To run the Alpha version of Aviate, extract the downloaded file and use setup.py. Later examples in this chapter show off usage.

prompt> tar -xzvf aviate-1.0.tar.gz
prompt> cd aviate-1.0
prompt> sudo python setup.py install

This installs the application in your distribution's Python packages directory, and creates a launch script aviate in /usr/bin.

The following are the Python modules Aviate requires: paramiko, 1.7.3 or higher; pysvn, 1.6.0; pexpect, 2.3 or higher; pycrypto, 2.0.1 or higher.

You may install the binary of the dependencies on Debian/Linux by:

prompt> apt-get install python-crypto python-svn python-mysqldb mysql-client-5.0 rsync

You may install the binary of the dependencies on Fedora/Redhat Linux by:

prompt> yum install python-crypto pysvn MySQL-python mysql rsync

Note: Aviate has only been tested on Python 2.5.

Aviate on Windows does not require any installation. Simply extract the ZIP file and move the directory to the location you want.

Defaults are a mean to assign a global default value for parameters that are used commonly, one of these is the retry default. For most commands, you can specify the number of times the execution of the command is retried till it succeeds, the default of which if not specifically specified is only 1 time. The following are two commands in which one specifies a retry count while the other not.

<fs:mkdir destination="local" path="aviate-tests/1" retry="2" />
<fs:mkdir destination="local" path="aviate-tests/2" />

In the above example, the first command will retry execution twice, while the second will retry execution once since this is the local default of all commands. To make the second command retry execution 4 times, then at the top level of the DepFile, you should override the default value as follows:

<default name="retry" count="4" />

The following are the available defaults you can override:

Variables are named values that can change from one execution to another based on different user input. There are two types of variables: Arguments, whose values are retrieved from the command line, and Properties, whose values are retrieved from a Property File.

For both types, allowed characeters in variable names are letters, numbers, dots, underscores and dashes. Variables are evaluated by prefixing the variable name with ${ and postfixing it with }. Thus, to evaluate a variable named myvar:

<fs:copy source="local" destination="ftp_server" from="${myvar}" to="/var/www" />

<variables>
	<argument name="arg1" required="true" />
	<argument name="arg2" default="val2" />
	<argument name="arg3" question="What is the value of 'arg3'?" />
</variables>

prompt> aviate.exe example.dep arg1=val1 arg2=someval2

[ftp]
username = me
password = mine

[mysql]
host = 127.0.0.1

<variables>
	<properties file="prop1.cfg" />
	<properties file="prop2.cfg" />
</variables>

Constants are a way to define named values inside the DepFile, and to refer to them in other parts of the DepFile. Contrary to Arguments and Variables, the value of a constant is specifically specified in the DepFile, and there are a number of pre-defined constants. An example of defining a constant follows.

<constant name="CONFIG_FILE_NAME" value="main.cfg" />

Allowed characeters in constant names are letters, numbers, dots, underscores and dashes. Constants are evaluated by prefixing the constant name with #{ and postfixing it with }. To evaluate the constant defined above:

<fs:copy source="local" destination="ftp_server" from="#{CONFIG_FILE_NAME}" to="/var/www" />

For a list of the pre-defined constants, see the Pre-Defined Constants appendix.

FileSystem servers, like a Local Server, an FTP Server or an SSH Server, have a parameter called "root". With this parameter you can specify the root directory to assume for all relative paths specified for that directory. For example, if you were to define the root of an FTP server as /public_html, then to copy the file config.php into the directory /public_html/config, you can either copy that file to the absolute path /public_html/config or the relative path config. If you do not specify the root for every server, then for POSIX Servers the root is assumed to be /, and for Windows Servers it is assumed to be C:\.

A target is the main action you want to perform, like installing a new application or updating an existing one. When you execute a DepFile, you must specify the name of the target to execute. A target can depend on other targets, in which case before execution begins, Aviate takes care of resolving the dependency between Targets to decide on the order of their execution. A DepFile must define at least one Target.

