awk pattern search with file input to search in another file

Question

I am looking for some hints, how I could achive a better, more elegant, efficient solution. So I've got a file containing a list of names.

names.txt:

Doe John
del Super Mario
van Hoppity Jenny
van der Hupfburg Susi
Smith-Osborne John Marc

Desired Output:

John Doe
Mario del Super
Jenny van Happity
Susi van der Hupfburg
John Marc Smith-Osborne

As you can see, the sort order is "family name" followed by "name" and no specific delimiter (just spaces) seperating family name from name. What I want is first name than family name. In most cases the first word is the family name. In some cases, there is a prefix like "van" or the italian "del". To attach these prefixex to the family name, I want to replace the spaces with a dash - so they become on word (van-Hoppity, van-der-Hupfburg, etc.) and i can move the first word to the end of line,

My current sed solution is working, but the line is getting longer and longer with every new prefix found.

So i want to use awk, with a file containing the search patterns (prefix list) that should find the pattern in the names file and replace it.

so 2 files

• names.txt
• pattern.txt

pattern.txt containing the prefixes and the substitute replacement in the second field. Field seperator is ";"

pattern.txt:

 del ;del-
 van der ;van-der-
 van ;van-

awk should use pattern.txt to search in names.txt and replace the found matches with the value of field 2 in pattern.txt

Any idea hints, suggestions?

Answer 1

As far as I can see your text file (which is a horrible way to store such data) can be interpreted as:

• each line contains a name
• the family name, surname may start with a all-lower-case prefix of zero or more words (e.g. "van" , "del", "van der") followed by a capitalised word
  Implied: the list doesn't contain entries like "Von Doom Victor"
• separated with a space from:
• one or more first names

On possible regular expression to make a capture group of your (family Name) <space> (First Name(s)) is (^[^A-Z]*[A-Z][^ ]*) (.*$).

The regex I'm using is explained here: https://regex101.com/r/kOjwiS/1

and poured into a bash snippet :

#!/bin/bash 
regex="(^[^A-Z]*[A-Z][^ ]*) (.*$)" 
while read line ; do  
  [[ "$line" =~ $regex ]]
  echo "Firstname(s): ${BASH_REMATCH[2]}" 
  echo  "Family Name: ${BASH_REMATCH[1]}" 
done < names.txt

Firstname(s): John
Family Name: Doe
Firstname(s): Mario
Family Name: del Super
Firstname(s): Jenny
Family Name: van Hoppity
Firstname(s): Susi
Family Name: van der Hupfburg
Firstname(s): John Marc
Family Name: Smith-Osborne