How do you read stdin using command-line PHP?

ppowell

Consider this:

The user is running "install.php" and is going to be prompted to enter a value in the terminal window like this:

Do you want to generate docs using PHPDocumentor (Y/N Enter = N)?

Bluntly put, how do I do this in PHP? I can't find any online resource that tells me how to prompt user to enter a value that will go into stdin using command-line PHP.

Thanx
Phil

crimaniak

fopen("php://stdin","r")

http://www.php.net/manual/en/wrappers.php.php

ppowell

Ok, maybe I'm just plain clueless (wouldn't surprise me), but I am not getting this.

// STEP 3: GENERATE PHP DOCS IF SUPPORT FOR phpDocumentor IS FOUND
   if ($hasPHPDocumentor) {
    echo "Do you want to generate docs as defined using $phpDocumentorPath? (y/n Enter = n)";
    ob_start();
     readfile('php://stdin', 'r');
     $response = ob_get_contents();
    ob_end_clean();
    if (strcmp(strtolower($response), 'y') == 0) generateDocs();
   }

This does not work as expected. If you enter anything it will never exit the program.

I'm trying to have it so that if you enter 'y' then it does generateDocs(), if not, it exits.

Phil

ppowell

In TCL it would be written this way:

puts {Do you want to do this (Y/N Enter=N)?}
gets stdin deleteChar

I guess what I need is the PHP equivalent of TCL's gets command (see http://www.astro.princeton.edu/~rhl/Tcl-Tk_docs/tcl8.0a1/gets.n.html for more information)

or perhaps the PHP equivalent of how a Java app would read from standard in:

BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
while ((in.readLine() == null)) {}

I checked out the PHP streaming capabilities and I have no clue how to use them and the manual makes no clear mention of how they can be used to retrieve from stdin:

http://www.php.net/wrappers.php

Help appreciated, this is driving me nuts!

Thanx
Phil

ahundiak

<?php
echo 'The Prompt: ';
$fp = fopen('php://stdin','r');
$input = fgets($fp);
fclose($fp);
$len = strlen($input);
echo "$input $len\n";
?>

ppowell

I wound up earlier coming up with this and wonder how it might compare from a memory allocation perspective to what you wrote:

 if ($hasPHPDocumentor) {
    echo "Do you want to generate docs as defined using $phpDocumentorPath? (y/n Enter = n)";
    $responseID = @fopen('php://stdin', 'r') or die('Cannot read stdin');								// READ FROM STANDARD INPUT
    while (($response = @fgets($responseID, 1024)) !== false) {										// RETRIEVE A VALUE ONCE ENTERED OR WAIT
     if (strcmp(strtolower(trim($response)), 'y') == 0) generateDocs();
     if ($response) {																			// CLOSE STREAM AND EXIT NO MATTER WHAT
      @fclose($responseID);
      exit();
     }
    }
    @fclose($responseID);
   }

Thanx
Phil

ahundiak

Life is way too short to worry about memory allocation for a variable read from stdin. But you could use strcasecmp if you wanted.

ppowell

Would love to have that luxury, but I work for a government contractor.. there are no "cutting corners" here. Everything has to be secure and tight especially in the open source world the US Government still does not "trust".

Phil