[SOLVED] Optimize prefix checks of lines while iterating through file

Optimize prefix checks of lines while iterating through file

I'm writing a script in the form

while read LINE 
do
    [[ $LINE =~ ^headertag1 ]] && function1 && continue
    [[ $LINE =~ ^headertag2 ]] && function2 && continue
    ...
done < filename

As the number of tags increase, I will be doing too many checks per line. I can trying sorting the common tags higher up, but I don't think it solves the fundamental issue. I'm not a software engineer. Are there programming concepts/methods that can improve this situation?

Solution

Not sure here, but if you look for tidying up your code and feel bored by adding these if guards repetitively, then maybe this idea will help:

#!/bin/bash

tags[tag1]="some regex1"
tags[tag2]="some regex2"
tags[tag3]="some regex3"

function action() {
  echo "perl -pe '${tags[$tag]} other-file.txt'"
}

while read LINE; do
  for tag in "${!tags[@]}"; do
    [[ $LINE =~ ^$tag ]] && action "${tags[$tag]}"
  done
done < filename

Not sure if the OP is asking something like this.