Have: a file such that some lines contain readable text and some lines are "blank."
The lines with readable text may have leading and/or trailing blanks.
The "blank" lines may contain zero or more blanks.
Want: a sed
which suffixes the "blank" lines with a readable character string such as "EOL".
No blanks may be added or destroyed.
I tried this ...
sed 's/^\([[:space:]].*\)$/\1EOL/' $InFile
... but it doesn't do the job.
Daniel B. Martin