It is a relative simple task that can be accomplished with a tiny bit of dash, bash, perl, or your other favorite language, in a few if not just one line. However, having to figure it out 4 or more times a week adds up --especially now-days that I have better things to do than showing off my command line slutness to junior sysadmins. Here is the weed-out-from bash script I put together and officially added to my toolbox. It is certainly not the most efficient way of doing it but hey!
weed-out-from
#!/bin/bash
#weed-out-from - g0 2012 , aLog.IPduh.com
function help {
echo "weed-out-from usage: weed-out-from infected-list list-of-weeds"
exit 3
}
if [ -z $1 -o -z $2 ]
then
help
fi
if [ ! -f $1 ]
then
echo "weed-out-from: I cannot read the file $1"
help
fi
if [ ! -f $2 ]
then
echo "weed-out-from: I cannot read the file $2"
help
fi
DIRTY=$1
DIRT=$2
for i in `cat $DIRTY`
do
grep -i $i $DIRT &> /dev/null
if [ $? -ne 0 ]
then
echo $i
fi
done
weed-out-from usage:
$ cat spring-garden-before Windflower groundsel Azaleas Allium pigweed Belladonna-Lily Strelitzia Bloodroot Calla-Lily Cornflower Cosmos kikuyugrass Crocus Crabgrass Dahlia spurge Bermudagrass
$ cat list-of-weeds groundsel pigweed kikuyugrass Crabgrass spurge Bermudagrass
$ weed-out-from spring-garden-before list-of-weeds Windflower Azaleas Allium Belladonna-Lily Strelitzia Bloodroot Calla-Lily Cornflower Cosmos Crocus Dahlia
Note: List elements may be separated by new lines or space.
Install weed-out-from for all users:
# wget http://kod.ipduh.com/lib/weed-out-from # chmod 755 weed-out-from # mv weed-out-from /usr/bin
weed out a list from another list
