Search for tabs, without -P, using 'grep'

Question

I used to use grep -P successfully earlier, till I got a machine where grep is not compiled with Perl regular expression support. Now I am having trouble matchi

Answer 1

Try this instead:

grep -G $'\t'

For more info please see bug #23535: Grep Doesn't Support \t as a tab character.

Answer 2

The Perl-RegEx understand '[\t]', so you can do like this:

echo -e "\t : words" | grep -P '^[\t]'

the basic-regexp and extended-regexp need for these a "blank" (RegEx for "Space" / "Tab"):

echo -e "\t : words" | grep -G '^[[:blank:]]'
echo -e "\t : words" | grep -E '^[[:blank:]]'

maybe you can use it this way:

echo -e "\t : words" | grep -E '^[[:blank:]]{2,8}'
echo -e "\t : words" | grep -G '^[[:blank:]]\{2,8\}'