I need a script that searches files for SSI and replaces the include with the actual HTML

Question 1

The specification does not cover every details, so I have the following assumptions.

The  line stays its own. Other characters are removed.
Included files does not contains additional includes.
In project directory no subdirs has to be checked.

In this case something like this can do the job. It is in bash:

#!/usr/bin/bash

search=${1:-./}

replace() {
  while read -r x; do
    if [[ "$x" =~ \<!--#include\ file=\"([^\.]+.html)\"--\> ]]; then
      cat "${BASH_REMATCH[1]}";
    else
      echo "$x"
    fi
  done <"$1"
}

while read f; do
  replace "$f" > tmp_$$.tmp && mv tmp_$$.tmp "$f"
done < <(find $search  -maxdepth 1 -name '*.html')

It reads all the *.html files in the specified directory (not recursively). If no args given it checks the current directory. For each line it calls replace function. Replace searches for include lines. If one found, then prints the content of the file to the stdout, otherwise the original line is presented.

Lets consider to files:

cat >master.html <<XXX
<html>
<!--#include file="myfile.html"-->
</html>
XXX

cat >myfile.html <<XXX
<title>
My file
</title>
XXX

Result:

$ cat master.html
<html>
<title>
My file
</title>
</html>
$ cat myfile.html
<title>
My file
</title>

I hope this could help...

Question 2

On your dev machine, use your browser to display the web page, and then save the 'result' with an appropriate file name/in an output directory.

Thus, if you had mainfile.html which executed various time/last-mod directives and which included fileA.inc and fileB.inc at appropriate places, the resulting display (and save-able HTML file) will comprise all four/five components.

=dn

I need a script that searches files for SSI and replaces the include with the actual HTML

EDIT