Expect Functions

Introducción

This extension allows to interact with processes through PTY. You may consider using the expect:// wrapper with the filesystem functions which provide a simpler and more intuitive interface.

Requisitos

This module uses the functions of the » expect library. You need libexpect version >= 5.43.0.

Instalación

Esta extension » PECL no esta ligada a PHP. Mas informacion sobre nuevos lanzamientos, descargas ficheros de fuentes, informacion sobre los responsables asi como un 'CHANGELOG', se puede encontrar aqui: » http://pecl.php.net/package/expect.

En PHP 4 la fuente de las extensiones PECL pueden encontrarse en el directorio ext/ que se existe en las fuentes de PHP o en el enlace PECL de arriba. In order to use these functions you must compile PHP with expect support by using the --with-expect[=DIR] configure option.

Windows users will enable php_expect.dll inside of php.ini in order to use these functions. En PHP 4, esta DLL se encuentra en el directorio extensions/ que existe en los binarios de PHP para Windows. Podeis descargar esta DLL de las extensiones PECL desde la pagina » PHP Downloads o desde » http://snaps.php.net/.

Configuración en tiempo de ejecución

El comportamiento de estas funciones está afectado por los valores definidos en php.ini.

In order to configure expect extension, there are configuration options in the configuration file php.ini.

**Expect Configure Options**
Name	Default	Changeable
expect.timeout	"10"	PHP_INI_ALL
expect.loguser	"1"	PHP_INI_ALL
expect.logfile	""	PHP_INI_ALL

For further details and definitions of the PHP_INI_* constants, see the Directivas de php.ini.

A continuación se presenta una corta explicación de las directivas de configuración.

expect.timeout integer

The timeout period for waiting for the data, when using the expect_expectl() function.

A value of "-1" disables a timeout from occurring.

Note: A value of "0" causes the expect_expectl() function to return immediately.

expect.loguser boolean

Whether expect should send any output from the spawned process to stdout. Since interactive programs typically echo their input, this usually suffices to show both sides of the conversation.

expect.logfile string

Name of the file, where the output from the spawned process will be written. If this file doesn't exist, it will be created.

Note: If this configuration is not empty, the output is written regardless of the value of expect.loguser.

Tipos de recursos

expect_popen() returns an open PTY stream used by expect_expectl().

Constantes predefinidas

Estas constantes están definidas por esta extensión y estarán disponibles solamente cuando la extensión ha sido o bien compilada dentro de PHP o grabada dinámicamente en tiempo de ejecución.

EXP_GLOB (integer): Indicates that the pattern is a glob-style string pattern.
EXP_EXACT (integer): Indicates that the pattern is an exact string.
EXP_REGEXP (integer): Indicates that the pattern is a regexp-style string pattern.
EXP_EOF (integer): Value, returned by expect_expectl(), when EOF is reached.
EXP_TIMEOUT (integer): Value, returned by expect_expectl() upon timeout of seconds, specified in value of expect.timeout
EXP_FULLBUFFER (integer): Value, returned by expect_expectl() if no pattern have been matched.

Ejemplos

This example connects to the remote host via SSH, and prints the remote uptime.

Example#1 Expect Usage Example


<?php
ini_set ("expect.loguser", "Off");

$stream = fopen ("expect://ssh root@remotehost uptime", "r");

$cases = array (
  array (0 => "password:", 1 => PASSWORD)
);

switch (expect_expectl ($stream, $cases)) {
 case PASSWORD:
  fwrite ($stream, "password\n");
  break;
 
 default:
  die ("Error was occurred while connecting to the remote host!\n");
}

while ($line = fgets ($stream)) {
  print $line;
}
fclose ($stream);
?>

The following example connects to the remote host, determines whether installed OS is for 32 or 64 bit, then runs update for specific package.

Example#2 Another Expect Usage Example


<?php
ini_set ("expect.timeout", -1);
ini_set ("expect.loguser", "Off");

$stream = expect_popen ("ssh root@remotehost");

while (true) {
    switch (expect_expectl ($stream, array (
            array ("password:", PASSWORD), // SSH is asking for password
            array ("yes/no)?", YESNO), // SSH is asking whether to store the host entry
            array ("~$ ", SHELL, EXP_EXACT), // We've got the shell!
    ))) {
        case PASSWORD:
            fwrite ($stream, "secret\n");
            break;

        case YESNO:
            fwrite ($stream, "yes\n");
            break;

        case SHELL:
            fwrite ($stream, "uname -a\n");
            while (true) {
                    switch (expect_expectl ($stream, array (
                            array ("~$ ", SHELL, EXP_EXACT), // We've got the shell!
                            array ("^Linux.*$", UNAME, EXP_REGEXP), // uname -a output
                    ), $match)) {
                        case UNAME:
                            $uname .= $match[0];
                            break;
                        
                        case SHELL:
                            // Run update:
                            if (strstr ($uname, "x86_64")) {
                                    fwrite ($stream, "rpm -Uhv http://mirrorsite/somepath/some_64bit.rpm\n");
                            } else {
                                    fwrite ($stream, "rpm -Uhv http://mirrorsite/somepath/some_32bit.rpm\n");
                            }
                            fwrite ($stream, "exit\n");
                            break 2;
                    
                        case EXP_TIMEOUT:
                        case EXP_EOF:
                            break 2;

                        default:
                            die ("Error has occurred!\n");
                    }
            }
            break 2;

        case EXP_TIMEOUT:
        case EXP_EOF:
            break 2;

        default:
            die ("Error has occurred!\n");
    }
}

fclose ($stream);
?>