ifup eth0 ERROR /sbin/ifup: line 268: [: : integer expression expected

From:http://h30499.www3.hp.com/t5/Networking/sbin-ifup-line-268-integer-expression-expected/m-p/3545538#M4181

vi /sbin/ifup

找到下面部分：

# DHCP likes to create duplicate routes. Fix that up.
NUMDEFROUTES=`ip -o route | \
grep "^default" | \
awk '{ nlines++ } END { print nlines }'`
if [ -n "$NUMDEFROUTES" -a "$NUMDEFROUTES" -gt 1 ]; then
# remove the default route for the new device (old route wins)
ip route del default dev ${DEVICE}
fi
# end dynamic device configuration

将其该为：
NUMDEFROUTES=`ip -o route | \
grep "^default" | \
awk 'BEGIN { nlines = 0 } { nlines++ } END { print nlines }'`

这就使得NUMDEFROUTES有了一个interger 值