The Cmd:: class implements an abstraction for various ways

of executing commands (directly using the backtick operator,
as a background task after the script has terminated using
register_shutdown_function() or as a detached process using nohup).

1 files changed, 286 insertions, 0 deletions

diff --git a/pear/CMD.php b/pear/CMD.php
new file mode 100755
index 0000000000..b01f46c667
--- /dev/null
+++ b/pear/CMD.php
@@ -0,0 +1,286 @@
+<?php
+//
+// +----------------------------------------------------------------------+
+// | PHP version 4.0                                                      |
+// +----------------------------------------------------------------------+
+// | Copyright (c) 1997-2001 The PHP Group                                |
+// +----------------------------------------------------------------------+
+// | This source file is subject to version 2.02 of the PHP license,      |
+// | that is bundled with this package in the file LICENSE, and is        |
+// | available at through the world-wide-web at                           |
+// | http://www.php.net/license/2_02.txt.                                 |
+// | If you did not receive a copy of the PHP license and are unable to   |
+// | obtain it through the world-wide-web, please send a note to          |
+// | license@php.net so we can mail you a copy immediately.               |
+// +----------------------------------------------------------------------+
+// | Authors: Anders Johannsen <anders@johannsen.com>					  |
+// |                                                                      |
+// +----------------------------------------------------------------------+
+//
+define('CMD_RCSID', '$Id$');
+
+/**
+ * The Cmd:: class implements an abstraction for various ways 
+ * of executing commands (directly using the backtick operator,
+ * as a background task after the script has terminated using
+ * register_shutdown_function() or as a detached process using nohup).
+ *
+ * @author  Anders Johannsen <anders@johannsen.com>
+ * @version $Revision$
+ **/
+
+require_once 'PEAR.php';
+
+
+class Cmd extends PEAR
+{
+    var $arrSetting 	= array();
+    var $arrConstant 	= array();
+    var $arrCommand 	= array();
+		
+    /**
+     * Class constructor
+     * 
+     * Defines all necessary constants and sets defaults
+     * 
+     * @author Anders Johannsen <anders@johannsen.com>
+	 *
+     * @access public
+     * 
+     **/
+		
+    function Cmd ()
+    {
+		// Defining constants
+		$this->arrConstant 	= array ("CMD_SEQUENCE",
+						 			 "CMD_SHUTDOWN",
+						 			 "CMD_SHELL",
+						 			 "CMD_OUTPUT",
+						 			 "CMD_NOHUP",
+						 			 "CMD_VERBOSE"
+						 			 );
+				
+		foreach ($this->arrConstant as $key => $value) {
+		    if (!defined($value)) {
+				define($value, $key);
+		    }
+		}
+				
+		// Setting default values
+		$this->arrSetting[CMD_SEQUENCE]		= true; 
+		$this->arrSetting[CMD_SHUTDOWN]		= false; 
+		$this->arrSetting[CMD_OUTPUT]		= false; 
+		$this->arrSetting[CMD_NOHUP]		= false; 
+		$this->arrSetting[CMD_VERBOSE]		= false; 
+				
+		$arrShell = array ("sh", "bash", "zsh", "tcsh", "csh", "ash", "sash", "esh", "ksh");
+								   
+		foreach ($arrShell as $shell) {
+		    if ($this->arrSetting[CMD_SHELL] = $this->which($shell)) {
+				break;
+		    } 
+		}
+				
+		if (empty($this->arrSetting[CMD_SHELL])) {
+		    $this->raiseError("No shell found");
+		}
+    }
+		
+    /**
+     * Sets any option
+     * 
+     * The options are currently:
+	 * CMD_SHUTDOWN	: Execute commands via a shutdown function 
+	 * CMD_SHELL	: Path to shell
+     * CMD_OUTPUT	: Output stdout from process
+	 * CMD_NOHUP	: Use nohup to detach process
+     * CMD_VERBOSE	: Print errors to stdout
+     *
+     * @param $option is a constant, which corresponds to the
+     * option that should be changed
+     *
+     * @param $setting is the value of the option currently
+     * being toggled.
+     *
+     * @return bool true if succes, else false
+     *
+     * @access public
+     * 
+     * @author Anders Johannsen <anders@johannsen.com>
