Utilities

Chapter 17
Utilities

   17.1 Output Character
   17.2 Output String
   17.3 Read Character
   17.4 Read Strings
   17.5 Read Unsigned Integer
   17.6 Read Signed Integer
   17.7 Strings Equality
   17.8 Warnings and Errors
      Messages
      Warnings Commands
      Error Commands
      Extra Characters in Special
      Trace Errors
      Trace Specials
   17.9 Dos
   17.10 Op Codes of Dvi

17.1 Output Character

<..header functions ..>+
static INTEGER insert_ch( ARG_I(int) );
-_-_-

<..functions ..>+

static  INTEGER insert_ch(ch)    int ch
;{
    if( !ignore_chs ){
         BOOL flag;
      <.flag = empty next-str?.>
      if( !flag ){
         try_new_line();
         <.insert ch to text .>
         text_on = TRUE;
    } }
    <.return char width .>
}
-_-_-

/* if (ch � 0) ch+=256; /*NEW */

<..flag = empty next-str?..>
flag = FALSE;
if( <.next-str .> ) {
   if( eq_str(next_str, "") ) {
     flag = TRUE;
     free((void *) next_str);
     next_str = (char *) 0;
} }
-_-_-

<..header functions ..>+
static void put_char( ARG_I(int) );
-_-_-

<..functions ..>+

static void put_char( ch )   int ch
;{
   if(    !ignore_chs
       && !( ((ch==’ ’) || (ch==’\n’)) && no_root_file )
  ){
      <.open output file .>
      if( ch_map_flag ){
         if( special_on || ((ch != ’\n’) && (ch != ’ ’)) ){
             <.insert ch to ch-map .> }
      }else {
         if ( ch == ’\n’ ){ <.insert eoln ch .> }
         else if ( ch == ’ ’ ){ <.insert space ch .> }
         else { (IGNORED) put_4ht_ch( ch, cur_o_file ); }
} }  }
-_-_-

<..vars ..>+
static BOOL special_on = FALSE;
-_-_-

17.2 Output String

<..header functions ..>+
static void print_f( ARG_I(const char*) );
-_-_-

<..functions ..>+

static void print_f(str)    const char* str
;{
   <.open output file .>
   if( ch_map_flag ){
      while( *str ){ put_char( *str );  str++; }
   }else {
     (IGNORED) print_f_4ht( str );
} }
-_-_-

<..header functions ..>+
static void print_f_4ht( ARG_I(const char*) );
-_-_-

<..functions ..>+

static void print_f_4ht(str)    const char* str
;{
   <.open output file .>
   if( ch_map_flag ){
      while( *str ){ put_char( *str );  str++; }
   } else {
      while( *str ){
         (IGNORED) put_4ht_ch( *str, cur_o_file );
         str++;
} } }
-_-_-

17.3 Read Character

<..header functions ..>+
static int get_char( ARG_I(void) );
-_-_-

<..functions ..>+
static int get_char(MYVOID)
{
return (int) getc(dvi_file);
}
-_-_-

<..header functions ..>+
static int get_noop( ARG_I(void) );
-_-_-

<..functions ..>+
static int get_noop(MYVOID)
{      int ch;
   while(  (ch = get_char())  ==  <.no op .> ){;}
   return ch;
}
-_-_-

17.4 Read Strings

<..header functions ..>+
static char* get_str( ARG_I(int) );
-_-_-

<..functions ..>+

static char* get_str(n)      int n
;{                 U_CHAR *q, *p;
    p = q = m_alloc(char,n+1);
    while( n-- ) *q++ = get_char();
    *q = ’\0’;
    return p;
}
-_-_-

17.5 Read Unsigned Integer

<..defines ..>+
#define get_unt(n) fget_unt(dvi_file,n)
-_-_-

<..header functions ..>+
static long fget_unt( ARG_II(FILE*, int) );
-_-_-

<..functions ..>+

static long fget_unt( file, n )
     FILE*     file;
     register int  n

;{  register long val = 0;
   while( n-- ){ val = (val << 8) + (unsigned INTEGER) getc(file) ;  }
   return val;
}
-_-_-

