I have several Ubuntu servers and there is some behavior that has me curious.
On any newly installed machine (Ubuntu Server 12.04.3 LTS), if I run:
echo "testbla123" | grep -P -o [0-9]*
This will return
123 as expected.
On an older machine (Ubuntu Server 12.04.1 LTS), if I run the same command, I get nothing back, I have to instead run:
echo "testbla123" | grep -P -o "[0-9]*"
After performing an
apt-get upgrade, it will perform without quotes around the regex.
Grep is at the same versions on both machines. I tried comparing dependencies before and after the update for some time without much luck.
I was wondering if anyone knows why this happens?