Defining the Data Criteria for a Data Type

The DATA_CRITERIA definition defines the criteria used to assign an object type to a file or directory.

You can use the criteria show in Table 13-3 for object typing.

Table 13-3 DATA_CRITERIA Criteria and Descriptions

Criteria	Description
File name	The file name must match a specified pattern. Use the NAME_PATTERN field.
File location	The path must match a specified pattern. Use the PATH_PATTERN field.
File contents	A specified portion of the file's contents must match specified data. Use the CONTENT field.
File mode	The file must possess the specified permissions (read, write, execute, directory). Use the MODE field.
Symbolic links	The typing is based on the file to which the object is linked.

You can use more than one criteria for a data type. However, you should not use the NAME_PATTERN and PATH_PATTERN criteria in the same data type.

Name-Based Data Types

Use the NAME_PATTERN field to specify the naming requirement. The field value can include the following wildcards:

?--matches any single character

*--matches any sequence of characters (including a null string)

[cc...]--matches any of the characters (c) enclosed in brackets

[c-c]--matches any of the characters in the range c through c

Examples

• The following data type definition creates a data type based on the file name. The file name must begin with QS and end with .doc.

  	DATA_ATTRIBUTES QS_Doc
   	{
   		DESCRIPTION				This file contains a document for the QS \
   									project.
   		ICON						Word_Doc
   		ACTIONS					Open
   	}
  
   	DATA_CRITERIA QS_Doc_Criteria
   	{
   		NAME_PATTERN				QS*.doc
   		DATA_ATTRIBUTES_NAME 	QS_Doc
   	}

• The following definition creates a data type for directories named Demo_n where n is 0 through 9.

  	DATA_ATTRIBUTES Demo_directory
   	{
   		DESCRIPTION				This is a directory. Double-click to open it.
   		ICON						Demo
   		ACTIONS					OpenInPlace,OpenNewView
   	}
  
   	DATA_CRITERIA Demo_directory_criteria
   	{
   		NAME_PATTERN						Demo_[0-9]
   		MODE					 				d
   		DATA_ATTRIBUTES_NAME			Demo_directory
   	} 

Location-Based Data Types

Use the PATH_PATTERN field to specify the path. You can use the same wildcard characters as with NAME_PATTERN.

For example, the following data type uses a criteria based on path.

DATA_ATTRIBUTES Project_Graphics
 {
 	DESCRIPTION			Graphics file for the QS project. Double-click the \
 							icon to see the graphic.
 	ICON					QSgraphics
 }
 DATA_CRITERIA Project_Graphics_Criteria
 {
 	DATA_ATTRIBUTES_NAME			Project_Graphics
 	PATH_PATTERN						*/projects/QS/graphics/*
 }

Data Types Based on Name and Location

To create a data type based on both file name and location, include the name in the PATH_PATTERN value. You cannot use both NAME_PATTERN and PATH_PATTERN in the same criteria definition.

Examples

• The QS_Source_Files data type defined below applies to all files named appn.c, where n= 1 through 9, located in subdirectories of */projects/QS.

  	DATA_ATTRIBUTES QS_Source_Files
   	{
   	   ...
   	}
   	DATA_CRITERIA QS_Source_Files_Criteria
   	{
   		PATH_PATTERN						*/projects/QS/*/app[1-9].c
   		DATA_ATTRIBUTES_NAME			QS_Source_Files
   	}

• The following data type applies to all files in the directory /doc/project1 named chnn.xxx where n is 0 through 9, and xxx is any three-character file- name suffix.

  	DATA_ATTRIBUTES ChapterFiles
   	{
   		DESCRIPTION			Chapter file for the project document.
   		ICON					chapter
   		ACTIONS				Edit,Print
   	}
   	
   	DATA_CRITERIA Chapter_Criteria
   	{
   		PATH_PATTERN						/doc/project1/ch[0-9][0-9].???
   		DATA_ATTRIBUTES_NAME			ChapterFiles
   	}

Using File Modes as a Typing Criteria

Use the MODE field to specify the required permissions.