17.6 Read Signed Integer

<..defines ..>+
#define get_int(n) fget_int(dvi_file,n)
-_-_-

<..header functions ..>+
static long fget_int( ARG_II(FILE *, int) );
-_-_-

<..functions ..>+

static long fget_int( file, n )
     FILE *file;
     int   n

;{  register long val;
   val = (unsigned INTEGER) getc(file);
   if( val & 0x80 )     val -= 0x100;
   while( --n ){ val = (val << 8) + (unsigned INTEGER) getc(file); }
   return val;
}
-_-_-

The implementation in dvi2ps takes the following form with the comment “This code assumes that the right-shift is an arithmetic, rather than logical, shift which will propagate the sign bit right. According to Kernighan and Ritchie, this is compiler dependent!”.

val = getc(fp);
n1 = n--;
while (n--) { val <<= 8;
val |= getc(fp); }
val<<=32-8*n1;
val>>=32-8*n1; /* sign extend */

<..header functions ..>+
static long cond_int( ARG_I(register INTEGER) );
-_-_-

<..functions ..>+

static long cond_int( n )
     register INTEGER  n
;{  register long val;
     int  ch;
   val = (unsigned int) (ch = get_char());
   cond_idv_char( ch );
   if( val & 0x80 )     val -= 0x100;
   while( --n ){
     val = (val << 8) + (unsigned int) (ch = get_char());
     cond_idv_char( ch );
   }
   return val;
}
-_-_-

17.7 Strings Equality

<..defines ..>+
#define eq_str(x,y) (!strcmp(x,y))
#define gt_str(x,y) (strcmp(x,y)>0)
-_-_-

17.8 Warnings and Errors

Messages

<..warn and err messages ..>
<.command line options .>,                            0
"Can’t find/open file ‘%s’\n",                       1
"Can’t open output file for ‘%s’\n",                 2
"Can’t close file ‘%s’ (file is not open)\n",        3
"Insufficient memory\n",                              4
"Bad character code: %d\n",                           5
"Can’t find font number %d\n",                        6
"Improper dvi file\n",                                7
"Improper op while scanning font defs in postamble\n",8
"Problem with command line\n",                        9
"Font definition repeated in postamble\n",            10
"Empty entry in font environment variable\n",         11
"Can’t access directory ‘%s\n’",                     12
"Too many directories in font environment variable\n",13
"Missing fonts, can’t proceed\n",                     14
"Invalid header in file ‘%s’\n",                     15
"Checksum inconsistent\n",                            16
"MAXFONTS too small: %d\n",                           17
"Improper signature at end of file ‘%s.htf’\n",      18
"Improper signature at start of file ‘%s.htf’\n",    19
"Improper file ‘%s.htf’\n",                          20
"Couldn’t find font ‘%s.htf’ (char codes: ",        21
"File ‘%s.htf’ starts/ends with character code %d (instead of %d)\n",22
"Implementation problem\n",                           23
"Improper groups in \\special{t4ht+}... idv[%d]\n",   24
"Too many characters (> %d) for map line: ‘%c’\n",   25
"Extra characters in \\special{t4ht%c...",            26
"Page break within a ch map/picture\n",               27
"Char code >255 in htf file: %d\n",                   28
"Improper char for code in htf file: %c\n",           29
<.signals messages: 30-32 .>                           30-32
#ifdef DOS_WIN32
"%c-script too long in tex4ht.env \n",                33
#else
"%c-script too long in tex4ht.env (.tex4ht)\n",       33
#endif
"Too many rows (> %d) for map: ‘%c’\n",              34
"More than 256 strings in font\n",                    35
"\\special{t4ht;%c...}?\n",                           36
"\\special{t4ht;|%s}?\n",                             37
"\\special{t4ht~!%s}?\n",                             38
"\\special{t4ht\"...%s}?\n",                          39
"System error 40\n",                                  40
"‘%c’ in \\special{t4ht@...} or \\special{t4ht@-...}?\n",   41
"\\special{t4ht~...} without \\special{t4ht~}\n",     42
"Ignoring \\special{t4ht.%s}\n",                      43
"PUSH for \\special{t4ht<...%s}?\n",                  44
"Bad character code (%d) in \\special{t4h~}...\n",    45
"Page break in \\special{t4h~}...\n",                 46
"tex4ht.fls: Couldn’t find file ‘%s’\n",             47
"Improper entry (line %d)\n",                         48
"Improper environment variable %s: ‘%s’\n",           49
"Missing %s\n",                                       50
"Can’t back from file ‘%s\n’",                        51
"\\special{t4ht%s}?\n",                               52
"Improper -v option\n",                               53
-_-_-

