CODEWITHSUNDEEP
perl
nick
nick

Reputation: 11

How can I write a Perl script that generates a new log file each time it's run?

I am trying to modify a Perl script to create a different/new log file each time I run the script. I was trying to create each log file by date, but I am having trouble incorporating this concept... This is what I have so far:

#!perl -w

use WWW::Mechanize;

# What URL shall we retrieve?
$url = "http://www.mediabase.com/whatsong/whatsong.asp?var_s=075068071069045070077";

# Create a new instance of WWW::Mechanize
# enabling autocheck checks each request to ensure it was successful,
# producing an error if not.
my $mechanize = WWW::Mechanize->new(autocheck => 1);

# Retrieve the page
$mechanize->get($url);

# Assign the page content to $page
my $page = $mechanize->content;

# Output the page
#print $page;

# Let's also save the page locally
open LOG, ">>", "102.1_content.txt";

#print LOG $page; #######get error here when run from c++....

close(LOG);
########################################
########################################
# INPUT_FILE
open INPUT_FILE, "<", "102.1_content.txt";
########################################
my $html = join '', <INPUT_FILE>;

my @stuff = $html =~ />([^<]+)</g;
########################################

use Time::localtime;
$tm = localtime;
print "*****", $tm->mon+1, "/", $tm->mday, "/", 
      $tm->year+1900, "--", $tm->hour, "::", 
      $tm->min, "::", $tm->sec, 
      "******************************";
##sec, min, hour, mday, mon, year, wday, yday, and isdst
########################################
# OUTPUT_FILE
open OUTPUT_FILE, ">>", ("PLAYLIST_TABLE_"$tm->mon+1, "/", $tm->mday, "/", tm->year+1900".txt") or die $!;
########################################
print OUTPUT_FILE "******************************", 
            $tm->mon+1, "/", $tm->mday, "/", $tm->year+1900, 
            "--", $tm->hour, "::", $tm->min, "::", $tm->sec, 
            "******************************");

print join ("   ", @stuff), "\n";

print OUTPUT_FILE join ("           ", @stuff), "\n";

print "thats all!\n";

close(INPUT_FILE);
close(OUTPUT_FILE);

I apologize, I know my code is messy, and thanks in advance...

Nick

Upvotes: 1

Views: 6401

Answers (4)

Trudge
Trudge

Reputation: 57

I use a BEGIN block:

BEGIN
{
    open (STDERR,"> $0.txt");
    print STDERR scalar localtime, "\n";
}

The $0 is the name of the current script. So I add '.txt' so it's always easy to find. And the single redirect '>' ensures it doesn't grow if you forget about it. Just use '>>' if you want to append. Apache (or whatever server you run) saves log files as well, but they are all in the same file.

Upvotes: 0

yo.
yo.

Reputation: 11

You're forgetting to do error checking, so

use autodie;

We should all prefer a ISO8601 formatted date/time stamp :)

#!/usr/bin/perl --

use strict;
use warnings;

use File::Spec;
use POSIX();

my $thisf = File::Spec->rel2abs(__FILE__);
my $thisl = sprintf '%s-log-%s.txt', $thisf, POSIX::strftime(q!%Y-%m-%d-%H.%M.%SZ!,gmtime);

print "
thisf $thisf
thisl $thisl
";

__END__

$ perl tmp.pl

thisf /home/boy/tmp.pl
thisl /home/boy/tmp.pl-log-2009-11-08-20.35.38Z.txt

$

Upvotes: 0

Steve Schnepp
Steve Schnepp

Reputation: 4680

You should use . (dot) to concatenate strings. Here for the filename string it becomes :

open (OUTPUT_FILE, ">> PLAYLIST_TABLE_" . ($tm->mon+1) .  "/" . $tm->mday . "/" . ($tm->year+1900) . ".txt") or die $!;

The , (comma) works only with print AFAIK, and only because the usual transformation of an array in string is concatenation for print.

Upvotes: 2

Sinan &#220;n&#252;r
Sinan &#220;n&#252;r

Reputation: 118128

Use File::Spec or Path::Class to manipulate file names and paths:

#!/usr/bin/perl

use strict;
use warnings;

use File::Spec::Functions qw( catfile );

my ($mday, $mon, $year) = (localtime)[3 .. 5];

my $filename = catfile(
    sprintf('PLAYLIST_TABLE_%02d', $mon + 1),
    sprintf('%02d', $mday),
    sprintf('%04d.txt', $year + 1900)
);

print $filename, "\n";

Output (on Windows):

PLAYLIST_TABLE_11\06\2009.txt

However, I would recommend you use:

my $filename = catfile(
    sprintf('%04d.txt', $year + 1900)
    sprintf('PLAYLIST_TABLE_%02d', $mon + 1),
    sprintf('%02d', $mday),
);

so log files from runs close in time remain 'close' in the file system.

Please avoid having really long lines of string concatenations. They make it really hard to see what is going on an hide syntax errors in clutter. Instead, you could use join:

join('/', 
    "PLAYLIST_TABLE_" . ($tm->mon + 1),
    $tm->mday,
    ($tm->year + 1900) . '.txt'
);

Upvotes: 4

Related Questions