*********
          *
          * This definition works on files that are produced by the
          * the AmigaDOS LIST command.  It will EDIT the file listed
          * on the current cursor line if it's a file and will
          * DIRECTORY it if it's a directory.
          *
          * Trick    Searches backwards for the string 'Directory "' to
          *          find the full path for the selected file.  Then sets
          *          ENVIRONMENT 9 to that value.  If the path ends in a
          *          directory name which is not terminated by a slash (/)
          *          then inserts a slash.
          *
          *          Note if the 'Directory "' string is not found then the
          *          file is assumed to be in the current directory. ie.
          *          no path
          *
          *          Then if the word following the selected filename is
          *          'Dir' then sets ENVIRONMENT 8 to 'dir' otherwise sets
          *          it to 'edit'.
          *
          *          Then executes a line derived from ENVIRONMENTs 8 and 9
          *          and the selected file name.
          *
          *********

DEF s-f4 = [store mark] [unmark]
DEF s-f4 + [store cursor]
DEF s-f4 + [if] [locate] 'Directory "' 'c-' [right 11]
DEF s-f4 +   [if char in] '="'                  * no directory name
DEF s-f4 +     [execute] 'set envir 9 \'\''     * clear environment variable
DEF s-f4 +   [else]
DEF s-f4 +     [mark char]                      * otherwise, copy dir name
DEF s-f4 +     [end char] '-"' [left]
DEF s-f4 +     [if char in] '-:/'               * if last char in name is not :
DEF s-f4 +       [right] [insert mode] '/'      * then append /
DEF s-f4 +       [left]
DEF s-f4 +     [end if]
DEF s-f4 +     [mark char]
DEF s-f4 +     [command cursor] [delete line]
DEF s-f4 +     'set envir 9 \'' [import mark]   * copy name to command line
DEF s-f4 +     [end line] '\''
DEF s-f4 +     [execute]                        * set env 9 to dir name
DEF s-f4 +   [end if]
DEF s-f4 + [else]                               * dir name not found
DEF s-f4 +   [execute] 'set envir 9 \'\''       * make it blank
DEF s-f4 + [end if]
DEF s-f4 + [data cursor]
DEF s-f4 + [recall cursor] [begin line] [unmark]
DEF s-f4 + [mark char] [end word] [left] [mark char]
DEF s-f4 + [tab word]
DEF s-f4 + [if string is] 'Dir'                 * dir on current line
DEF s-f4 +   [execute] 'set env 8 \'dir \''     * env 8 is dir command
DEF s-f4 + [else]
DEF s-f4 +   [execute] 'set env 8 \'edit \''    * otherwise, it's a file, ie. edit command
DEF s-f4 + [end if]
DEF s-f4 + [command cursor] [delete line]
DEF s-f4 + [envir 8] [envir 9] [import mark]    * execute the combination of
DEF s-f4 + [data cursor]                        * command, dir, and file name
DEF s-f4 + [recall mark] [forget mark]
DEF s-f4 + [recall cursor] [forget cursor]
DEF s-f4 + [down]
DEF s-f4 + [execute]