Each Target has a unique name that identifies. In a Target's name, allowed characeters are letters, numbers, dots, underscores and dashes.

The next example illustrates three Targets, one of which depends on another.

<targets>
	<target name="target_1" >
		<!-- ... -->
	</target>
	<target name="target_2" depends="target_1" >
		<!-- ... -->
	</target>
	<target name="target_3" >
		<!-- ... -->
	</target>
</targets>

If you are using dependency between Targets, be sure there are no cycles in your dependency graphs. If there are, Aviate will refuse to execute the Target.

A Task is a grouping of Commands that share a common goal, or describe a single phase of execution. Executing a Target leads to the execution of all of its tasks; in sequential order with regards to Task dependency. Aviate takes care of resolving the dependency between Tasks to decide on the order of their execution. A target must contain at least one Task.

Each Task has a unique name that identifies. In a Task's name, allowed characeters are letters, numbers, dots, underscores and dashes.

The next example illustrates three Tasks, one of which depends on another.

<targets>
	<target name="target_1" >
		<task name="task_1" >
			<!-- ... -->
		</task>
		<task name="task_2" depends="task_1" >
			<!-- ... -->
		</task>
		<task name="task_3" >
			<!-- ... -->
		</task>
	</target>
</targets>

If you are using dependency between Tasks, be sure there are no cycles in your dependency graphs. If there are, Aviate will refuse to execute the Task.

A Command is the unit of execution. A Command is what copies a file, creates a database, exports a copy from a Subversion repository, or syncs a local directory to a remote one over SSH.

All of Aviate's commands are server-aware, and all run on zero or more servers. A command that executes on zero servers is said to be a Virtual Command, an example of which is the echo command which merely prints on the screen. A command that executes on one server is said to have a destination of that server; an example of which is fs:delete, a command which allows you to delete a file or directory from a filesystem on a destination server. A command that executes on two servers is said to have a source and a destination; an example of which is fs:copy, with which you can copy a file or directory from a source to a destination server's filesystem.

Except Virtual Commands, all Commands are referenced by using a namespace-qualified name. For example, the Copy Command belongs to the FileSystem namespace, and is associated with the tag fs:copy. Similarily, db:create to create a database, web:download to download a file from the web, vc:checkout to checkout from a version control system, and so on.

>A FileSet is a definition of a number of rules that declare match patterns against files or directories. These patterns can be used by some Commands to filter their operation. For example, a Copy Command may exclude a number of files or directories who are matched by the definition in a FileSet. An example declaration of a FileSet in a DepFile is:

<fileset name="set1">
	<match parent="/var/www/uploads" />
	<match parent="/var/www/" name="(.*)\.pyc" />
	<match parent="/var/www/" name="log" type="directory" />
</fileset>

A match entry is a condition that is applied to each file or directory. Each entry can consist of up to three conditions; parent, name or type. If more than one condition is specified, they are ANDed together. The "parent" condition is a regular expression that is applied against the parent directory of the current item, whether it is a file or directory. The "name" condition is a regular expression that is applied against the name of the current item, whether it is a file or directory. The "type" condition restricts applying the match to either a "file or "directory".

A List is a named collection of ordered values. It can be used with commands that can take list of data, like the db:sql Command. A List must be locally defined within a Command, and must have a unique name within the scope of its enacpsulating Command.

<db:sql destination="sql_server" statements="mystat_1" database="test_db" >
	<list name="mystat_1">
		<entry value="create table test (id INT, data VARCHAR(100));" />
		<entry value="insert into test values ('1', 'one');" />
		<entry value="insert into test values ('2', 'two');" />
	</list>
</db:sql>

A Dictionary is a named collection of ordered pairs of keys and values. It can be used with commands that can take dictionaries of data, like the fs:rsync Command. A Dictionary must be locally defined within a Command, and must have a unique name within the scope of its enacpsulating Command.

Each entry of the Dictionary must have a name (the key), but does not need to have a value. If a value is not specified, an empty string will be assumed.

