The plain text gardener utility

(*

Author: R. J. Cano.
Written on Sat Dec 29 2012, 02:09 VET.

THIS PROGRAM IS FREE SOFTWARE AND GOES WITHOUT ANY WARRANTY WHATSOEVER.
RELEASED UNDER THE TERMS OF THE GNU GPLv3.0 LICENSE.

For details please see: http://www.gnu.org/licenses/gpl-3.0.txt

*)

program plainTextGardener;

const
  TAB=#9;
  WhiteSpace=#32;
  delim=':';
  definedFields=4;
  fieldSize_offsets=6;
  fieldSize_data=16;
  interFieldSize=3;
  fieldBound=2*(fieldSize_offsets+fieldSize_data)+(definedFields-1)*interFieldSize;

fieldSize : array [1..definedFields] of byte= (fieldSize_offsets, fieldSize_data, fieldSize_data, fieldSize_offsets);

var
  f: text;
  s: string;
  i,j,k,l,t: byte;

begin
  assign(f, paramstr(1));
  reset(f);
  while (not eof(f)) do begin
      readln(f,s);
      for t:= 1 to length(s) do begin (*Ignores the TABS*)
    if (s[t]=TAB) then s[t]:= WhiteSpace;
      end;
      i:= 1; (* Current field *)
      if (length(s) < fieldBound) then begin
    j:=0; (* How many chars before delim *)
    k:=0; (* Cursor *)
    while ( (i <= definedFields) and (k<length(s)) ) do begin
      k:= k + 1;
      if ((s[k]=delim)) then begin
        (* Also: It would work properly to subtract "j" directly from fieldBound *)
        for l:= 1 to (fieldSize[i]-j) do write(' ');
        for l:= 1 to interFieldSize do write(' ');
        i:= i + 1;
        j:=0;
      end else begin
        write(s[k]);
        j:= j + 1;
      end;
    end;
    writeln();
      end else begin
    writeln(s);
      end;
  end;
  close(f);
end.