+     * 
+     **/
+		
+    function setOption ($option, $setting)
+    {
+		if (empty($this->arrConstant[$option])) {
+		    $this->raiseError("No such option: $option");
+		    return false;
+		}
+	
+				
+		switch ($option) {
+		case CMD_OUTPUT:
+		case CMD_SHUTDOWN:
+		case CMD_VERBOSE:
+		case CMD_SEQUENCE:
+		    $this->arrSetting[$option] = $setting;
+		    return true;
+		    break;
+		    
+		case CMD_SHELL:
+		    if (is_executable($setting)) {
+				$this->arrSetting[$option] = $setting;
+				return true;
+		    } else {
+				$this->raiseError("No such shell: $setting");
+				return false;
+		    }
+		    break;
+		    
+					
+		case CMD_NOHUP:
+			if  (empty($setting)) {
+			    $this->arrSetting[$option] = false;
+			    
+			} else if ($location = $this->which("nohup")) {
+			    $this->arrSetting[$option] = true;
+			    
+			} else {
+			    $this->raiseError("Nohup was not found on your system");
+			    return false;
+			}
+			break;
+			
+		}
+    }
+    
+    /**
+     * Add command for execution
+     *
+     * @param $command accepts both arrays and regular strings
+     *
+     * @return bool true if succes, else false
+     *
+     * @access public
+     * 
+     * @author Anders Johannsen <anders@johannsen.com>
+     *
+     **/
+		
+    function command($command) 
+    {
+		if (is_array($command)) {
+		    foreach ($command as $key => $value) {
+				$this->arrCommand[] = $value;
+			}
+			return true;
+
+		} else if (is_string($command)) {
+		    $this->arrCommand[] = $command;
+		    return true;
+		}
+				
+		$this->raiseError("Argument not valid");
+		return false;
+    }
+		
+    /**
+     * Executes the code according to given options
+     *
+     * @return bool true if succes, else false
+     *
+     * @access public
+     * 
+     * @author Anders Johannsen <anders@johannsen.com>
+     *
+     **/
+		
+    function exec() 
+    {
+		// Warning about impossible mix of options
+		if (!empty($this->arrSetting[CMD_OUTPUT])) {
+		    if (!empty($this->arrSetting[CMD_SHUTDOWN]) || !empty($this->arrSetting[CMD_NOHUP])) {
+				$this->raiseError("Error: Commands executed via shutdown functions or nohup cannot return output");
+				return false;
+		    }
+		}
+				
+		// Building command
+		$strCommand = implode(";", $this->arrCommand);
+				
+		$strExec 	= "echo '$strCommand' | ".$this->arrSetting[CMD_SHELL];
+				
+		if (empty($this->arrSetting[CMD_OUTPUT])) {
+		    $strExec = $strExec . ' > /dev/null';
+		}
+				
+		if (!empty($this->arrSetting[CMD_NOHUP])) {
+		    $strExec = 'nohup ' . $strExec;
+		}
+				
+		// Executing 
+		if (!empty($this->arrSetting[CMD_SHUTDOWN])) {
+		    $line = "system(\"$strExec\");";
+		    $function = create_function('', $line);
+		    register_shutdown_function($function);
+		    return true;
+		} else {
+		    return `$strExec`;
+		}
+    }
+
+    /**
+     * Errorhandler. If option CMD_VERBOSE is true,
+     * the error is printed to stdout, otherwise it 
+     * is avaliable in lastError
+     *
+     * @return bool always returns true 
+     *
+     * @access private
+     * 
+     * @author Anders Johannsen <anders@johannsen.com>
+     **/
+		
+    function raiseError($strError) 
+    {
+		if (!empty($this->arrSetting[CMD_VERBOSE])) {
+		    echo $strError;
+		} else {
+		    $this->lastError = $strError;
+		}
+		
+		return true;
+    }
+		
+    /**
+     * Functionality similiar to unix 'which'. Searches the path
+     * for the specified program. 
+     *
+	 * @param $cmd name of the executable to search for 
+	 *
+     * @return string returns the full path if found,
+     * false if not
+     *
+     * @access private
+     * 
+     * @author Anders Johannsen <anders@johannsen.com>
+     **/
+		
+    function which($cmd) 
+    {
+		global $HTTP_ENV_VARS;
+				
+		$arrPath = explode(":", $HTTP_ENV_VARS['PATH']);
+			
+		foreach ($arrPath as $path) {
+		    $location = $path . "/" . $cmd;
+							
+		    if (is_executable($location)) {
+				return $location;
+		    }
+		}
+		return false;
+    }	
+}
+	
+?>