Make reference to a file in a regular expression - regex

Question

I have two files. One is a SALESORDERLIST, which goes like this
ProductID;ProductDesc
1,potatoes 1 kg.
2,tomatoes 2 k
3,bottles of whiskey 2 un.
4,bottles of beer 40 gal
(ProductID;ProductDesc) header is actually not in the file, so disregard it.
In another file, POSSIBLEUNITS, I have -you guessed- the possible units, and their equivalencies:
u;u.;un;un.;unit
k;k.;kg;kg.,kilograms
This is my first day with regular expressions and I would like to know how can I get the entries in SALESORDERLIST, whose units appear in POSSIBLEUNITS. In my example, I would like to exclude entry 4 since 'gal' is not listed in POSSIBLEUNITS file.
I say regex, since I have a further criteria that needs to be matched:
egrep "^[0-9]+;{1}[^; ][a-zA-Z ]+" SALESORDERLIST
From those resultant entries, I want to get those ending in valid units.
Thanks!

Answer 1

One way of achieving what you want is:
cat SALESORDERLIST | egrep "\b(u|u\.|un|un\.|unit|k|k\.|kg|kg\.|kilograms)\b"
1,potatoes 1 kg.
2,tomatoes 2 k
3,bottles of whiskey 2 un.
The metacharacter \b is an anchor that allows you to perform a "whole words only" search using
a regular expression in the form of \bword\b.
http://www.regular-expressions.info/wordboundaries.html

Answer 2

One way would be to create a bash script, say called findunit.sh:
while read line
do
match=$(egrep -E "^[0-9]+,{1}[^, ][a-zA-Z ]+" <<< $line)
name=${match##* }
# echo "$name..."
found=$(egrep "$name" /pathtofile/units.txt)
# echo "xxx$found"
[ -n "$found" ] && echo $line
done < $1
Then run with:
findunit.sh SALESORDERLIST
My output from this is:
1,potatoes 1 kg.
2,tomatoes 2 k
3,bottles of whiskey 2 un.

Answer 3

An example of doing it completely in bash:
declare -A units
while read line; do
while [ -n "$line" ]; do
i=`expr index $line ";"`
if [[ $i == 0 ]]; then
units[$line]=1
break
fi
units[${line:0:$((i-1))}]=1
line=${line#*;}
done
done < POSSIBLEUNITS
while read line; do
unit=${line##* }
if [[ ${units[$unit]} == 1 ]]; then
echo $line
fi
done < SALESORDERLIST