<..vars ..>+
static const U_CHAR *warn_err_mssg[]={ <.warn and err messages .> "" };
-_-_-

Warnings Commands

<..header functions ..>+
static void warn_i( ARG_I(int) );
-_-_-

<..functions ..>+

static  void warn_i(n)     int  n
;{  (IGNORED) fprintf(stderr,"--- warning --- ");
    (IGNORED) fprintf(stderr, "%s", warn_err_mssg[n]);
    show_err_context();
}
-_-_-

<..warning(22 ..>
(IGNORED) fprintf(stderr,"--- warning --- ");
(IGNORED) fprintf(stderr, warn_err_mssg[22]
-_-_-

<..header functions ..>+
static void warn_i_int( ARG_II(int,int) );
-_-_-

<..functions ..>+

static void warn_i_int(n,i)   int  n; int i

;{  (IGNORED) fprintf(stderr,"--- warning --- ");
    (IGNORED) fprintf(stderr, warn_err_mssg[n], i);
    show_err_context();
}
-_-_-

<..header functions ..>+
static void warn_i_int_2( ARG_III(int,int,int) );
-_-_-

<..functions ..>+

static void warn_i_int_2(n,i,j)   int  n; int i; int j

;{  (IGNORED) fprintf(stderr,"--- warning --- ");
    (IGNORED) fprintf(stderr, warn_err_mssg[n], i, j);
    show_err_context();
}
-_-_-

<..header functions ..>+
static void warn_i_str( ARG_II(int,const char *) );
-_-_-

<..functions ..>+

static void warn_i_str(n,str)
     int  n;
     const char *str

;{
    (IGNORED) fprintf(stderr,"--- warning --- ");
    (IGNORED) fprintf(stderr,warn_err_mssg[n], str);
    show_err_context();
}
-_-_-

<..header functions ..>+
static void warn_i_str2( ARG_III(int,const char *,const char *) );
-_-_-

<..functions ..>+

static void warn_i_str2(n,str1,str2)
     int  n;
     const char *str1;
     const char *str2

;{  (IGNORED) fprintf(stderr,"--- warning --- ");
    (IGNORED) fprintf(stderr,warn_err_mssg[n], str1,str2);
    show_err_context();
}
-_-_-

Error Commands

<..defines ..>+
#define bad_arg            err_i(0)
#define bad_in_file(name)   err_i_str(1,name)
#define bad_out_file(name)  err_i_str(2,name)
#define bad_special(name)   warn_i_str(3,name)
#define bad_mem             err_i(4)
#define bad_char(chr)       warn_i_int(5,chr)
#define bad_dvi             err_i(7)
-_-_-

<..header functions ..>+
static void err_i( ARG_I(int) );
-_-_-

<..functions ..>+

static void err_i(n)      int  n

;{  (IGNORED) fprintf(stderr,"--- error --- ");
    (IGNORED) fprintf(stderr, "%s", warn_err_mssg[n]);
    show_err_context();
    exit(EXIT_FAILURE);
}
-_-_-

REPLACE EXIT with somthing that DOS also accept.

