How would a date in HTML file using a .bat script - html

Question

I have a .html file titlepage.html that contains the following line:
<span class="titlepage modified">Modified: Feb 13, 2020 </span>
The problem is, that sometimes I forget to change the "Modified: " date
I run a .bat file which moves this titlepage.html to the proper location, so I figured it would make sense to add a subroutine in the .bat file to update the date before moving it.
my current .bat file looks like:
#echo off
setlocal enabledelayedexpansion
set infile=titlepage.html
set outfile=result.html
Set find=Modified:
set replace="<span class="titlepage modified">Modified: %DATE% </span>"
del result.html
for /F "tokens=1,2 delims=" %%n in (!infile!) do (
set LINE=%%n
set TMPR=!LINE:%find%=%replace%!
echo !TMPR!>>%outfile%
)
And the line in question of my looks like:
<span class="titlepage modified">"<span class="titlepage modified">Modified: 04/10/20 </span>" Feb 13, 2020 </span>
So it successfully inputs the information I want, but I need it to replace the entire line in question not just the part I used for the lookup.
*Note the dates will be arbitrary so I can't perform a lookup on the entire line.
So I want to:
1. Lookup for a line containing a string
2. Replace that entire line with my new input.
Thanks in advance.

Answer 1

#echo off
setlocal enabledelayedexpansion
set "target=./titlepage.html"
set "destination=./titlepage.html"
set "find=(?mi)^.*Modified:.*$"
set "replace=<span class=\"titlepage modified\">Modified: %DATE% </span>"
powershell -noprofile -command^
$content=get-content -path '!target!';^
$result=$content -replace '!find!', '!replace!';^
set-content -path '!destination!' -value $result
powershell reads the the target ./titlepage.html, does the replacement and writes to the destination ./titlepage.html.
The regular expression pattern searches for Modified: in a line. The find variable contains the pattern and uses options (?mi). The m is multiline mode and the i is case insensitive. If you want case insensitive, remove the i.
Regular expression pattern:
(?mi) Regular expression options. m is multiline and i is case insensitive.
^ By default, the match must start at the beginning of the string; in multiline mode, it must start at the beginning of the line.
. Wildcard: Matches any single character except \n.
* Matches the previous element zero or more times.
$ By default, the match must occur at the end of the string or before \n at the end of the string; in multiline mode, it must occur before the end of the line or before \n at the end of the line.
Replacement string:
\" Escape nested double quote for command line parsing to powershell.
View the Regular Expression Language - Quick Reference for more information.
The ^ at the end of lines, of the powershell command, are line continuations.