# cat xarg.txt 
#! /usr/bin/ksh
for logfile in `find . -name "*.log*"`
do
    echo "$logfile:"
    sed -n '/error/=' $logfile
done

files=($(find . -name "*log*"))
echo "The length is ${#files[@]}"
for file in ${files[@]}
do
    echo "$file"
    awk '/error/{print NR}' $file
done
#./xarg.txt 
./dir/b.log:
1
2
3
4
./a.log:
1
3
4
The length is 2
./dir/b.log
1
2
3
4
./a.log
1
3
4