<fs:rsync source="local" destination="ftp_server" from="/var/www" to="/var/www" options="opt">
	<dictionary name="opt">
		<entry name="--max-size" value="10000" />
		<entry name="-r" />
	</dictionary>
</fs:rsync>

Description. Each DepFile has as its root a project tag. Only one such tag must exist in a DepFile,and it must have defined for it a project name, and optionally a schema version. An example DepFile looks like:

<?xml version="1.0" encoding="iso-8859-1"?>
<project>
	...
</project>

Description. Defaults are a mean to assign a global default value for parameters that are used commonly, one of these is the retry default. For most commands, you can specify the number of times the execution of the command is retried till it succeeds, the default of which if not specifically specified is only 1 time. The following are two commands in which one specifies a retry count while the other not.

<fs:mkdir destination="local" path="aviate-tests/1" retry="2" />
<fs:mkdir destination="local" path="aviate-tests/2" />

In the above example, the first command will retry execution twice, while the second will retry execution once since this is the local default of all commands. To make the second command retry execution 4 times, then at the top level of the DepFile, you should override the default value as follows:

<defaults>
	<default name="retry" count="4" />
</defaults>

Description. The following are the available defaults you can override:

An example follows:

<defaults>
	<default name="retry" count="4" />
	<default name="halt" count="false" />
</defaults>

Description. Variables are all name/value pairs that can be referenced in a DepFile; Aviate automatically subistitutes occurences of ${name} in a DepFile by the variable's ${value}. A variable can be either a command line argument, whose name is defined with an argument tag and whose value is retrieved from the command line interface, or it can be retrieved from a property file (an INI-like file).

<variables>
	<argument name="username" required="true" default="root" question="What's the server's username?" />
	<argument name="password" question="What's the server's password?" />
	<property file="properties.ini" />
</variables>

Arguments have higher precedence than Properties, and variable precedence is bound by the order of its definition. For example, if a property file defined a variable X.Y to 1, and then a property file defined X.Y as 2, then it will be stored as 2. Whatever the order is, Arguments have the higher precedence. The constants tag holds a list of constant tags.

Description. An argument is a variable whose value is retrieved from the command line. An argument can be marked as "required", in which case it must be specified. If it is not required, a default value can be specified, and if not, and the argument was not specified in the command line, it will be assigned a value of an empty string. Arguments are defined inside a variables tag at the top level of the DepFile.

<variables>
	<argument name="arg1" required="true" />
	<argument name="arg2" default="val2" />
	<argument name="arg3" question="What is the value of 'arg3'?" />
</variables>

If the DepFile "example.dep" where to declare the above arguments, then the DepFile can be executed as follows:

prompt> <emphasis>aviate.exe example.dep arg1=val1 arg2=someval2</emphasis>

You can use the question parameter to specify a question to be asked to the user if the value of the parameter was not specified in the command line interface. The "question" parameter is optional, and an input question will be asked only if the parameter was not sent as a command line argument.

Description. Properties are variables that are declared in a Property File. A Property File is an INI-like file divided into sections, and its variables are referred to in the format section_name.variable_name. An example Property File:

[ftp]
username = me
password = mine

[mysql]
host = 127.0.0.1

Arguments are defined inside the same variables tag as Arguments. The precedence of Arguments overrides that of properties, so an argument named ftp.username would override a property variable named username in section ftp. Furthermore, Property Files declared at the end have precedence over property files defined earlier that have variables with the same fully qualified name.

<variables>
	<properties file="prop1.cfg" />
	<properties file="prop2.cfg" />
</variables>

Description. Constants are a way to define named values inside the DepFile, and to refer to them in other parts of the DepFile. Contrary to Arguments and Variables, the value of a constant is specifically specified in the DepFile, and there are a number of pre-defined constants. The constants tag holds a list of constant tags.

