Added MySQL UDF to execute commands on the underlying system:

* sys_eval() to return the standard output
* sys_exec() to return the exit status

It's a patched version of http://mysqludf.org/lib_mysqludf_sys/index.php

extra/mysqludfsys/lib_mysqludf_sys/Makefile

@@ -0,0 +1,4 @@
+LIBDIR=/usr/lib
+
+install:
+	gcc -Wall -I/usr/include/mysql -I. -shared lib_mysqludf_sys.c -o $(LIBDIR)/lib_mysqludf_sys.so

extra/mysqludfsys/lib_mysqludf_sys/install.sh

@@ -0,0 +1,25 @@
+#!/bin/bash
+
+echo "Compiling the MySQL UDF"
+make
+
+if test $? -ne 0; then
+	echo "ERROR: You need libmysqlclient development software installed "
+	echo "to be able to compile this UDF, on Debian/Ubuntu just run:"
+	echo "apt-get install libmysqlclient15-dev"
+	exit 1
+else
+	echo "MySQL UDF compiled successfully"
+fi
+
+echo -e "\nPlease provide your MySQL root password and press RETURN: \c"
+read PASSWORD
+
+mysql -u root --password=$PASSWORD mysql < lib_mysqludf_sys.sql
+
+if test $? -ne 0; then
+	echo "ERROR: unable to install the UDF"
+	exit 1
+else
+	echo "MySQL UDF installed successfully"
+fi

extra/mysqludfsys/lib_mysqludf_sys/lib_mysqludf_sys.c

@@ -0,0 +1,426 @@
+/* 
+	lib_mysqludf_sys - a library with miscellaneous (operating) system level functions
+	Copyright (C) 2007  Roland Bouman 
+	Copyright (C) 2008-2009  Roland Bouman and Bernardo Damele A. G.
+	web: http://www.mysqludf.org/
+	email: mysqludfs@gmail.com, bernardo.damele@gmail.com
+	
+	This library is free software; you can redistribute it and/or
+	modify it under the terms of the GNU Lesser General Public
+	License as published by the Free Software Foundation; either
+	version 2.1 of the License, or (at your option) any later version.
+	
+	This library is distributed in the hope that it will be useful,
+	but WITHOUT ANY WARRANTY; without even the implied warranty of
+	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+	Lesser General Public License for more details.
+	
+	You should have received a copy of the GNU Lesser General Public
+	License along with this library; if not, write to the Free Software
+	Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+*/
+#if defined(_WIN32) || defined(_WIN64) || defined(__WIN32__) || defined(WIN32)
+#define DLLEXP __declspec(dllexport) 
+#else
+#define DLLEXP
+#endif
+
+#ifdef STANDARD
+#include <string.h>
+#include <stdlib.h>
+#include <time.h>
+#ifdef __WIN__
+typedef unsigned __int64 ulonglong;
+typedef __int64 longlong;
+#else
+typedef unsigned long long ulonglong;
+typedef long long longlong;
+#endif /*__WIN__*/
+#else
+#include <my_global.h>
+#include <my_sys.h>
+#endif
+#include <mysql.h>
+#include <m_ctype.h>
+#include <m_string.h>
+#include <stdlib.h>
+
+#include <ctype.h>
+
+#ifdef HAVE_DLOPEN
+#ifdef	__cplusplus
+extern "C" {
+#endif
+
+#define LIBVERSION "lib_mysqludf_sys version 0.0.3"
+
+#ifdef __WIN__
+#define SETENV(name,value)		SetEnvironmentVariable(name,value);
+#else
+#define SETENV(name,value)		setenv(name,value,1);		
+#endif
+
+DLLEXP 
+my_bool lib_mysqludf_sys_info_init(
+	UDF_INIT *initid
+,	UDF_ARGS *args
+,	char *message
+);
+
+DLLEXP 
+void lib_mysqludf_sys_info_deinit(
+	UDF_INIT *initid
+);
+
+DLLEXP 
+char* lib_mysqludf_sys_info(
+	UDF_INIT *initid
+,	UDF_ARGS *args
+,	char* result
+,	unsigned long* length
+,	char *is_null
+,	char *error
+);
+
+/**
+ * sys_get
+ * 
+ * Gets the value of the specified environment variable.
