In order to be able to insert the values of some environment variables during the evaluation process, the Document Generator provides several functions that may be used in entity definitions or templates:
&base(file);      
removes path information and extension from the file 
specification.       
Example: 
&base(/home/bscw/www/faq.dtm); results in faq
&rel(path); generates a 
relative path name out of an absolute one. The generated path name is relative 
to the document that will be generated (set in the evaluation parameter 
document). 
Example: If the expression 
&rel(/Images); is used in a template, that generates the 
document /faq/index.htm, this expression will be evaluated to 
../Images. If one uses the same expression in a template that 
generates the document /faq/question/ install.htm, it will be 
evaluated to ../../Images. 
&size(file, [B|K|M|G]); 
returns the size of a file in bytes, kilobytes, megabytes or 
gigabytes, depending on the value of the second parameter.    
Example: &size(/Download/bscw34.exe, M); results in 
8.43
&date(format);    
returns the current date and time. The following directives may 
be used in the format string. They are shown here without 
the optional field width and precision specifications. 
| 
       Directive  | 
    
       Meaning  | 
| 
       
  | 
    
       Locale’s abbreviated weekday name.  | 
| 
       
  | 
    
       Locale’s full weekday name.  | 
| 
       
  | 
    
       Locale’s abbreviated month name.  | 
| 
       
  | 
    
       Locale’s full month name.  | 
| 
       
  | 
    
       Locale’s appropriate date and time representation.  | 
| 
       
  | 
    
       Day of the month as a decimal number [01, 31].  | 
| 
       
  | 
    
       Hour (24-hour clock) as a decimal number [00, 23].  | 
| 
       
  | 
    
       Hour (12-hour clock) as a decimal number [01, 12].  | 
| 
       
  | 
    
       Day of the year as a decimal number [001, 366].  | 
| 
       
  | 
    
       Month as a decimal number [01, 12].  | 
| 
       
  | 
    
       Minute as a decimal number [00, 59].  | 
| 
       
  | 
    
       Locale’s equivalent of either AM or PM.  | 
| 
       
  | 
    
       Second as a decimal number [00, 61].  | 
| 
       
  | 
    
       Week number of the year (Sunday as the first day of the week) as a decimal number [00, 53]. All days of a year preceding the first Sunday belong to week 0.  | 
| 
       
  | 
    
       Weekday as a decimal number [0 (Sunday), 6].  | 
| 
       
  | 
    
       Week number of the year (Monday as the first day of the week) as a decimal number [00, 53]. All days of a year preceding the first Monday belong to week 0.  | 
| 
       
  | 
    
       Locale’s appropriate date representation.  | 
| 
       
  | 
    
       Locale’s appropriate time representation.  | 
| 
       
  | 
    
       Year without century as a decimal number [00, 99].  | 
| 
       
  | 
    
       Year with century as a decimal number.  | 
| 
       
  | 
    
       Time zone name (or empty string if no time zone exists).  | 
| 
       
  | 
    
       The character 
‘  | 
Example: On October 10, 2005 the result of 
&date(%B %Y); is October 2005.