<constants>
	<constant name="CONFIG_FILE_NAME" value="main.cfg" />
	<constant name="INSTALL_DESTINATION" value="/var/www" />
</constants>

Description. Allowed characeters in constant names are letters, numbers, dots, underscores and dashes. Constants are evaluated by prefixing the constant name with #{ and postfixing it with }. An example constant:

<constants>
	<constant name="CONFIG_FILE_NAME" value="main.cfg" />
</constants>

To evaluate the constant defined above:

<fs:copy source="local" destination="ftp_server" from="#{CONFIG_FILE_NAME}" to="/var/www" />

For a list of the pre-defined constants, see the Pre-Defined Constants appendix.

Description. All of Aviate's commands are server-aware, and all run on zero or more servers. A command that executes on zero servers is said to be a virtual command, an example of which is the echo command which merely prints on the screen. A command that executes on one server is said to have a destination of that server; an example of which is fs:delete, a command which allows you to delete a file or directory from a filesystem on a destination server. A command that executes on two servers is said to have a source and a destination; an example of which is fs:copy, with which you can copy a file or directory from a source to a destination server's filesystem. The following are examples of how you can define servers:

<servers>
	<server:local id="local" root="/tmp/" />
	<server:mysql id="db_server" host="127.0.0.1" username="root" password="rootpass" />
	<server:subversion id="svn_server" repository_path="http://127.0.0.1/trunk" />
	<server:ssh os="linux" id="ssh_server" host="127.0.0.1" username="root" password="rootpass" />
</servers>

A server is a representation of a machine, which has an operating system of some platform running on it. For example, a machine running Windows 98 would be identified by Aviate as a Server running the 9x operating system on the windows platform. Additionally, a server can either be local or remote. There can only be one local server which represents the current machine running Aviate. Aviate comes with a number of pre-defined Servers, and support for Servers is planned to grow with time. Besides the local server which represents the local filesystem of the machine running Aviate, there are other filesystem servers, namely FTP, SFTP and SSH servers. Other Servers include SVN, a version control Server, MySQL, a SQL Server, and an Rsync Server. And next are three commands that use zero servers, one server, and two servers, respectively:

<echo text="creating a database and copying a file" />
<db:create destination="db_server" name="test_database" />
<fs:copy source="local" destination="ssh_server" from="main.cfg" to="/var/www/" />

Description. A FileSet is a definition of a number of rules that declare match names against files or directories. These matches can be used by some functions to filter their operation. For example, a fs:copy command may exclude a number of files or directories who are matched by the definition in a FileSet. An example declaration of a FileSet in a DepFile is:

<fileset name="set1">
	<match parent="/var/www/uploads" />
	<match parent="/var/www/" name="(.*)\.pyc" />
	<match parent="/var/www/" name="log" type="directory" />
</fileset>

A FileSet is declared as a child to a Command. Not all commands support FileSet children. An example use of a FileSet:

<compress source="local" destination="local" from="/var/www" to="/tmp/test.tar.gz" excludes="set1">
	<fileset name="set1">
		<match name="(.*)\.pyc" />
	</fileset>
</compress>

Description. A match entry is a condition that is applied to each file or directory. Each entry can consist of up to three conditions; parent, name or type. If more than one condition is specified, they are ANDed together. The "parent" condition is a regular expression that is applied against the parent directory of the current item, whether it is a file or directory. The "name" condition is a regular expression that is applied against the name of the current item, whether it is a file or directory. The "type" condition restricts applying the match to either a "file or "directory".

<fileset name="set1">
	<match parent="/var/www/uploads" />
	<match parent="/var/www/" name="(.*)\.pyc" />
	<match parent="/var/www/" name="log" type="directory" />
</fileset>

Description. A target is the main action you want to perform, like installing a new application or updating an existing one. When you execute a DepFile, you must specify the name of the target to execute. A target can depend on other targets, in which case before execution begins, Aviate takes care of resolving the dependency between Targets to decide on the order of their execution. A DepFile must define at least one Target.

<targets>
	<target name="target_1" >
		<!-- ... -->
	</target>
	<target name="target_2" depends="target_1" >
		<!-- ... -->
	</target>
	<target name="target_3" >
		<!-- ... -->
	</target>
</targets>

Description. A Target is a collection of Tasks that represents a unit of execution. A target is the main action you want to perform, like installing a new application or updating an existing one. When you execute a DepFile, you must specify the name of the target to execute. A target can depend on other targets, in which case before execution begins, Aviate takes care of resolving the dependency between Targets to decide on the order of their execution. A DepFile must define at least one Target.