+ */
+DLLEXP 
+my_bool sys_get_init(
+	UDF_INIT *initid
+,	UDF_ARGS *args
+,	char *message
+);
+
+DLLEXP 
+void sys_get_deinit(
+	UDF_INIT *initid
+);
+
+DLLEXP 
+char* sys_get(
+	UDF_INIT *initid
+,	UDF_ARGS *args
+,	char* result
+,	unsigned long* length
+,	char *is_null
+,	char *error
+);
+
+/**
+ * sys_set
+ * 
+ * Sets the value of the environment variables.
+ * This function accepts a set of name/value pairs
+ * which are then set as environment variables.
+ * Use sys_get to retrieve the value of such a variable 
+ */
+DLLEXP 
+my_bool sys_set_init(
+	UDF_INIT *initid
+,	UDF_ARGS *args
+,	char *message
+);
+
+DLLEXP 
+void sys_set_deinit(
+	UDF_INIT *initid
+);
+
+DLLEXP 
+long long sys_set(
+	UDF_INIT *initid
+,	UDF_ARGS *args
+,	char *is_null
+,	char *error
+);
+
+/**
+ * sys_exec
+ * 
+ * executes the argument commandstring and returns its exit status.
+ * Beware that this can be a security hazard.
+ */
+DLLEXP 
+my_bool sys_exec_init(
+	UDF_INIT *initid
+,	UDF_ARGS *args
+,	char *message
+);
+
+DLLEXP 
+void sys_exec_deinit(
+	UDF_INIT *initid
+);
+
+DLLEXP 
+my_ulonglong sys_exec(
+	UDF_INIT *initid
+,	UDF_ARGS *args
+,	char *is_null
+,	char *error
+);
+
+/**
+ * sys_eval
+ * 
+ * executes the argument commandstring and returns its standard output.
+ * Beware that this can be a security hazard.
+ */
+DLLEXP 
+my_bool sys_eval_init(
+	UDF_INIT *initid
+,	UDF_ARGS *args
+,	char *message
+);
+
+DLLEXP 
+void sys_eval_deinit(
+	UDF_INIT *initid
+);
+
+DLLEXP 
+char* sys_eval(
+	UDF_INIT *initid
+,	UDF_ARGS *args
+,	char* result
+,	unsigned long* length
+,	char *is_null
+,	char *error
+);
+
+
+#ifdef	__cplusplus
+}
+#endif
+
+/**
+ * lib_mysqludf_sys_info
+ */
+my_bool lib_mysqludf_sys_info_init(
+	UDF_INIT *initid
+,	UDF_ARGS *args
+,	char *message
+){
+	my_bool status;
+	if(args->arg_count!=0){
+		strcpy(
+			message
+		,	"No arguments allowed (udf: lib_mysqludf_sys_info)"
+		);
+		status = 1;
+	} else {
+		status = 0;
+	}
+	return status;
+}
+void lib_mysqludf_sys_info_deinit(
+	UDF_INIT *initid
+){
+}
+char* lib_mysqludf_sys_info(
+	UDF_INIT *initid
+,	UDF_ARGS *args
+,	char* result
+,	unsigned long* length
+,	char *is_null
+,	char *error
+){
+	strcpy(result,LIBVERSION);
+	*length = strlen(LIBVERSION);
+	return result;
+}
+
+my_bool sys_get_init(
+	UDF_INIT *initid
+,	UDF_ARGS *args
+,	char *message
+){
+	if(args->arg_count==1
+	&&	args->arg_type[0]==STRING_RESULT){
+		initid->maybe_null = 1;
+		return 0;
+	} else {
+		strcpy(
+			message
+		,	"Expected exactly one string type parameter"
+		);		
+		return 1;
+	}
+}
+void sys_get_deinit(
+	UDF_INIT *initid
+){
+}
+char* sys_get(
+	UDF_INIT *initid
+,	UDF_ARGS *args
+,	char* result
+,	unsigned long* length
+,	char *is_null
+,	char *error
+){
+	char* value = getenv(args->args[0]);
+	if(value == NULL){
+		*is_null = 1;
