% unix-pas.ch -*-mode: change; webfile: crudetype.web version 3.01;-*-
% UNIX changes by Peter King for Berkeley Pascal
% modified by RMD for Crudetype version 2 and for v3
%
%
% COPYRIGHT ( C ) P.King,  Heriot-Watt University, 1988.
%
% Permission is given to any person to make and distribute copies of this
% software, subject to the following conditions:
%
% 1. All copies of the software must carry an exact copy of this notice.
%
% 2. This software is distributed free of charge, "AS IS" with absolutely no
% guarantee of performance. Any persons receiving or using this software must do
% so entirely at their own risk. Neither the authors nor their institutions
% accept any liability for any defects of this software, or for any consequential
% loss or damage however caused.
%
% 3. Any person who changes this software must clearly mark it as modified and
% add a note describing the changes made.
%

% WEAVE: print changes only
@x  Module 0; Lines 42 -- 42
\pageno=\contentspagenumber \advance\pageno by 1
@y
\pageno=\contentspagenumber \advance\pageno by 1
\def\title{Crudetype for {\mc UNIX }  }
@z

@x  Module 4; Lines 213 -- 213
@d banner=='This is Crudetype, Version 3.01, copyright, experimental'
@y
@d banner=='This is Crudetype, Version 3.01, copyright, experimental UNIX'
@z

% UNIX writeln moves you down a line
% Suppress unwanted control-M's at ends of lines
@x  Module 6; Lines 242 -- 242
  @<Set initial values@>
@y
  @<Set initial values@>
  setpaths; { set up the correct search path for fonts }
  wl_feed_dist := 1 ;
  wl_does_cr := true ;
@z

% add variables for runtime arguments, and to suppress all the non-error
% information messages
% stdin is not yet used, but is a handle for an extension to read from
% input ( a UNIX pipe )
@x  Module 7; Lines 253 -- 253
  in_i, in_j :integer; {loop index for initializations}
@y
  in_i, in_j :integer; {loop index for initializations}
  stdin : boolean; { read from standard input }
@z

% Change the types
@x  Module 11; Lines 310 -- 312
@<Types...@>=
  byte = 0..255 ;
  i_word = -max_half-1 .. max_half ;
@y
@<Types...@>=
  byte = 0..255 ;
  bite = -128..127 ; { signed ! }
  i_word = -max_half-1..max_half ;
@z

@x  Module 12; Lines 334 -- 336
@d Q_string == packed array[ first..last:integer] of char
@d be_string(#) == set_string( #, buffer)
@d set_j_to_length == j := last
@y
@d Q_string == fix_string
@d be_string(#) == hack := # ; set_string( hack, buffer)
@d set_j_to_length == j := max_string
@d first = 1
@z

@x  Module 14; Lines 360 -- 361
@<Lowest...@>=
  {Declare |parse_file|}
@y
@<Lowest...@>=
  procedure  parse_file( name: var_string; var dir, nam, ex: var_string) ;
  var p,r,s: s_ptr ;
  begin
    dir := blank; nam := blank; ex := blank;
    s := name.len ;
    if ( s>0) then begin
      p := s_search( name, '/', -s);
      if ( p>0) then substring( dir, name, 1, p) ;
      r := s_search( name, '.', -s);
      if ( r>p) then substring( ex, name, r, s-r+1)
      else r := s +1 ;
      substring( nam, name, p+1, r-p-1) ;
    end;
  end;
@z

@x  Module 16; Lines 408 -- 408
@d print_ln ==write_ln(printfile )
@y
@d print_ln == write_ln(printfile );
  if inspection then flush(printfile )
@z

% Changes to incorporate UNIX conventions
% lower case file names, default to putting the .lpr file in the
% same directory as the .dvi file
@x  Module 18; Lines 429 -- 436
@d block_length = 512
@d same_dir == false

@<Set init...@>=
  be_string( '.DVI' ) ; dvi_def := buffer ;
  be_string( 'TEX$FONTS:.TFM' ) ; tfm_def := buffer ;
  be_string( 'TEX$GF:.&DGF' ) ; raster_def := buffer ;
  be_string( '.PRI' ) ; print_ex := buffer ;
@y

The Unix version of \.{Crudetype} uses ``paths''.

