Consider this command:
printf 'alpha\nbravo\ncharlie\n' | grep --line-regexp --quiet bravo
grep sees 3 lines separated by newline, and matches the bravo line. Now consider this command:
printf 'alpha\0bravo\0charlie\0' | grep --line-regexp --quiet bravo
My thinking tells me that because I have not used --null-data
, grep should see
1 or even 0 lines separated by newline, and fail to match a bravo
followed by
newline. However it does not, it succeeds just like the first command, why is
this?
This behavior was introduced with Grep 2.21:
So what happens now is that with binary data, all non-text bytes (including newlines) are treated as line terminators. If you want to change this behavior, you can:
use
--text
. This will ensure that only newlines are line terminatorsuse
--null-data
. This will ensure that only null bytes are line terminators