How to read multiple files from a directory, extract specific strings and ouput to an html file? - perl

Question

Greetings,
I have the following code and am stuck on how I would proceed to modify it so it will ask for the directory, read all files in the directory, then extract specific strings and ouput to an html file? Thanks in advance.
#!/usr/local/bin/perl
use warnings;
use strict;
use Cwd;
print "Enter filename: "; # Should be Enter directory
my $perlfile =STDIN;
open INPUT_FILE, $perlfile || die "Could not open file: $!";
open OUTPUT, '>out.html' || die "Could not open file: $!";
# Evaluates the file and imports it into an array.
my #comment_array = ;
close(INPUT_FILE);
chomp #comment_array;
#comment_array = grep /^\s*#/g, #comment_array;
my $comment;
foreach $comment (#comment_array) {
$comment =~ /####/; #Pattern match to grab only #s
# Prints comments to screen
Print results in html format
# Writes comments to output.html
Writes results to html file
}
close (OUTPUT);

Answer 1

Take it one step at a time. You have a lot planned, but so far you haven't even changed your prompt string to ask for a directory.
To read the entered directory name, your:
my $perlfile =STDIN;
gives an error (under use strict;). Start by looking that error up (use diagnostics; automates this) and trying to figure out what you should be doing instead.
Once you can prompt for a directory name and print it out, then add code to open the directory and read the directory. Directories can be opened and read with opendir and readdir. Make sure you can read the directory and print out the filenames before going on to the next step.

Answer 2

a good starting point to learn about specific functions (from the cmd line)
perldoc -f opendir
However, your particular problem is answered as follows, you can also use command line programs and pipe them into a string to simplify file handling ('cat') and pattern matching ('grep').
#!/usr/bin/perl -w
use strict;
my $dir = "/tmp";
my $dh;
my #patterns;
my $file;
opendir($dh,$dir);
while ($file = readdir($dh)){
if (-f "$dir/$file"){
my $string = `cat $dir/$file | grep pattern123`;
push #patterns, $string;
}
}
closedir($dh);
my $html = join("<br>",#patterns);
open F, ">out.html";
print F $html;
close F;