Log Script Use
How many old, unused (or under-used) CGI scripts do you
have lingering on your server, taking up space?
You may not be as guilty of abandoning CGI software in
lieu of newer versions as we are (we've been creating, and
testing software on the same server for 8 years) but odds
are you've got a few dusty, unused scripts lurking about.
The question we run into is "Are we using this script for
anything, and if we remove it, will it leave some form or
other function adrift or broken?"
Thus today's copy and paste code to log script use was
written. We share it with you.
The are a number of good reasons for knowing when your
CGI scripts are used on your server. It can help identify
script hijacking attempts. You can know what is abandoned
and what is attached to which form on what page. And you
will be likely to notice what scripts need upgrading, too.
The copy 'n paste code can be inserted into most Perl
scripts, causing the scripts to append a record of
information to a log file every time they run.
First, here is the copy 'n paste code. Then, I'll talk
about it.
{ my $file = "file.txt";
my @time = localtime;
$time[4]++;
$time[5] += 1900;
open Wlog,">$file" unless open Wlog,">>$file";
print Wlog "Year: $time[5] ";
print Wlog "Month: $time[4] ";
print Wlog "Day: $time[3] ";
print Wlog "Time: $time[2]:$time[1]:$time[0]";
print Wlog " — IP: $ENV{REMOTE_ADDR}";
print Wlog " — Referrer: $ENV{REFERER}";
print Wlog " — Self: $0\n";
close Wlog; }
Note that the first line of the code begins with an opening
curly brace character, and that the last line of the code
ends with a closing curly brace character. This has the
effect of isolating the code's variables from the variables
in the rest of the script, negating the chance of variable
name clashes.
Adding the code to your existing CGI scripts:
Always make a backup copy of any script before modifying it.
Putting the copy 'n paste code immediately below the first
line of the file should work for most scripts.
As usual, do all Perl script edits with a plain text word
processor like NotePad or TextWrangler. FTP file transfers
must likewise be as plain text.
Once the modified script has been uploaded, run it to verify
the log file is created.
If no log file is created when the script runs, your server
might not allow CGI scripts to create files in the directory
where the script is running. In that case:
-
Create a subdirectory for the log file, giving it
correct permissions. (Try 755 first, then 766, and
finally 777.)
-
Change the first line of the copy 'n paste code,
replacing "file.txt" with the subdirectory name
and the file name. Example: "log/file.txt"
The script should now create a log file (providing
the subdirectory permissions are correct.)
When the script runs, it tries to open the log file. If
unsuccessful, it creates the file.
Next, it grabs the server time and adjusts the month and
year numbers.
Then, it appends a record to the file, one line per record.
The year, month, day, and clock time are first in the
record. Next, the IP address, referrer (if available), and
the location of the script itself.
Last, the file is closed.
The referrer information can help identify the form(s) that
use the script. Not all browsers will provide referrer
information, but many will.
When you view the log file with your FTP program, the file's
date and time will let you know the last time the script
was used.
Opening the file will provide you with a record of each
script launch.
Question:
Did you find this article interesting and understandable? How can it be improved?
Your response is anonymous.
When done typing, click anywhere outside the box. [more info]
Will Bontrager
©2005 Bontrager Connection, LLC
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