Mode criteria are usually used in combination with name-based, location-based, or content-based data typing. They allow you to limit a data type to a file or directory, or to specify the required read, write, and execute permissions.

The MODE field can include logical operators (Table 13-4) and characters (Table 13-5).

Table 13-4 MODE Field Logical Operators and Descriptions

Operator	Description
!	Logical operator NOT
&	Logical operator AND
|	Logical OR

Table 13-5 MODE Field Characters and Descriptions

Character	Description
f	The data type applies only to files
d	The data type applies only to directories
r	The file is readable by any user
w	The file is writable by any user
x	The file is executable by any user
l	The file is a link

The default for a particular mode is that the mode does not matter.

Examples

• The following mode fields restrict the data type as described:

  f&!w--read-only files

  !w--read-only files and directories

  f&x--executable files

  f&r&x--files that are both writable and executable

  x|!w--files that are executable or read-only

• The following data type definition creates an data type for read-only, non-executable files whose file names follow the naming convention *.doc. It assumes that a View action has been defined for the data type.

  	DATA_ATTRIBUTES ReadOnlyDocument
   	{
   		ICON						read_only
   		DESCRIPTION				This document is not writable. Double- \
   									clicking runs your editor with a \
   									read-only copy of the file.
   		ACTIONS					View
   	}
  
   	DATA_CRITERIA ReadOnlyDocument_Criteria
   	{
   		NAME_PATTERN						*.doc
   		MODE									!d&!x&!w
   		DATA_ATTRIBUTES_NAME			ReadOnlyDocument
   	}

Content-Based Data Typing

Use the CONTENT field to specify data typing based on the content of the file. Content-based data typing can be used in combination with name- or location-based data typing.

The typing can be based on either string or numeric content for files. The first byte in the file is numbered 0.

• For string content of a file, use the syntax:

  	CONTENT  starting_byte string string
  

• For number content of a file, use the syntax:

  	CONTENT starting_byte byte number
   	CONTENT starting_byte short number
   	CONTENT starting_byte long number
  

• For the contents of a directory, use the syntax:

  	CONTENT 0 filename "file_name"

  Use standard C notation for octal (leading o) and hexidecimal (leading oX) numbers.

  ---

  Note -

  Use of content-based data typing will result in slower system performance. Wherever possible, use name- and location-based typing instead.

  ---

  For example, the following data type, Writable_Wingz, applies to all files with write permission containing the string WNGZ at the beginning of the file.

  	DATA_ATTRIBUTES Writable_Wingz
  	{	
   		...
   	}
  
   	DATA_CRITERIA Writable_Wingz_Criteria
   	{
   		CONTENT						0 string WNGZ
   		MODE							w&!d
   		DATA_ATTRIBUTES_NAME	Writable_Wingz
   	}

To Create a Data Type with Several Independent Criteria

You can create a data type with several independent criteria--that is, the file is assigned to the data type if it meets either (or both) of the criteria.

1. Create the DATA_ATTRIBUTES definition for the data type.

2. Create a DATA_CRITERIA definition for each criteria.

   Use the DATA_ATTRIBUTES_NAME field to connect each criteria to the same DATA_ATTRIBUTES definition.

   For example, the following definitions create the Mif data type. Typing is based on name or content.

   DATA_ATTRIBUTES Mif
   {
    	ICON								Frame
    	ACTION_LIST						Open,Print
    }
   
    DATA_CRITERIA Mif_Name_Criteria
    {
    	DATA_ATTRIBUTES_NAME				Mif
    	NAME_PATTERN							*.mif
    }
   
    DATA_CRITERIA Mif_Content_Criteria
    {
    	DATA_ATTRIBUTES_NAME		Mif
    	CONTENT							1 string MIFFile
    }