Description. A Task is a grouping of Commands that share a common goal, or describe a single phase of execution. Executing a Target leads to the execution of all of its tasks; in sequential order with regards to Task dependency. Aviate takes care of resolving the dependency between Tasks to decide on the order of their execution. A target must contain at least one Task. Each Task has a unique name that identifies.

<targets>
	<target name="target_1" >
		<task name="task_1" >
			<!-- ... -->
		</task>
		<task name="task_2" depends="task_1" >
			<!-- ... -->
		</task>
		<task name="task_3" >
			<!-- ... -->
		</task>
	</target>
</targets>

Optionally, you can specify the name of an SSH server to chain a Task to. Chaining means that this task will be executed locally on the SSH server; the DepFile will be uploaded, and this task will be executed by another Aviate instance that should have been installed on that SSH server.

Description. A collection of entries.

<list name="list1">
	<entry name="value1" />
	<entry name="value2" />
</list>

Description. An entry in a List or Dictionary. If used in a List, the value only needs to be specified. If used in a Dictionary, both the name and value must to be specified.

Description. A collection of key/value pairs.

<dictionary name="list1">
	<entry name="key1" value="value1" />
	<entry name="key2" value="value2" />
</dictionary>

Description. A FilterChain is an ordered list of Filters that is used to apply it on a stream of data. An example FilterChain:

<filterchain name="filter1">
	<regexfilter pattern="DB_USER" replace="${database.user}" ignoreCase="false" />
	<regexfilter pattern="DB_PASSWORD" replace="${database.password}" />
</filterchain>

Description. A Regular Expression filter to replace a pattern with a value in a stream of data.

<filterchain name="filter1">
	<regexfilter pattern="DB_USER" replace="${database.user}" ignoreCase="false" />
	<regexfilter pattern="DB_PASSWORD" replace="${database.password}" />
</filterchain>

Description. A Local server represents the local machine running Aviate. Many commands are performed against the Local server. For example, when you copy a file from your computer to a web hosting account through SSH; you're copying a file from the Local server to an SSH server. There must be one and only one Local server defined. An example definition:

<servers>
	<server:local id="local" root="/var/www" />
	<server:ssh os="linux" id="srv" host="a.com" username="root" password="${password}" />
</servers>

To copy a file from the local to the remote SSH server as defined above:

<fs:copy source="local" destination="myserver" from="config.ini" to="/var/www" />

Description. Defines an FTP server.

Description. Defines an SFTP (SSH over FTP) server.

Description. Defines an SSH server. An SSH server is similar to an SFTP server, with an added capability of executing system commands on it. To login to an SSH server, you either have to specify a username and password pair, or the path to a certificate file (along with its passphrase if necessary).

Description. Defines a remote Subversion server. The repository_path could either be the root of the repository, or a specific directory inside it. For example, it can both be "http://example.com/svn/project" or "http://example.com/svn/project/dir1/dir2". Eitherway, when you want to checkout, you specify the directory you want to checkout relative to the repository path, so the checkout URL is formed by appending the repository path to the checkout directory.

<servers>
<server:subversion id="svn" repository_path="http://source.vimov.com/svn/aviate/trunk" />
</servers>

If you then wanted to checkout the contents of trunk, you could:

<vc:checkout source="aviate_svn" destination="local" from="/" to="/tmp" />

Description. Defines a MySQL server. Note that in most server configurations, MySQL cannt be accessed except through a local connection from its server. To overcome this limitation, you can either run Aviate on the MySQL server, or better yet, use Chaining over SSH.

Description. Defines an Rsync server; a server running Rsync in daemon mode. This is separate from using Rsync over SSH, to which you do not need to define an Rsync server.

