Often we (php developers) need to log certain messages in order to debug our script. Here I will describe the default syslog method and a much simpler (and better) way to log your messages quickly and painlessly.

PHP manual suggests using syslog for logging.

Problems with syslog
The problem with syslog is that its implementation is system dependent. For example openlog() is not supported on windows.

The location of the logged data is system dependent, which you may not have access to (if you are on a shared web hosting environment) or know about.

The procedure is more cumbersome than you may like to undertake for simple quick and dirty log messages.

Using syslog
Here is a sample code using syslog:

< ?php
define_syslog_variables();
// open syslog, include the process ID and also send
// the log to standard error, and use a user defined
// logging mechanism
openlog("myScriptLog", LOG_PID | LOG_PERROR, LOG_LOCAL0);

// some code

if (authorized_client()) {
// do something
} else {
// unauthorized client!
// log the attempt
$access = date("Y/m/d H:i:s");
syslog(LOG_WARNING, "Unauthorized client: $access $_SERVER[REMOTE_ADDR] ($_SERVER[HTTP_USER_AGENT])");
}

closelog();
?>

Simpler alternative
Now lets look into a quicker and simpler alternative for your simple logging needs.
file_put_contents('log_file_name', $data, FILE_APPEND);

$data is the data you want logged. You can also pass in an array. This creates a file in the directory the script is invoked from and appends your log messages.