+	} else {
+		*length = strlen(value);
+	} 
+	return value;
+}
+
+my_bool sys_set_init(
+	UDF_INIT *initid
+,	UDF_ARGS *args
+,	char *message
+){
+	if(args->arg_count!=2){
+		strcpy(
+			message
+		,	"Expected exactly two arguments"
+		);		
+		return 1;
+	}
+	if(args->arg_type[0]!=STRING_RESULT){
+		strcpy(
+			message
+		,	"Expected string type for name parameter"
+		);		
+		return 1;
+	}
+	args->arg_type[1]=STRING_RESULT;
+	if((initid->ptr=malloc(
+		args->lengths[0]
+	+	1
+	+	args->lengths[1]
+	+	1
+	))==NULL){
+		strcpy(
+			message
+		,	"Could not allocate memory"
+		);		
+		return 1;
+	}	
+	return 0;
+}
+void sys_set_deinit(
+	UDF_INIT *initid
+){
+	if (initid->ptr!=NULL){
+		free(initid->ptr);
+	}
+}
+long long sys_set(
+	UDF_INIT *initid
+,	UDF_ARGS *args
+,	char *is_null
+,	char *error
+){	
+	char *name = initid->ptr;
+	char *value = name + args->lengths[0] + 1; 
+	memcpy(
+		name
+	,	args->args[0]
+	,	args->lengths[0]
+	);
+	*(name + args->lengths[0]) = '\0';
+	memcpy(
+		value
+	,	args->args[1]
+	,	args->lengths[1]
+	);
+	*(value + args->lengths[1]) = '\0';
+	return SETENV(name,value);		
+}
+
+my_bool sys_exec_init(
+	UDF_INIT *initid
+,	UDF_ARGS *args
+,	char *message
+){
+	unsigned int i=0;
+	if(args->arg_count == 1
+	&& args->arg_type[i]==STRING_RESULT){
+		return 0;
+	} else {
+		strcpy(
+			message
+		,	"Expected exactly one string type parameter"
+		);		
+		return 1;
+	}
+}
+void sys_exec_deinit(
+	UDF_INIT *initid
+){
+}
+my_ulonglong sys_exec(
+	UDF_INIT *initid
+,	UDF_ARGS *args
+,	char *is_null
+,	char *error
+){
+	return system(args->args[0]);
+}
+
+my_bool sys_eval_init(
+	UDF_INIT *initid
+,	UDF_ARGS *args
+,	char *message
+){
+	unsigned int i=0;
+	if(args->arg_count == 1
+	&& args->arg_type[i]==STRING_RESULT){
+		return 0;
+	} else {
+		strcpy(
+			message
+		,	"Expected exactly one string type parameter"
+		);		
+		return 1;
+	}
+}
+void sys_eval_deinit(
+	UDF_INIT *initid
+){
+}
+char* sys_eval(
+	UDF_INIT *initid
+,	UDF_ARGS *args
+,	char* result
+,	unsigned long* length
+,	char *is_null
+,	char *error
+){
+	FILE *pipe;
+	char line[1024];
+	unsigned long outlen, linelen;
+
+	result = malloc(1);
+	outlen = 0;
+
+	pipe = popen(args->args[0], "r");
+
+	while (fgets(line, sizeof(line), pipe) != NULL) {
+		linelen = strlen(line);
+		result = realloc(result, outlen + linelen);
+		strncpy(result + outlen, line, linelen);
+		outlen = outlen + linelen;
+	}
+
+	pclose(pipe);
+
+	if (!(*result) || result == NULL) {
+		*is_null = 1;
+	} else {
+    	result[outlen] = 0x00;
+	    *length = strlen(result);
+	}
+
+    return result;
+}
+
+
+#endif /* HAVE_DLOPEN */

extra/mysqludfsys/lib_mysqludf_sys/lib_mysqludf_sys.html

@@ -0,0 +1,208 @@
+<?xml version="1.0" encoding="UTF-8" ?>
+<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
+<html xmlns="http://www.w3.org/1999/xhtml">