Description. Syncs a local or remote directory to a local or remote server one using Rsync. Both the source and destination cannot be remote servers; one has to be Local. You must have Rsync installed unless you are using a binary distribution (on Windows, Aviate is packaged with Rsync).

<fs:rsync
	source="local"
	destination="ssh_server"
	from="${working_dir}/"
	to="#{SITE_DIR}"
	options="opt"
>
	<dictionary name="opt">
		<entry name="-r"/>
		<entry name="--delete"/>
		<entry name="--exclude" value=".svn" />
		<entry name="--exclude" value="source/files" />
	</dictionary>
</fs:rsync>

Both the source and destination cannot be remote servers; one has to be Local.

Description. Copy a file or directory to a destination server. You can copy files and directories on the Local server, from the Local server to a remote server (like an SSH server), or from a remote server to the Local server. Supported servers are Local, FTP, SFTP, and SSH. You cannot copy between two remote servers.

<fs:copy source="local" destination="ssh_server from="config.ini" to="/var/www/" replace="true" />

Description. Delete a file or directory. The Delete operation can be applied to a Local, an FTP, an SFTP, or an SSH server.

<fs:delete destination="ssh_server path="/var/www/cache" contents_only="true" />

An example that uses an exclude list to skip directories:

<fs:delete destination="local" path="a" recursive="true" />
<fs:mkdir destination="local" path="a/1/b1" recursive="true" />
<fs:mkdir destination="local" path="a/2/b1" recursive="true" />
<fs:mkdir destination="local" path="a/2/b2" recursive="true" />
<fs:mkdir destination="local" path="a/3/b1" recursive="true" />
<fs:delete destination="local" path="a" recursive="true" excludes="list1">
	<fileset name="list1">
		<match parent="1" />
		<match parent="2" name="b2" />
	</fileset>
</fs:delete>

Description. Change the permissions of a file or directory. The Chmod operation can be applied to a Local, an FTP, an SFTP, or an SSH server.

<fs:chmod destination="ssh_server path="/var/www/upload" permissions="rwxr-xr-x" recursive="true" />

Description. Change the owner or group of a file or directory. The Chmod operation can be applied to a Local or an SSH server, and cannot be applied to Windows servers.

<fs:chown destination="ssh_server path="/var/www/upload" owner="www-data" group="www-data" />

Description. Create a directory. If the directory already exist, no error will be reported. The operation can be applied to a Local, an FTP, an SFTP, or an SSH server.

<fs:mkdir destination="ssh_server path="/var/www/upload" mode="rwxr-xr-x" />

Description. Compress a file or directory. The compressed file can be a ZIP, a TAR, a GZipped TAR or a BZipped TAR. The source and destination must both be the Local server, and cannot be a remote server. The extension of the target file will decide the compression type; it can be ".zip", ".tar", ".tar.gz" and ".tar.bz2".

<fs:compress source="local" destination="local" from="/var/www" to="latest.tar.gz" />

Description. Decompress a file. The compressed file can be a ZIP, a TAR, a GZipped TAR or a BZipped TAR. The source and destination must both be the Local server, and cannot be a remote server. The extension of the file will decide the compression type; it can be ".zip", ".tar", ".tar.gz" and ".tar.bz2".

<fs:decompress source="local" destination="local" from="latest.tar.gz" to="." />

Description. Renames a file or directory on the same server.

<fs:rename destination="ssh_server from=".htaccess.production" to=".htaccess" replace="true" />

Description. Syncs a local directory to an FTP/SFTP server based on the timestamp.

Description.  Create a new database at a MySQL server.

<db:create destination="mysql_server" name="testdb" />

Description.  Drop a database from a MySQL server.

<db:drop destination="mysql_server" name="testdb" />

Description.  Execute one or more SQL statements. The destination server must be a MySQL server.

<db:sql destination="mysql_server" statements="stats1" database="testdb" >
	<list name="stats1">
		<entry value="create table test (id INT, data VARCHAR(100));" />
		<entry value="insert into test values ('1', 'one');" />
		<entry value="insert into test values ('2', 'two');" />
	</list>
</db:sql>

Description. Dump to a file from a MySQL server. Uses the mysqlump binary from the MySQL client distribution. You can specify the same command line options you pass to the mysqldump binary through an options dictionary.

