Category: General IT Info

PERL – How to Send Email

Here is a snippet of PERL code which you can use to send emails from your PERL scripts:

open (MAIL, "|/usr/sbin/sendmail -t ");
print MAIL "From: someFromAddress\@someFromDomain\n";
print MAIL "To: someToAddress\@someToDomain\n";
print MAIL "Content-Type: text/plain\n";
print MAIL "Subject: Very simple email test\n\n";
print MAIL "Body of the message";
close (MAIL);

Replace “someFromAddress\@someFromDomain” with an email address to be displayed in the “from” field of the email. It is important to not omit the backslash in front of the @ character in the email address. Similarly, replace “someToAddress\@someToDomain” with the email address to send the email to. Again don’t forget to escape the @ character in the email address by placing a backslash (\) in front of the @ sign. Also you’ll need to not leave off the “\n” you see in the to, from, and subject lines in the code.

Code

MySQL – How to Create an Admin User Account

If you want to create an additional admin account for MySQL server, connect to the MySQL server with a MySQL client program and execute the following command:

GRANT ALL ON *.* TO 'admin'@'localhost' IDENTIFIED BY 'password' WITH GRANT OPTION;

Change the word “admin” to whatever username you want to use for the admin account and change “password” to whatever password you want to use for that account.

The above SQL command creates an admin account that can only connect from the server which is running the MySQL database service. If you want to allow the admin account to log in from any IP address then replace “localhost” with “%”. The “%” acts as a wild card character.

GRANT ALL ON *.* TO 'admin'@'%' IDENTIFIED BY 'password' WITH GRANT OPTION;

If you want to only allow the admin account to log in from a specific IP or range of IPs then use the wildcard character:

GRANT ALL ON *.* TO 'admin'@'192.168.1.%' IDENTIFIED BY 'password' WITH GRANT OPTION;

The above example allows the admin account to log in from any IP address that starts with 192.168.1.

MySQL logo

PERL – How to Get the File Path For The Running PERL Script

Here is some sample code for determining what the file path is to the PERL script containing the code:

use Cwd qw(realpath);
my $fullpath = realpath($0);

If you just do $0 alone in the second line, that only gives you the filename that was executed. For example, if you include the first line of code above in a PERL script file named “perl foo.pl” $0 will return “foo.pl”. But if you ran the PERL script using an absolute path like this “perl /user/local/foo.pl”, $0 would return “/user/local/foo.pl”. So the example above uses the realpath() function to guarantee the full absolute path is always returned.

Code

OS X – How to Search For a Substring Inside of GZIP and BZ2 Files

This tip is really a generic *Nix command so it should not only work in OS X but also in other flavors of UNIX such as Linux.

In OS X a lot of the log files are auto-archived into compressed GZIP files in Tiger (Mac OS X 10.4) and BZ2 files in Leopard (Mac OS X 10.5). If you need to search for an occurrence of a word or other string of text in a compressed GZIP file, you can use the following terminal command:

zgrep someString theLogFileName.log.gz

As an example, say you want to search for the word “error” in a compressed system log in Tiger. To do this you would launch the Terminal application and run the command:

zgrep error /var/log/system.log.0.gz

Alternatively you can search all compressed system log files in a single command by using an asterisk (*) as a “wild card” character:

zgrep error /var/log/system.log*

Leopard uses the BZ2 compression scheme for most of its log files and you can similarly search those files by using the bzgrep command. For example, say you wanted to search all the application firewall logs for instances of the word “connection”. To do this you would run the following command in the Terminal application:

bzgrep connection /var/log/appfirewall.log*

If you need to search for a string that consists of more than one word separated by spaces, you would need to surround the search string in quotation marks:

bzgrep "connection attempt" /var/log/appfirewall.log*

Sherlock