PHP Cookbook

18.18. Writing to Standard Output

Problem

You want to write to standard output.

Solution

Use echo or print:

print "Where did my pastrami sandwich go?";
echo  "It went into my stomach.";

Discussion

While print( ) is a function, echo is a language construct. This means that print( ) returns a value, while echo doesn’t. You can include print( ) but not echo in larger expressions:

// this is OK
(12 == $status) ? print 'Status is good' : error_log('Problem with status!');

// this gives a parse error
(12 == $status) ? echo 'Status is good' : error_log('Problem with status!');

Use php://stdout as the filename if you’re using the file functions:

$fh = fopen('php://stdout','w') or die($php_errormsg);

Writing to standard output via a file handle instead of simply with print( ) or echo is useful if you need to abstract where your output goes, or if you need to print to standard output at the same time as writing to a file. See Section 18.20 for details.

You can also write to standard error by opening php://stderr:

$fh = fopen('php://stderr','w');

See Also

Section 18.20 for writing to many filehandles simultaneously; documentation on echo at http://www.php.net/echo and on print( ) at http://www.php.net/print.