strsubk
        
        strsubk — 
      Extract a substring
          
       
      
        
        Description
        
      Return a substring of the source string. strsubk runs both at init and
      performance time.
    
       
      
        
        Syntax
        Sdst strsubk Ssrc, kstart, kend
       
      
        
        Performance
        
      kstart
      -- start position in Ssrc, counting from 0.
      A negative value means the end of the string.
    
        
      kend
      -- end position in Ssrc, counting from 0.
      A negative value means the end of the string. If kend is less than
      kstart, the output is reversed.
    
       
      
      
        
        Credits
        
      
        
          
            | Author: Istvan Varga | 
          
            | 2006 |