@d block_length = 1
@d same_dir == true

@<Set init...@>=
  be_string( '.dvi' ) ;  dvi_def := buffer ;
  be_string( '.tfm' ) ;  tfm_def := buffer ;
  be_string( '/tex/gfdir/.&Dgf' ) ;  raster_def := buffer ;
  be_string( '.lpr' ) ;  print_ex := buffer ;
@z

% More of the UNIX simple minded view of files.
% but including the (optional) directory search for .tfm files
@x  Module 19; Lines 442 -- 443
@<Lowest...@>=
  {Declare |open_binary|}
@y
@d read_access_mode=4  {``read'' mode for |test_access|}
@d write_access_mode=2 {``write'' mode for |test_access|}

@d close_binary(#)== do_nothing ;

@<Lowest...@>=
  procedure setpaths;
    external;
  function test_access(
    accessmode:integer; filepath:integer;
    var name, realname: fixstring ) : boolean;
    external;
@#
  function open_binary (var f_f: byte_file; name: var_string;
    search_path: integer ): boolean;
  begin
    cur_name := name.data ; real_name := blank.data ;
    if test_access(read_access_mode,search_path, cur_name, real_name) then
    begin
      reset(f_f, real_name);
      be_string( real_name ) ;  name := buffer ;
      open_binary := true
    end
    else
    open_binary := false
  end;
@z

@x  Module 20; Lines 446 -- 446
  rewrite(printfile) ;
@y
  if inspection then
    rewrite(printfile, '/dev/tty' )
  else rewrite(printfile, print_name.data ) ;
@z

@x  Module 21; Lines 452 -- 466
@d get_val( #) == # := s_to_i( #, true)
@d prefix == "/"
@d got_cl == ( command.len > 0)
@d read_command_line( #) == do_nothing

@<Lowest...@>=
  {Declare |read_command_line| }
@#
  procedure get_command ;
  var ss: fix_string ;
  begin
    ss := blank.data ;
    read_command_line( ss) ;
    be_string( ss ) ; command := buffer ;
  end;
@y

Unix \P\ does not supply a command line; instead it chops it up and supplies
the pieces using two predeclared procedures |argc| and |argv|. It seemed to me
that the least messy way to fit this onto the rest of the program is to
re-assemble the command line.

@d get_val( #) == # := s_to_i( #, true)
@d prefix == "-"
@d got_cl == ( argc > 1)
@d read_command_line( #) == do_nothing

@<Lowest...@>=
  procedure get_command ;
  var ss: fix_string ; nn: integer ; tt: var_string ;
  begin
    command := blank ;
    for nn := 1 to argc-1 do begin
      ss := blank.data ;
      argv( nn, ss) ;
      be_string( ss  ) ;  tt := buffer ;
      append( command, tt) ;
      incr( command.len) ;
    end;
  end;
@z

@x  Module 27; Lines 560 -- 572
@ If there was no command line, try to send messages to the user at a
terminal. This requires nonstandard \PASCAL\ constructions to handle the
online interaction. So it may be necessary on some systems to omit the dialog.
First, the \.{DVI} file name.

@<Get \.{DVI} file name and open it@>=
  if can_interact and ( dvi_name.len = 0) then repeat
    ask_prompt('DVI file name? ') ;
    get_name( dvi_name) ;
  until ( dvi_name.len > 0) ;
  if not open_and_ask(dvi_file, dvi_indx, dvi_name, dvi_def, true)
  then abort('Couldnt open DVI file')
    @.Fatal: Couldnt open@>
@y
@ If there was no command line, try to send messages to the user at a
terminal. This requires nonstandard \PASCAL\ constructions to handle the
online interaction. So it may be necessary on some systems to omit the dialog.
First, the (\.{DVI}) file name. This part is altered to use Unix style path
searching.

@d no_file_path=0    {no path searching should be done}
@d font_file_path=3  {path specifier for \.{TFM} files}

@<Get \.{DVI} file name and open it@>=
  if can_interact and ( dvi_name.len = 0) then repeat
    ask_prompt('DVI file name? ') ;
    get_name( dvi_name) ;
  until ( dvi_name.len > 0) ;
  dvi_indx := no_file_path ;
  if not open_and_ask(dvi_file, dvi_indx, dvi_name, dvi_def, true)
  then abort('Couldnt open DVI file')
    @.Fatal: Couldnt open@>
@z

@x  Module 28; Lines 574 -- 577
@ But when we come to open a font file, we merely report a failure:

