#!/bin/bash

textfile="file.txt"
htmlfile="file.html"

rm "$htmlfile"
x=0

cat "$textfile" |sed 's/=/\n=\n/g'|while read line
do
    if [ "$line" = "=" ]
    then
      if [ "$x" = "0" ]
      then
        echo "<h1>" >> "$htmlfile"
        x=1
      else
        echo "</h1>" >> "$htmlfile"
        x=0
      fi
    else
      echo "$line" >> "$htmlfile"
    fi
done