Monthly Archives: June 2011

tail -F

Posted on June 30, 2011 by timwarnock

I would like to follow an error log as errors are written. The GNU tail command support a --follow option that outputs data as a file grows. There's also a --retry option that will keep trying to access a file … Continue reading →

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nohup &

Posted on June 30, 2011 by timwarnock

I would like to run a script in the background and to keep running even after I log out. To run a command or script in the background use an ampersand, e.g., # ./long-running-script.sh & This is equivalent to suspending … Continue reading →

Posted in bash, shell tips | Leave a comment

php echo and print

Posted on June 30, 2011 by timwarnock

Is echo really, even negligibly, faster than print in php? Conventional wisdom of the Internet says "yes", because print performs one extra op (it returns a value). I've seen performance charts with 20% or more difference in performance. I tested … Continue reading →

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get_magic_quotes_gpc(), or not

Posted on June 30, 2011 by timwarnock

I would like to sanitize user-supplied HTTP request variables before sending them to a database. There is a deprecated PHP setting called magic_quotes_gpc that automatically escapes GET, POST, and COOKIE (GPC) operators. Please understand that magic_quotes_gpc is highly discouraged. <?php … Continue reading →

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last_insert_id()

Posted on June 29, 2011 by timwarnock

I would like to retrieve the id of a row I just inserted. In Oracle this problem is handled with the use of sequences, SQL> SELECT uid_seq.NEXTVAL INTO user_id FROM DUAL; SQL> INSERT INTO users (id, username) VALUES (user_id, 'joebob'); … Continue reading →

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php DB adapter, with magic

Posted on June 29, 2011 by timwarnock

I would like to encapsulate the handling of database connections, and maintain a loose coupling between database connections and application and data-access code. I'll not focus on connection pooling since that can be handled at the driver level independent of … Continue reading →

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mysql \c

Posted on June 27, 2011 by timwarnock

The mysql command line interface provides several very useful shortcuts. For example, the 'tee' command will append everything to a specified outfile: mysql> \T logfile.txt Logging to file 'logfile.txt' The 'clear' command saves from accidentally hitting Ctrl-C and disconnecting from … Continue reading →

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php Namespaces and Class loading

Posted on June 26, 2011 by timwarnock

I want to autoload php classes and functions. Ideally, I want a lazy loader (include class files only when they are needed, never including more files than necessary). I'd also like namespace protection (if running PHP 5.3 or later). And … Continue reading →

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