Question

I have the following code:

#!/bin/bash

for f in `find . ! -type d`;
do
        line=`grep -i 'todo' $f | sed 's/^[ \t]*//'`
        if [ $line ]; then
                echo "$f:"
                echo "$line"
        fi
done

but the condition is not working as I would expect it, I need it to only work if something other than an empty string (or nothing) is returned by the command.

Answer 1

Some ideas:

• You need to quote your $f in the grep line to deal with files with spaces in their names.
• Perhaps you should use -f rather than ! -d, otherwise your find may hang on fifos.
• For me the \t escape didn’t work as a tab match, it consumed a leading t in a test case file line, so I just inserted a raw tab character in the script instead.
• Use the double square bracket test otherwise you need an operator in there, or at least some quotes.

A slight variation on your script would then be:

find . -type f | while read f
do
        # raw tab in here ------------------- v
        line=`grep -i 'todo' "$f" | sed 's/^[  ]*//'`
        if [[ $line ]]; then
                echo "$f:"
                echo "$line"
        fi
done