+<head>
+<link rel="stylesheet" type="text/css" href="../mysqludf.css"/>
+<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
+<title>lib_mysqludf_sys - A library of MySQL UDFs for working with the environment in which MySQL runs</title>
+</head>
+<body>
+	<div>
+		<a href="../index.html">Top</a>
+	|	<a href="../mysql_udf_repository_libraries.html">Up</a>
+	</div>
+	<h1>lib_mysqludf_sys</h1>
+	<div>
+		<a href="lib_mysqludf_sys.html">Documentation</a>
+	|	<a href="lib_mysqludf_sys.so">Binary</a>
+	|	<a href="lib_mysqludf_sys.sql">Installation</a>
+	|	<a href="lib_mysqludf_sys.c">Source</a>
+	|	<a href="lib_mysqludf_sys_0.0.2.tar.gz">tar.gz</a>
+	</div>
+	<p>
+		This library <code>lib_mysqludf_sys</code> contains a number of functions that allows one to interact with the operating system.		
+	</p>
+	<ol>
+		<li><a href="#sys_exec"><code>sys_exec</code></a> - executes an arbitrary command, and can thus be used to launch an external application.</li>
+		<li><a href="#sys_get"><code>sys_get</code></a> - gets the value of an environment variable.</li>
+		<li><a href="#sys_set"><code>sys_set</code></a> - create an environment variable, or update the value of an existing environment variable.</li>
+	</ol>
+	<p>
+		Use <a href="#lib_mysqludf_sys_info"><code>lib_mysqludf_sys_info()</code></a> to obtain information about the currently installed version of <code>lib_mysqludf_sys</code>.
+	</p>
+	
+	<a name="sys_exec"></a><h2>sys_exec</h2>
+	<p>
+		<code>sys_exec</code> takes one command string argument and executes it.
+	</p>
+	<h3>Syntax</h3>
+<pre>sys_exec(<b>arg1</b>)</pre>
+	<h3>Parameters and Return Values</h3>
+	<dl>
+		<dt><code><b>arg1</b></code></dt>
+		<dd>
+			A command string valid for the current operating system or execution environment.
+		</dd>
+		<dt>returns</dt>
+		<dd>
+			An (integer) exit code returned by the executed process.
+		</dd>
+	</dl>
+	<h3>Installation</h3>
+	<p>
+		Place the shared library binary in an appropriate location. 
+		Log in to mysql as root or as another user with sufficient privileges, and select any database.		
+		Then, create the function using the following DDL statement:
+	</p>
+	<pre>
+CREATE FUNCTION sys_exec RETURNS INT SONAME 'lib_mysqludf_sys.so';	
+	</pre>
+	<p>
+		The function will be globally available in all databases.
+	</p>
+	<p>
+		The deinstall the function, run the following statement:
+	</p>
+	<pre>
+DROP FUNCTION sys_exec;
+	</pre>
+	<h3>Examples</h3>
+	<p>
+		None yet
+	</p>
+	<h3>A Note of Caution</h3>
+	<p>
+		Be very careful in deciding whether you need this function. 
+		UDFs are available to all database users - you cannot grant EXECUTE privileges for them.
+		As the commandstring passed to <code>sys_exec</code> can do pretty much everything, 
+		exposing the function poses a very real security hazard.
