Shell Programming and Scripting

Hi all, I'm needing help again on scripting. I have weekly files with 3 columns, and I need to do monthly averaging on the values on column 3, the file naming convention is as follows:

Code:

20000105.u- 2000:year 01:month 05:day
20000112.u
20000119.u
20000126.u
20000202.u
20020209.u

I need to do a loop that will read the month part of each filename and do the average of column 3 for all the files falling on the same month. the desired output will be something like:

Code:

200001.u containing 3 columns still:
cols.1 & 2: the values are the same for all files and so just need to append them to the final output
col.3: average of col. 3 from 20000105.u - 20000126.u

Suggestions are very much welcome and appreciated. thanks much.

On the side, I had another question partly unrelated to the ones on top. Is there a way to change the filename on a directed output automatically, like for instance in the pseudo-code below. thanks again

Code:

list="$(ls *.u)"
for i in $list; do
    command > "$i".out
done

directed output name: file.u.out
desired output name: file.out

thanks a lot,

Code:

ksh
for i in *.u
do mv $i "${i%.u}.out"
done

Code:

  command > "${i%.*}.out"

--ahamed

I might be being daft myself, but i don't quite understand your need. Do youIf it's option a, I could write a cheap & nasty shell script, but I'm sure an awk would be far superior. If it is options b then it might be simpler as a script.

Code:

#/bin/ksh
read col1 col2 f1col3 rest < $1
read col1 col2 f2col3 rest < $2
((tot=$f1col3+$f2col3))
((avg=$tot/2))
echo "The average for column 3 in $1 & $2 is $avg

Of course, this doesn't handle the half and isn't very flexible. You could multiply the $avg by 2 and if it's different to $tot, then display the extra half.

Can you elaborate on your needs a bit better?





On the second point, if you have a files called filenames.u.out and you want to create filenames.out from them, you could try something like:-

Code:

#!/bin/ksh
for source in *.u.out
do
   target="${source%.u.out}.out"
   mv $source $target
done

The definition of target is a way to chop off the end of a string, to which I then appended .out again. I might have the wrong end of the stick again I suppose.




Robin
Liverpool/Blackburn
UK

thanks a bunch. worked seamlessly,

You are welcome. What worked for what problem?



Robin

For the averaging part, do you provide an input? i.e. get me the average for this particular month or do you want to averga out for all the files present in a directory by month?

--ahamed