shell bash replacing tags in a line with values from a different file

Question

I am trying to read lines within a file and if the line contains a tag, the text within the tag is used to replace the tag with a value from a different propertiesfile, before the line, with all tags replaced is written to a different file.

So the initial file being read have lines that would adhere to the following format:

testkey "TEST-KEY" "[#key_location#]:///[#key_name#]"

Where [# and #] house the tag text.

The propertied file would then contain lines like:

key_location=location_here
key_name=test_key_name

So the end result I am trying to achieve is that the line is written to a new file, but the tags are replaced with the values from the property file, so using the above content:

testkey "TEST-KEY" "loaction_here:///test_key_name"

I am not sure how best to handle the tags and deal with multiple tags in one line and am pretty lost. Any help would be greatly appreciated.

Skeleton code:

while read line

    if [[ $line == *[#* ]]
    then
       #echo found a tag and need to deal with it





    else

        echo "$line">> $NEW_FILE
    fi

   done < $INITIAL_FILE

EDIT

Lines within the file could contain one or more tags, not always two like in the example given.

Answer 1

You'll have to do some looping and global sed replacements. The following is probably not optimal but it will get you started:

#!/bin/bash

declare -A props
while read line ; do
    key=$(echo $line | sed -r 's/^(.*)=.*/\1/')
    value=$(echo $line | sed -r 's/^.*=(.*)/\1/')
    props[$key]=$value
done < values.properties

replace() {
    line=$1
    for key in "${!props[@]}"; do 
        line=$(echo $line | sed "s/\[#$key#\]/${props[$key]}/g")
    done
    echo $line
}

while read line ; do
    while [[ $line == *"[#"*"#]"* ]] ;do
        line=$(replace "$line")
        echo Iter: $line
    done
    echo DONE: $line
done < $INITIAL_FILE

The snippet prints to stdout and it includes intermediate results so that you can check how it works. I think you will easily be able to modify it to write to a file, etc.

Answer 2

There are a number of ways to do this (e.g. count #). But simply, you can just use * expansion outside just the start and end of the string so

if [[ $line == *"[#"*"#]"*"[#"*"#]"* ]]; then 
  echo "has tags"
else 
  echo "does not have tags" 
fi

Would work in your case, e.g.

$ echo "$line" 
testkey "TEST-KEY" "[#key_location#]:///[#key_name#]"
$ if [[ $line == *"[#"*"#]"*"[#"*"#]"* ]]; then echo "has tags"; fi
has tags