+	</p>
+	<p>
+		Even for a benign user, it is possible to accidentally do a lot of damage with it.
+		The call will be executed with the privileges of the os user that runs MySQL, 
+		so it is entirely feasible to delete MySQL's data directory, or worse.		
+	</p>
+	<p>	
+		The function is intended for specialized MySQL applications where one needs extended 
+		control over the operating system. 
+		Currently, we do not have UDF's for ftp, email and http, 
+		and this function can be used to implement such functionality in case it is really necessary
+		(datawarehouse staging areas could be a case in example).
+	</p>
+	<p>
+		You have been warned! If you don't see the hazard, please don't try to find it; just trust me on this.
+	</p>
+	<a name="sys_get"></a><h2>sys_get</h2>
+	<p>
+		<code>sys_get</code> takes the name of an environment variable and returns the value of the variable.
+	</p>
+	<h3>Syntax</h3>
+<pre>sys_get([<b>arg1</b>)</pre>
+	<h3>Parameters and Return Values</h3>
+	<dl>
+		<dt><code><b>arg1</b></code></dt>
+		<dd>
+			A string that denotes the name of an environment value.			
+		</dd>
+		<dt>returns</dt>
+		<dd>
+			If the variable exists, a string containing the value of the environment variable.
+			If the variable does not exist, the function return NULL.
+		</dd>
+	</dl>
+	<h3>Installation</h3>
+	<p>
+		Place the shared library binary in an appropriate location. 
+		Log in to mysql as root or as another user with sufficient privileges, and select any database.		
+		Then, create the function using the following DDL statement:
+	</p>
+	<pre>
+CREATE FUNCTION sys_get RETURNS STRING SONAME 'lib_mysqludf_sys.so';	
+	</pre>
+	<p>
+		The function will be globally available in all databases.
+	</p>
+	<p>
+		The deinstall the function, run the following statement:
+	</p>
+	<pre>
+DROP FUNCTION sys_get;
+	</pre>
+	<h3>Examples</h3>
+	<p>
+		None yet
+	</p>
+	<h3>A Note of Caution</h3>
+	<p>
+		Be very careful in deciding whether you need this function. 
+		UDFs are available to all database users - you cannot grant EXECUTE privileges for them.
+		The variables known in the environment where mysql runs are freely accessible using this function.
+		Any user can get access to potentially secret information, such as
+		the user that is running mysqld, the path of the user's home directory etc.
+	</p>
+	<p>	
+		The function is intended for specialized MySQL applications where one needs extended 
+		control over the operating system. 
+	</p>
+	<p>
+		You have been warned! If you don't see the hazard, please don't try to find it; just trust me on this.
+	</p>
+	<a name="sys_set"></a><h2>sys_set</h2>
+	<p>
+		<code>sys_get</code> takes the name of an environment variable and returns the value of the variable.
+	</p>
+	<h3>Syntax</h3>
+<pre>sys_set([<b>arg1, arg2</b>)</pre>
+	<h3>Parameters and Return Values</h3>
+	<dl>
+		<dt><code><b>arg1</b></code></dt>
+		<dd>
+			A string that denotes the name of an environment value.			
+		</dd>
+		<dt><code><b>arg2</b></code></dt>
+		<dd>
+			An expression that contains the value that is to be assigned to the environment variable.			
+		</dd>
+		<dt>returns</dt>
+		<dd>
+			0 if the assignment or creation succeed.
+			non-zero otherwise.
+		</dd>
+	</dl>
+	<h3>Installation</h3>
+	<p>
+		Place the shared library binary in an appropriate location. 
+		Log in to mysql as root or as another user with sufficient privileges, and select any database.		
+		Then, create the function using the following DDL statement:
+	</p>
+	<pre>
+CREATE FUNCTION sys_set RETURNS STRING SONAME 'lib_mysqludf_sys.so';	
+	</pre>
+	<p>
+		The function will be globally available in all databases.