@<Open font file@>=
  font_ok := open_and_ask (tfm_file, tfm_indx, tfm_name, tfm_def, true) ;
@y
@ When we try to open a font file, we search the path specified by the user's
environment variable before we report a failure:

@<Open font file@>=
  tfm_indx := font_file_path ;
  font_ok := open_and_ask (tfm_file, tfm_indx, tfm_name, tfm_def, true) ;
@z

% Binary file handling
@x  Module 33; Lines 661 -- 671
The main input file is the \.{DVI} file. Logically, this is just a stream of
8-bit bytes, with no record or block structure. However VMS \PASCAL\
apparently cannot handle files of this type; so I have adopted the blocking
scheme (due to D.R.Fuchs) from the VMS \.{DVItype} change file. But a lot of
the code has been rewritten. Some other operating systems use similar
blocking schemes; so this code may possibly work without much change. The
program deals with two binary file variables: |@!dvi_file| is the main input
file that we are printing, and |@!tfm_file| the current font metric file from
which character-width information is being read. Each of these has a name and
a counter, declared here; also a default name (system dependent, and so
declared previously).
@y
The main input file is the \.{DVI} file. Logically, this is just a stream of
8-bit bytes, with no record or block structure. UNIX \PASCAL\ can happily
handle these, except that it treats each byte as a signed quantity, so we do
some fudging to make them unsigned. The program deals with two binary file
variables: |@!dvi_file| is the main input file that we are printing, and
|@!tfm_file| the current font metric file from which character-width
information is being read. Each of these has a name declared here.
@z

% Binary file types
@x  Module 33; Lines 675 -- 676
  @!byte_block=packed array [0..block_length-1] of byte ;
  @!byte_file= packed file of byte_block;
@y
  @!byte_file= file of bite;
@z

%   The filenames used by |test_access| are added here.
@x  Module 34; Lines 685 -- 685
  printfile: text ;
@y
  printfile: text ;
  @!cur_name,@!real_name:fix_string ;
   {external name}
@z

% open_and_ask must pass the search path into open_binary
@x  Module 35; Lines 701 -- 701
      success := open_binary(f_f, name ) ;
@y
      success := open_binary(f_f, name, f_c ) ;
@z

% P. King deleted all the VMS indx stuff, since all the files are (logically)
% read one character at a time. I have re-instated it because it is very
% useful when debugging.
%
@x  Module 38; Lines 745 -- 776
@d get_real(#) == read_real(# @& file, # @& indx)

@<Lowest...@>=
  function read_byte(var f_file: byte_file; var f_indx: integer) : byte;
  begin
    if eof(f_file) then
      warn('End of file' )
    else begin
        read_byte := f_file^[f_indx] ;
        incr(f_indx);
        if f_indx =block_length then begin
            get(f_file );
            f_indx:=0;
          end;
      end;
  end ;

@#
  procedure skip_bytes(var f_file: byte_file; var f_indx: integer; n:integer);
    {discard n bytes from |f_file|}
  begin
    if n < 0 then abort('Skip_bytes called with negative number');
    f_indx := f_indx + n;
    while( f_indx >= block_length) do
      begin
        if eof(f_file) then
          warn('End of file' )
        else get(f_file );
        f_indx := f_indx - block_length ;
      end ;
  end;
    @.Error: End of file@> @.Fatal: Skip_bytes...@>
@y
@d read_real == rr_read_real    {|read_real| is  Unix \PASCAL\ procedure}
@d get_real(#) == read_real(# @& file, # @& indx)

@<Lowest...@>=
  function read_byte(var f_file: byte_file; var f_indx: integer) : byte;
  var x:bite;
  begin
    if eof(f_file) then begin
      warn('End of file' ) ;
      read_byte := 0 ;     { return some value }
    end
    else begin
      read(f_file,x);
      if x < 0 then read_byte := x + 256
      else read_byte := x ;
      incr(f_indx);
    end;
  end;

@#
  procedure skip_bytes(var f_file: byte_file; var f_indx: integer; n:integer);
  {discard n bytes from |f_file|}
  var k:integer;
      x:bite;
  begin
    if n < 0 then abort('Skip_bytes called with negative number');
    f_indx := f_indx + n;
    for k:=1 to n do
    begin
      if eof(f_file) then
      warn('End of file' )
      else read(f_file, x );
    end ;
  end;
    @.Error: End of file@> @.Fatal: Skip_bytes...@>
@z