The module markfilt.e provides the procedure filter_selection for filtering selected text. Define a global procedure that accepts a string and returns a string. Then pass the name of the procedure to the filter_selection procedure.

The following batch program converts the marked text into hexadecimal ASCII codes. Each hexadecimal ASCII code is separated by a comma. One possible use of this function could be to convert a binary font file into hexadecimal ASCII codes to be compiled into a C program.

#include "slick.sh"
 
_str hex_filt(string);
 
defmain() 
{
    if (_select_type()=="" ) {
       message(get_message(TEXT_NOT_SELECTED_RC));
       return(TEXT_NOT_SELECTED_RC);
    }
    // Underscores must be converted to dashes.
    return(filter_selection(hex_filt));
}
 
_str hex_filt(string)
{
    line="";
    for (i =1;i<=length(string);++i) {
       line=line:+dec2hex(_asc(substr(string,i,1))):+",";
    }
    return(line);
}