problem in shell script

[Popup123]

Can somebody explain how $IFS is used?

I have to modify following piece of code acccording to my needs.
But I am unable to understand it. I have to read a log file written as:-
0.001
0.002

tot=0.0
max=0
npts=0
totpts=0
for file in `ls -1 logs/*.log`; do

   oldifs=$IFS
   IFS=:

   while read str tim; do

      tim=`echo $tim | sed -e "s/^ //g"`

      tot=`echo "$tot + $tim" | bc -l`

      npts=`expr $npts + 1`

      totpts=`expr $totpts + 100`

      break

   done<$file

   IFS=$oldifs
done

I am using bash. I had inserted echo statement for tim but it comes out to be empty instead of 0.001.
sed -e "s/^ //g" removes blank spaces I think.

[drl]

Hi.

IFS The Internal Field Separator that is used for word splitting
after expansion and to split lines into words with the read
builtin command. The default value is ``<space><tab><new-
line>''.

-- man bash

cheers, drl

[scm]

sed -e "s/^ //g" removes blank spaces I think.

No, it removes a single space from the beginning of a line. The 'g' is redundant since there is only one beginning of line (matched by the ^). To remove all leading whitespace use

sed 's/^ *//'

[Popup123]

Hi,
Thanks. How does this while read str works? I think in this code file has not been opened because ls -1 .. in for loop will only give file name.

[Franklin52]

Hi,
Thanks. How does this while read str works? I think in this code file has not been opened because ls -1 .. in for loop will only give file name.

The read command reads 2 variables which are seperated by a space or tab in the found file.
Here's where the file is opened that's found in the for loop with the ls command:

done<$file

Regards

[Cabhan]

It might help us solve your problem if we knew what you were trying to do. Can you explain what you want this script to end up doing? Based on what I understand of your problem, for instance, you have no need to modify $IFS at all...