Using ARGV When Recursing through Directories in Perl - perl

Question

What I am trying to do is get my program to recurse through a directory and for all of those files within the directory, search each file for the word "ERROR" and then print the instance of it out in a seperate file. I was able to do this without making it recursive, i.e. just entering which files to check manually in the cmd. I was wondering what the proper way to use ARGV when recursing is. Here is my code thus far:
#!/usr/bin/perl
use strict;
use warnings;
use File::Find;
my $dir = "c:/programs";
find(\&searchForErrors, $dir);
sub searchForErrors()
{
my $seen = 0;
if (-f){
my $file = $_;
my #errors = ();
open FILE, $file;
my #lines = <FILE>;
close FILE;
for my $line (#lines){
if (/ERROR/ ){
push(#errors, "ERROR in line $.\n");
print FILE "ERROR in line $.:$1\n" if (/Error\s+(.+)/);
}
open FILE, ">$file";
print FILE #lines;
close FILE;
}
}
}
What I need to know is how I can incorporate ARGV so that the program will read in each file in the directory, perform the search, and then output the results of the search to a file. I hope I have explained my question adequately, if you need any clarification, let me know what is confusing. The more explanation you can give with the answer, the better. Thank you!

Answer 1

ARGV is usually used to iterate over files provided from outside of Perl.
$ find -type f --exec perl script.pl {} +
# script.pl
while (<>) {
print "$ARGV:$.: $1\n" if /Error\s+(.+)/;
} continue {
close(ARGV) if eof; # Reset $.
}
But it's not necessary. You could also do:
use File::Find::Rule qw( );
#ARGV = File::Find::Rule->file->in('.');
while (<>) {
print "$ARGV:$.: $1\n" if /Error\s+(.+)/;
} continue {
close(ARGV) if eof; # Reset $.
}
I prefer File::Find::Rule, but you could stick with File::Find for reasons that should be obvious if you compare the above snippet with the following snippet:
use File::Find qw( find );
#ARGV = ();
find({ wanted => sub { push #ARGV, $_ if -f }, no_chdir => 1 }, '.');
while (<>) {
print "$ARGV:$.: $1\n" if /Error\s+(.+)/;
} continue {
close(ARGV) if eof; # Reset $.
}
PS - You're replacing each file with an exact copy of itself, and you're populating an array you never use. I omitted that code from my version.