+	</p>
+	<p>
+		The deinstall the function, run the following statement:
+	</p>
+	<pre>
+DROP FUNCTION sys_set;
+	</pre>
+	<h3>Examples</h3>
+	<p>
+		None yet
+	</p>
+	<h3>A Note of Caution</h3>
+	<p>
+		Be very careful in deciding whether you need this function. 
+		UDFs are available to all database users - you cannot grant EXECUTE privileges for them.
+		This function will overwrite existing environment variables.
+	</p>
+	<p>	
+		The function is intended for specialized MySQL applications where one needs extended 
+		control over the operating system. 
+	</p>
+	<p>
+		You have been warned! If you don't see the hazard, please don't try to find it; just trust me on this.
+	</p>
+</body>
+</html

extra/mysqludfsys/lib_mysqludf_sys/lib_mysqludf_sys.sql

@@ -0,0 +1,33 @@
+/* 
+	lib_mysqludf_sys - a library with miscellaneous (operating) system level functions
+	Copyright (C) 2007  Roland Bouman 
+	Copyright (C) 2008-2009  Roland Bouman and Bernardo Damele A. G.
+	web: http://www.mysqludf.org/
+	email: mysqludfs@gmail.com, bernardo.damele@gmail.com
+	
+	This library is free software; you can redistribute it and/or
+	modify it under the terms of the GNU Lesser General Public
+	License as published by the Free Software Foundation; either
+	version 2.1 of the License, or (at your option) any later version.
+	
+	This library is distributed in the hope that it will be useful,
+	but WITHOUT ANY WARRANTY; without even the implied warranty of
+	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+	Lesser General Public License for more details.
+	
+	You should have received a copy of the GNU Lesser General Public
+	License along with this library; if not, write to the Free Software
+	Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+*/
+
+DROP FUNCTION IF EXISTS lib_mysqludf_sys_info;
+DROP FUNCTION IF EXISTS sys_get;
+DROP FUNCTION IF EXISTS sys_set;
+DROP FUNCTION IF EXISTS sys_exec;
+DROP FUNCTION IF EXISTS sys_eval;
+
+CREATE FUNCTION lib_mysqludf_sys_info RETURNS string SONAME 'lib_mysqludf_sys.so';
+CREATE FUNCTION sys_get RETURNS string SONAME 'lib_mysqludf_sys.so';
+CREATE FUNCTION sys_set RETURNS int SONAME 'lib_mysqludf_sys.so';
+CREATE FUNCTION sys_exec RETURNS int SONAME 'lib_mysqludf_sys.so';
+CREATE FUNCTION sys_eval RETURNS string SONAME 'lib_mysqludf_sys.so';

extra/mysqludfsys/lib_mysqludf_sys_0.0.3.patch

@@ -0,0 +1,213 @@
+diff -uN lib_mysqludf_sys/install.sh lib_mysqludf_sys_0.0.3/install.sh
+--- lib_mysqludf_sys/install.sh	1970-01-01 01:00:00.000000000 +0100
++++ lib_mysqludf_sys_0.0.3/install.sh	2009-01-15 16:04:50.000000000 +0000
+@@ -0,0 +1,25 @@
++#!/bin/bash
++
++echo "Compiling the MySQL UDF"
++make
++
++if test $? -ne 0; then
++	echo "ERROR: You need libmysqlclient development software installed "
++	echo "to be able to compile this UDF, on Debian/Ubuntu just run:"
++	echo "apt-get install libmysqlclient15-dev"
++	exit 1
++else
++	echo "MySQL UDF compiled successfully"
++fi
++
++echo -e "\nPlease provide your MySQL root password and press RETURN: \c"
++read PASSWORD
++
++mysql -u root --password=$PASSWORD mysql < lib_mysqludf_sys.sql
++
++if test $? -ne 0; then
++	echo "ERROR: unable to install the UDF"
++	exit 1
++else
++	echo "MySQL UDF installed successfully"
++fi
+Binary files lib_mysqludf_sys/lib_mysqludf_sys_0.0.2.tar.gz and lib_mysqludf_sys_0.0.3/lib_mysqludf_sys_0.0.2.tar.gz differ
+diff -uN lib_mysqludf_sys/lib_mysqludf_sys.c lib_mysqludf_sys_0.0.3/lib_mysqludf_sys.c
+--- lib_mysqludf_sys/lib_mysqludf_sys.c	2007-08-05 13:46:43.000000000 +0100
++++ lib_mysqludf_sys_0.0.3/lib_mysqludf_sys.c	2009-01-15 15:55:33.000000000 +0000
+@@ -1,8 +1,9 @@
+ /* 
+ 	lib_mysqludf_sys - a library with miscellaneous (operating) system level functions
+ 	Copyright (C) 2007  Roland Bouman 
+-	web: http://www.xcdsql.org/MySQL/UDF/ 
+-	email: mysqludfs@gmail.com
++	Copyright (C) 2008-2009  Roland Bouman and Bernardo Damele A. G.
