Shell Programming and Scripting

I'd like to read a file (mydata.dat) line by line. The file consists of 5 columns filled with numbers, like so:

Code:

    83.018     1.953    49.587   20550.000  353
    83.213     1.953    49.195   20600.000  171
    84.935     1.954    48.803   20650.000  920

For every read line (i.e. in every step of the loop), I'd like to read the 4th number in that line (e.g. 20550.000 in the first line above) into a variable arg4. The first, second and third numbers (e.g. 83.018, 1.953, 49.587) I'd like to write to a file (outfile_${arg4}) whose name should contain the 4th number.

E.g. file 'outfile_20550.000' contains

Code:

83.018     1.953    49.587

This is what I came up with, but it doesn't work yet..

Code:

while read line;
do      
      arg4=`echo  | awk '{ print $4 }' $line`
      echo | awk `{ print $1, $2, $3 }` $line >> outfile_${arg4}   

done < mydata.dat

Moderator's Comments:

Please use code tags for your data and code next time

Code:

while read a b c d rest
do
    echo "$a $b $c" >> outfile_$d
done < mydata.dat

Beautifully simple! Thanks a lot :-)
I'm new to shell scripting and very much appreciate your help.