Date: Mon, 28 Sep 2015 13:37:35 +0200 From: "no@spam@mgEDV.net" <nospam@mgedv.net> To: <freebsd-questions@freebsd.org> Subject: 10.2-RELEASE/amd64: grep regex syntax vs. grep-bug Message-ID: <00e801d0f9e2$125ec430$371c4c90$@mgedv.net>
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hi folks,
the goal: grep, that a variable contains a number and JUST digits.
# setup sample variable - we're on /bin/sh @ 10.2-RELEASE/amd64.
x=""
# od output the content of the variable to ensure content
echo "$x" | od -ctdC
0000000 \n
10
0000001
# now try /usr/bin/grep'pin (C locale) that it contains...
# ^ at BOL...
# [0-9] require a digit
# * ... and digits following
# $ ...until we reach EOL
# ... but...:
echo "$x" | grep -c '^[0-9]*$'
1 <== WHY?
it works if i remove the *, but this would only work for 1digit nrs.
is this a grep bug or my false understanding of how '*' works?
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