++	web: http://www.mysqludf.org/
++	email: mysqludfs@gmail.com, bernardo.damele@gmail.com
+ 	
+ 	This library is free software; you can redistribute it and/or
+ 	modify it under the terms of the GNU Lesser General Public
+@@ -51,7 +52,7 @@
+ extern "C" {
+ #endif
+ 
+-#define LIBVERSION "lib_mysqludf_sys version 0.0.2"
++#define LIBVERSION "lib_mysqludf_sys version 0.0.3"
+ 
+ #ifdef __WIN__
+ #define SETENV(name,value)		SetEnvironmentVariable(name,value);
+@@ -139,7 +140,7 @@
+ /**
+  * sys_exec
+  * 
+- * executes the argument commandstring.
++ * executes the argument commandstring and returns its exit status.
+  * Beware that this can be a security hazard.
+  */
+ DLLEXP 
+@@ -162,6 +163,34 @@
+ ,	char *error
+ );
+ 
++/**
++ * sys_eval
++ * 
++ * executes the argument commandstring and returns its standard output.
++ * Beware that this can be a security hazard.
++ */
++DLLEXP 
++my_bool sys_eval_init(
++	UDF_INIT *initid
++,	UDF_ARGS *args
++,	char *message
++);
++
++DLLEXP 
++void sys_eval_deinit(
++	UDF_INIT *initid
++);
++
++DLLEXP 
++char* sys_eval(
++	UDF_INIT *initid
++,	UDF_ARGS *args
++,	char* result
++,	unsigned long* length
++,	char *is_null
++,	char *error
++);
++
+ 
+ #ifdef	__cplusplus
+ }
+@@ -336,5 +365,62 @@
+ 	return system(args->args[0]);
+ }
+ 
++my_bool sys_eval_init(
++	UDF_INIT *initid
++,	UDF_ARGS *args
++,	char *message
++){
++	unsigned int i=0;
++	if(args->arg_count == 1
++	&& args->arg_type[i]==STRING_RESULT){
++		return 0;
++	} else {
++		strcpy(
++			message
++		,	"Expected exactly one string type parameter"
++		);		
++		return 1;
++	}
++}
++void sys_eval_deinit(
++	UDF_INIT *initid
++){
++}
++char* sys_eval(
++	UDF_INIT *initid
++,	UDF_ARGS *args
++,	char* result
++,	unsigned long* length
++,	char *is_null
++,	char *error
++){
++	FILE *pipe;
++	char line[1024];
++	unsigned long outlen, linelen;
++
++	result = malloc(1);
++	outlen = 0;
++
++	pipe = popen(args->args[0], "r");
++
++	while (fgets(line, sizeof(line), pipe) != NULL) {
++		linelen = strlen(line);
++		result = realloc(result, outlen + linelen);
++		strncpy(result + outlen, line, linelen);
++		outlen = outlen + linelen;
++	}
++
++	pclose(pipe);
++
++	if (!(*result) || result == NULL) {
++		*is_null = 1;
++	} else {
++    	result[outlen] = 0x00;
++	    *length = strlen(result);
++	}
++
++    return result;
++}
++
+ 
+ #endif /* HAVE_DLOPEN */
