Read from file into variable - Bash Script take2

Question

This is a second part of Read from file into variable - Bash Script

I have a bash script that reads strings in a file parses and assigns it to a variable. The file looks like this (file.txt):

database1 table1
database1 table4
database2
database3 table2

Using awk in the script:

s=$(awk '{$1=$1}1' OFS='.' ORS='|' file.txt)
LIST="${s%|}"

echo "$LIST"
database1.table1|database1.table4|database2|database3.table2 

But I need to add some wildcards at the end of each substring. I need this result:

database1.table1.*|database1.table4.*|database2*.*|database3.table2.*

The conditions are: if we read database2 the output should be database2*.* and if we read a database and a table the output should be database1.table1.*

Answer 1

Use this awk with ORS='.*|' :

s=$(awk '$0=="database2"{$0=$0 "*.*";print;next} {$2=$2 ".*"}1' OFS='.' ORS='|' file.txt)
LIST="${s%|}"

echo "$LIST"
database1.table1.*|database1.table4.*|database2*.*|database3.table2.*

Answer 2

Assuming the (slightly odd) regex is correct the following awk script works for me on your example input.

BEGIN {OFS="."; ORS="|"}
!$2 {$1=$1"*"}
{$(NF+1)="*"}
1

1. Set OFS and ORS .
2. If we do not have a second field add a * to our first field.
3. Add a * as a final field.
4. Print the line.

Run as awk -f script.awk inputfile where the above script is in the script.awk (or whatever) file.

Answer 3

I'd do it like this.

script.sh containing the following code:

#!/bin/bash

while IFS='' read -r line ;do
  database=$(awk '{print $1}' <<< $line)
     table=$(awk '{print $2}' <<< $line)
  if [ "${table}" == '' ] ;then
    list=(${list}\|${database}\*\.\*)
  else
    list=(${list}\|${database}\.${table}\.\*)
  fi
done <file.txt

list=$(cut -c 2- <<< ${list})
echo ${list}

exit 0

file.txt containing the following data:

database1 table1
database1 table4
database2
database3 table2

Script output is the following:

database1.table1.*|database1.table4.*|database2*.*|database3.table2.*

Tested in BASH version: GNU bash, version 5.0.17(1)-release (x86_64-pc-linux-gnu)