Edit Report a Bug

    Ein- und Ausgabestreams

    Die CLI SAPI definiert einige Konstanten für Ein- und Ausgabestreams, um das Erstellen von Kommandozeilenanwendungen zu erleichtern.

    CLI-spezifische Konstanten
    Konstante Beschreibung
    STDIN

    Ein schon geöffneter Stream auf stdin. Dies erspart das Öffnen mit

    <?php
    $stdin     = fopen('php://stdin', 'r');
    ?>
    Wenn sie einzelne Zeilen von stdin lesen wollen, können Sie folgendes Code-Fragment verwenden:
    <?php
    $line     = trim(fgets(STDIN)); // liest eine Zeile von STDIN
    fscanf(STDIN, "%d\n", $number); // liest eine Zahl von STDIN
    ?>
    STDOUT

    Ein schon geöffneter Stream auf stdout. Das erspart das Öffnen mit

    <?php
    $stdout     = fopen('php://stdout', 'w');
    ?>
    STDERR

    Ein schon geöffneter Stream auf stderr. Das erspart das Öffnen mit

    <?php
    $stderr     = fopen('php://stderr', 'w');
    ?>

    Angesichts des oben Genannten, brauchen Sie beispielsweise nicht selbst einen Stream für stderr öffnen, sondern können einfach die Konstante anstelle der Ressource verwenden: 

    php -r 'fwrite(STDERR, "stderr\n");'
    Sie brauchen diese Streams nicht explizit zu schließen, weil sie automatisch von PHP geschlossen werden, wenn Ihr Skript endet.

    Hinweis:

    Diese Konstanten sind nicht verfügbar, wenn ein PHP Skript von stdin eingelesen wird.

    add a note add a note

    User Contributed Notes 5 notes

    up
    33
    Aurelien Marchand
    13 years ago
    Please remember in multi-process applications (which are best suited under CLI), that I/O operations often will BLOCK signals from being processed.

    For instance, if you have a parent waiting on fread(STDIN), it won't handle SIGCHLD, even if you defined a signal handler for it, until after the call to fread has returned.

    Your solution in this case is to wait on stream_select() to find out whether reading will block. Waiting on stream_select(), critically, does NOT BLOCK signals from being processed.

    Aurelien
    up
    7
    phil_php at zieaon dot com
    4 years ago
    Under Linux CLI - STDIN, STDOUT and STDERR can be closed and reconnected to a different php stream such as a file, pipe or even a UDP socket_stream. (I use this technique to send the output/errors of my long running background scripts to a file so I can debug if something goes wrong.)

    For example: (The below creates/appends file "/tmp/php_stdout.txt")
    <?php
    // This only works under CLI in Linux
    // Note: Until we have closed it STDOUT will NOT be prefixed with a $

    // Get the path to the current console for STDOUT so we can reconnect later!
            $strOldSTDOUT=(posix_ttyname(STDOUT)); 

        echo(    "This will go to the current console\r\n");
    // Close the STDOUT resource     
            fclose(STDOUT);   

    // Reopen $STDOUT as a file     Note: All further $STDOUT usage will be prefixed with a $
            $STDOUT=fopen("/tmp/php_stdout.txt","a");  /
        echo(    "This should append the file /tmp/php_stdout.txt\r\n");
    // Close stdout again so we can reconnect the console. Note: We are still using
            fclose($STDOUT);   

    // Use the path to the console we got earlier   
            $STDOUT=fopen($strOldSTDOUT,"r+");
        echo(    "And we are back on the console\r\n");

    ?>
    up
    20
    phil_php at zieaon dot com
    6 years ago
    The command line interface data in STDIN is not made available until return is pressed.
    By adding "readline_callback_handler_install('', function(){});" before reading STDIN for the first time single key presses can be captured.

    Note: This only seems to work under Linux CLI and will not work in Apache or Windows CLI.

    This cam be used to obscure a password or used with 'stream_select' to make a non blocking keyboard monitor.

    <?php

    // Demo WITHOUT readline_callback_handler_install('', function(){});
            $resSTDIN=fopen("php://stdin","r");
        echo(    "Type 'x'. Then press return.");
            $strChar = stream_get_contents($resSTDIN, 1);

        echo(    "\nYou typed: ".$strChar."\n\n");
            fclose($resSTDIN);
       
    // Demo WITH readline_callback_handler_install('', function(){});
    // This line removes the wait for <CR> on STDIN
            readline_callback_handler_install('', function(){});
       
            $resSTDIN=fopen("php://stdin","r");
        echo(    "We have now run: readline_callback_handler_install('', function(){});\n");
        echo(    "Press the 'y' key");
            $strChar = stream_get_contents($resSTDIN, 1);
        echo(    "\nYou pressed: ".$strChar."\nBut did not have to press <cr>\n");
            fclose($resSTDIN);
            readline_callback_handler_remove ();
        echo(    "\nGoodbye\n")
    ?>

    It also hides text from the CLI so can be used for things like. password obscurification.
    eg

    <?php
        readline_callback_handler_install    ('', function(){});
        echo(    "Enter password followed by return. (Do not use a real one!)\n");
        echo(    "Password: ");
            $strObscured='';
        while(    true)
        {
            $strChar = stream_get_contents(STDIN, 1);
        if(    $strChar===chr(10))
        {
            break;
        }
            $strObscured.=$strChar;
        echo(    "*");
        }
        echo(    "\n");
        echo(    "You entered: ".$strObscured."\n");
    ?>
    up
    12
    ecrist at secure-computing dot net
    13 years ago
    The following code shows how to test for input on STDIN.  In this case, we were looking for CSV data, so we use fgetcsv to read STDIN, if it creates an array, we assume CVS input on STDIN, if no array was created, we assume there's no input from STDIN, and look, later, to an argument with a CSV file name.

    Note, without the stream_set_blocking() call, fgetcsv() hangs on STDIN, awaiting input from the user, which isn't useful as we're looking for a piped file. If it isn't here already, it isn't going to be.

    <?php
    stream_set_blocking    (STDIN, 0);
    $csv_ar = fgetcsv(STDIN);
    if (    is_array($csv_ar)){
      print     "CVS on STDIN\n";
    } else {
      print     "Look to ARGV for CSV file name.\n";
    }
    ?>
    up
    -7
    ayon at hyurl dot com
    7 years ago
    I find a BUG with the constant STDIN, I don't know if it si the Enter/Return key that make this proprem, when I use trim(fgets(STDIN)), that doesn't trim anything, when I detect the length of fgets(STDIN), in windows, it is 2 characters longer than what I input, in Linux, it makes 1. I tried to trim(fgets(STDIN), ' \r\n'), but it still does not work.
    So I have to substr the input manually, it seems like this way:
    <?php
    $STDIN     = trim(substr(fgets(STDIN), 0, (PHP_OS == 'WINNT' ? 2 : 1)));
    ?>
    then I get what I want really.
    add a note add a note
    To Top