+Binary files lib_mysqludf_sys/lib_mysqludf_sys.so and lib_mysqludf_sys_0.0.3/lib_mysqludf_sys.so differ
+diff -uN lib_mysqludf_sys/lib_mysqludf_sys.sql lib_mysqludf_sys_0.0.3/lib_mysqludf_sys.sql
+--- lib_mysqludf_sys/lib_mysqludf_sys.sql	2007-06-02 20:42:53.000000000 +0100
++++ lib_mysqludf_sys_0.0.3/lib_mysqludf_sys.sql	2009-01-15 15:57:34.000000000 +0000
+@@ -1,8 +1,9 @@
+ /* 
+ 	lib_mysqludf_sys - a library with miscellaneous (operating) system level functions
+ 	Copyright (C) 2007  Roland Bouman 
+-	web: http://www.xcdsql.org/MySQL/UDF/ 
+-	email: mysqludfs@gmail.com
++	Copyright (C) 2008-2009  Roland Bouman and Bernardo Damele A. G.
++	web: http://www.mysqludf.org/
++	email: mysqludfs@gmail.com, bernardo.damele@gmail.com
+ 	
+ 	This library is free software; you can redistribute it and/or
+ 	modify it under the terms of the GNU Lesser General Public
+@@ -19,12 +20,14 @@
+ 	Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+ 
+-drop function lib_mysqludf_sys_info;
+-drop function sys_get;
+-drop function sys_set;
+-drop function sys_exec;
++DROP FUNCTION IF EXISTS lib_mysqludf_sys_info;
++DROP FUNCTION IF EXISTS sys_get;
++DROP FUNCTION IF EXISTS sys_set;
++DROP FUNCTION IF EXISTS sys_exec;
++DROP FUNCTION IF EXISTS sys_eval;
+ 
+-create function lib_mysqludf_sys_info returns string soname 'lib_mysqludf_sys.so';
+-create function sys_get returns string soname 'lib_mysqludf_sys.so';
+-create function sys_set returns int soname 'lib_mysqludf_sys.so';
+-create function sys_exec returns int soname 'lib_mysqludf_sys.so';
++CREATE FUNCTION lib_mysqludf_sys_info RETURNS string SONAME 'lib_mysqludf_sys.so';
++CREATE FUNCTION sys_get RETURNS string SONAME 'lib_mysqludf_sys.so';
++CREATE FUNCTION sys_set RETURNS int SONAME 'lib_mysqludf_sys.so';
++CREATE FUNCTION sys_exec RETURNS int SONAME 'lib_mysqludf_sys.so';
++CREATE FUNCTION sys_eval RETURNS string SONAME 'lib_mysqludf_sys.so';
+diff -uN lib_mysqludf_sys/Makefile lib_mysqludf_sys_0.0.3/Makefile
+--- lib_mysqludf_sys/Makefile	2007-08-05 12:54:53.000000000 +0100
++++ lib_mysqludf_sys_0.0.3/Makefile	2009-01-15 15:52:48.000000000 +0000
+@@ -1,6 +1,4 @@
+-linux: \
+- lib_mysqludf_sys.so
++LIBDIR=/usr/lib
+ 
+-lib_mysqludf_sys.so: \
+- 
+-	gcc -Wall -I/opt/mysql/mysql/include -I. -shared lib_mysqludf_sys.c -o lib_mysqludf_sys.so
++install:
++	gcc -Wall -I/usr/include/mysql -I. -shared lib_mysqludf_sys.c -o $(LIBDIR)/lib_mysqludf_sys.so