Shell Programming and Scripting

You can do it entirely within the shell; there is no need for external commands:

Code:

while IFS= read -r path
do
  file=${path##*/}
  ext=${path##*.}
  printf "PATH:  %s\nFILE: %s\n EXT: %s\n\n" "$path" "$file" "$ext"
done < FILENAME

###

Do you mean something like this?
(this is zsh)

Code:

$ while read;do print "name: \"$REPLY:t:r\"  extension: \"${${REPLY:e}:-null}\"";done<infile
name: "a"  extension: "java"
name: "perl"  extension: "null"
name: "gtar"  extension: "null"
name: "abcd,efgh_ijkl.mnop"  extension: "xml"

Thanks guys for your quick replies! Here is a summary of my testing the various solutions proposed by various people above :

cfajohnson - For some reason your solution returned PATH value for EXT when filename didn't have extension (e.g. /usr/local/bin/perl)

radoulov - Sorry couldn't test your solution because I am using sh and ksh only on our boxes. So can't really tell whether it works

Shell Life - Your solution worked like charm and handled all possible filetypes I have in my test environment

thanks again for helping me out! appreciate it.

So here is the solution I landed up using in my script :

#################################################

#!/bin/sh

for cfilename in `cat filelist.txt | sort -u`
do
filename_w_ext=`basename $cfilename`
filename=`echo $filename_w_ext | sed 's;\(.*\)\..*;\1;'`
if [ ${#filename_w_ext} -eq ${#filename} ]; then
file_extension=''
else
file_extension=`echo $filename_w_ext | sed 's/.*\.//'`
fi
echo $filename_w_ext
echo $filename
echo $file_extension
done

Which is why I followed it up with a correction.

That will fail if any of the lines contain spaces.

And cat is unnecessary:

Code:

for cfilename in `sort -u filelist.txt`

If you want the file sorted, and duplicates removed, use:

Code:

sort -u filelist.txt | while IFS= read -r path
do
  file=${path##*/}
  case $file in
    *.*) ext=${path##*.} ;;
    *) ext= ;;
  esac
  printf "PATH:  %s\nFILE: %s\n EXT: %s\n\n" "$path" "$file" "$ext"
done



###

This script will be orders of magnitude faster than one which calls external commands (three of them!) for every line of the file.