Use of undefined constant STDIN – assumed 'STDIN' in C:\wamp\www\study\sayHello.php on line 5

I want to Learn php & mySQL and I purchased a book (php&mySql: the missing manuals 2edition)

I installed Wampserver2.4 on win8 64bit machine.

Server Configuration

Apache Version : 2.4.4
PHP Version : 5.4.12

in first lesson i got this error ๐Ÿ™

Notice: Use of undefined constant STDIN - assumed 'STDIN' in C:\wamp\www\study\sayHello.php on line 5

this is the php code on file “sayHello.php”


echo "Hello there. So I hear you're learning to be a PHP programmer!\n";
echo "Why don't you type in your name for me:\n";
$name = trim(fgets(STDIN));

echo "\nThanks, " . $name . ", it's really nice to meet you.\n\n";


Here is Solutions:

We have many solutions to this problem, But we recommend you to use the first solution because it is tested & true solution that will 100% work for you.

Solution 1

Just define STDIN constant at top of your file,


Solution 2

when you are trying to run migration form a PHP file using


seems that’s time also produce these type of error.
For solve this problem you can simple replace your code with

Artisan::call(‘migrate’, [‘–force’ => true ])

Make sure you use –force flag if you are in production.

Solution 3


Only the CLI (command line) SAPI defines I/O constants such as STDIN, STDOUT, and STDERR, purely for convenience in that environment.


As stated in other answers, you can simply define these constants in your PHP code. You can also check defined() to avoid errors when invoked via CLI. For example:


if (!defined('STDIN')) {
  define('STDIN', fopen('php://stdin', 'r'));

However, keep in mind that php://stdin may not work the way you expect in a non-CLI SAPI, such as Apache or FPM. For example, to access the raw POST body when executed via FPM, you would use php://input instead.

More Info

PHP has many different SAPI (Server Application Programming Interface), that allow you to execute PHP code in various environments such as your Web server, email server, or the command line (CLI). Examples include:

  • CGI
  • FPM
  • Milter (email filters)
  • Apache
  • etc

Each SAPI may have slightly different initial conditions and behavior. Some other differences between the CLI SAPI and other SAPIs include:

  • header() has no effect.
  • Some ini settings such as html_errors and output_buffering have different default values (more appropriate for the CLI).
  • Does not change the current working directory (CWD) to the script you executed.

Solution 4

Try adding this on the top of your file


Solution 5

When this error comes from the Youtube Data API code sample, it is because the sample is designed to be run from a CLI and a browser-based implementation does not provide a means of prompting the user for input that is called for by that STDIN line.

Since the auth code is provided as a parameter in the $authUrl variable that gets printed to the screen the first time the script is run, I was able to resolve my issue by replacing

$authCode = trim(fgets(STDIN));


$authCode = $_GET['code'];

Solution 6

Sometimes you will change the ENV to production and tried to update in that ENV. So better change back that ENV to local. Change .env file.

Earlier: APP_ENV=production

Solution: APP_ENV=local

Solution 7

It looks like you are trying to use a constant called STDIN, which does not exist.

STDIN is used to get a currently open stream with fopen.

$file = fopen('file/path');

$name = trim(fgets(STDIN));

Using STDIN without a currently open stream would not work.

I also believe that STDIN only works under cli, but am not 100% sure. If that is the case, use the same code as above, but replace STDIN with $file;

Solution 8

If you want your code to be executed properly with the “STDIN” Constant you have two options:

# php -r "fgets(STDIN);"

or :

# gedit file.php //make a file with <?php fgets(STDIN); ?>
# php file.php // execute the file

The other option :

 //click on ctrl+d

Will not work !! you may have to define the “STDIN” constant inside your code as mentioned above.

Note: Use and implement solution 1 because this method fully tested our system.
Thank you ๐Ÿ™‚

All methods was sourced from or, is licensed under cc by-sa 2.5, cc by-sa 3.0 and cc by-sa 4.0

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