.def.excel
s7.def.lxs
s4_def.txs
s1_abc.txt
s2_def.xls
[root@centosgeek ~]#
7 
$ cat a.txt
s1_abc.txt
s2_def.xls
s3_def.xls
s4_def.txs
s5_def.txt
s6.def.excel
s7.def.lxs


$ awk -F\. '!a[$NF]++' a.txt
s1_abc.txt
s2_def.xls
s4_def.txs
s6.def.excel
s7.def.lxs
1 Like
8

Your simple code could even have an easy variation as well. Simply removing ! would print those that are to be excluded instead. This is useful if they are to be deleted.

awk -F. 'a[$NF]++' a.txt