<db:mysqldump source="mysql" destination="local" to="o.sql" databases="dl" tables="tl" options="od" >
	<list name="dl">
		<entry value="blog"/>
	</list>
	<list name="tl">
		<entry value="posts"/>
		<entry value="comments"/>
		<entry value="users"/>
	</list>
	<dictionary name="od">
		<entry name="--xml"/>
	</dictionary>
</db:mysqldump>

Description. Import from a file to a MySQL server. Uses the mysqlimport binary from the MySQL client distribution.

<db:mysqlimport source="local" destination="mysql_server" from="dump.sql" to="testdb" />

Description. Checkout from a Version Control server. The server must be a Subversion server.

<vc:checkout source="svn_server" destination="local" from="." to="/tmp" />

Description. Export from a Version Control server. The server must be a Subversion server.

<vc:export source="svn_server" destination="local" from="." to="/tmp" />

Description. Executes a command on either the local server or a remote SSH server. It is not possible to execute commands on FTP or SFTP servers.

<system:execute
	destination="local"
	command="ls /tmp"
	verbose="true"
	success_if="success_list"
	fail_if="fail_list"
>
	<list name="success_list">
		<entry value="0" />
	</list>
</system:execute>

Description. Download a file from the web to a Local server.

<web:download destination="local" from="${url1}" to="/tmp/download.zip" replace="true" />
<web:download destination="local" from="${url2}" to="/tmp" replace="true" />

Description. The Web Browser allows you to simulate a traditional browser session. It allows you to pass data to pages, validate the responses using a variety of ways, and it carries the cookies between the requests. Each session, represented by an instance of web:browser, consists of one or more web:request.

Description. Defines a request to send to a web server. The request can be either a GET or POST request, and it can carry data if needed. If a response is returned, then the request is assumed to have succeeded by default. Further constraints can be imposed to specify the certain cases at which the request should be assumed to have succeeded, by utilizing the HTTP response code, the body of the response or the returned cookies.The following example demonstrates automating the web portion of installing Wordpress:

<web:browser>
	<web:request
		url="${sie_url}/wp-admin/install.php?step=2"
		method="post"
		data="post_data"
		valid_codes="vcodes"
 >
		<dictionary name="post_data">
			<entry name="weblog_title" value="${title}" />
			<entry name="admin_email" value="${email}" />
			<entry name="blog_public" value="${public}" />
		</dictionary>
		<list name="vcodes">
			<entry value="200" />
		</list>
	</web:request>
</web:browser>

Description. Print a text on the terminal. An example to print pre-defined constants:

<t:echo text="Pre-defined Constants" />
<t:echo />
<t:echo text="Date: #{YEAR}-#{MONTH}-#{DAY}" /> #{CWD}, #{APP_DIR}, #{TEMP}, " />
<t:echo text="Time: #{HOUR}:#{MINUTE}:#{SECOND}:#{MICROSECOND}" />
<t:echo text="Platform: #{PLATFORM}, #{OS}" />
<t:echo text="DepFile: #{DEPFILE_DIR}, #{DEPFILE_NAME}" />
<t:echo text="CWD: #{CWD}" />
<t:echo text="APP_DIR: #{APP_DIR}" />
<t:echo text="TEMP: #{TEMP}" />

A two-state logical datatype. Its allowed values state values are "true" and "false", or "1" and "0".

An unsigned number datatype.

A string whose length is zero characters long or more.

A string whose length is one characters or more.

A Variable Name is a name that is used to identify a class of similar tags, like a list of Servers. A Variable Name must be unique in its scope of definition, but not globally unique. For example, since two Servers are in the same class, no two Servers may have the same name. However, a Server may have the same name as a Constant, since they are two objects of a different class.

Allowed characeters in a Variable's name are letters, numbers, dots, underscores and dashes.