<..header functions ..>+
static void err_i_int( ARG_II(int,int) );
-_-_-

<..functions ..>+

static void err_i_int(n,i)     int  n;  int i

;{  (IGNORED) fprintf(stderr,"--- error --- ");
    (IGNORED) fprintf(stderr, warn_err_mssg[n], i);
    show_err_context();
    exit(EXIT_FAILURE);
}
-_-_-

<..header functions ..>+
static void err_i_str( ARG_II(int,char *) );
-_-_-

<..functions ..>+

static void err_i_str(n,str)
      int  n;
      U_CHAR *str

;{  (IGNORED) fprintf(stderr,"--- error --- ");
    (IGNORED) fprintf(stderr, warn_err_mssg[n], str);
    show_err_context();
    exit(EXIT_FAILURE);
}
-_-_-

Extra Characters in Special

<..check for extra special chars ..>
if( special_n > 0 ){
warn_i_int( 26, sv);
while( special_n-- ) (IGNORED) putc( get_char(), stderr);
}
-_-_-

<..special resolution err ..>
warn_i_int( 26, ’!’);
(IGNORED) putc( ch, stderr);
while( special_n-- ) (IGNORED) putc( get_char(), stderr);
-_-_-

<..consume unused specials ..>
while( special_n-- ) (void) get_char();
-_-_-

<..unused special ..>
;
-_-_-

<..header functions ..>+
static void show_err_context( ARG_I(void) );
-_-_-

<..functions ..>+
static void show_err_context(MYVOID)
{                             long  curr_pos;
                               int n, i;
                               U_CHAR ch;
    if( err_context ){
      curr_pos = ftell(dvi_file);
      for(n=6; n--;){
         (IGNORED) putc( ’\n’, stderr );
         for(i=70; i--;){
           ch = get_char();
           (IGNORED) putc(( (ch>31) && (ch<127))? ch : ’ ’, stderr);
         }
      }
      (IGNORED) fseek(dvi_file, curr_pos, <.abs file addr .>);
      (IGNORED) putc( ’\n’, stderr ); (IGNORED) putc( ’\n’, stderr );
      if( err_mark ){  print_f( err_mark ); }
}  }
-_-_-

A static informs that the function is defined just locally, preventing possible errors when the linker detects name conflicts with definitions that use the same names in other libraries.

<..static ..>
static
-_-_-

<..vars ..>+
static BOOL err_context = FALSE;
-_-_-

<..context for warn and errs ..>
err_context = TRUE;
-_-_-

Trace Errors

<..vars ..>+
static U_CHAR *err_mark = (char *) 0;
-_-_-

<..get err str ..>
if( err_mark ){ free((void *) err_mark); }
if( special_n ){
err_mark = get_str( (int) special_n ); special_n=0;
} else { err_mark = (char *) 0; }
-_-_-

Trace Specials

<..trace specials in dvi ..>
trace_special = TRUE;
-_-_-

<..vars ..>+
static BOOL trace_special = FALSE;
-_-_-

On off with \special{t4ht@/}

<..on/off special trace ..>
trace_special = !trace_special;
-_-_-

<..trace specials ..>
{                             long  curr_pos;
                               int n, i;
                               U_CHAR ch;

    curr_pos = ftell(dvi_file);
    print_f("\nSPECIAL:  ");  ch = special_hd[8]; i=60;
    for( n=*special_n - 3; n--;){
       if( !i ){ (IGNORED) putc( ’\n’, cur_o_file );   i=70; }
       else i--;
       (IGNORED) putc(( (ch>31) && (ch<127))? ch : ’ ’, cur_o_file);
       ch = get_char();
    }
    (IGNORED) putc( ’\n’, cur_o_file );
    (IGNORED) fseek(dvi_file, curr_pos, <.abs file addr .>);
}
-_-_-

17.9 Dos

open(file, ..._FLAGS): All text files should be opened with ”r” or ”w”; all binary files with ”rb” or ”wb”. This is the portable way and will work both under Unix and DOS; as Unix doesn’t distinguish between text and binary files, its compilers will simply ignore the ”b” part.
Unix doesn’t differentiate between binary binary and text files.
In general, the rule of thumb is that DOS/Windows ports should recognize both back- and forward-slashes in their input (such as command-line arguments), but can construct file names by using forward slashes alone (since DOS/Windows kernels support both styles).
On the subject of the .lg file: you open the tex4ht.env file in binary mode (”rb”), which results in strange line endings in the .lg file (CR/CR/LF). Changing the mode to ”r” fixes this.
(WRITE_BIN_FLAGS, READ_BIN_FLAGS): Use binary mode with DJGPP. —captured with the __MSDOS__.

<..defines ..>+
#if defined(DOS_WIN32) || defined(__MSDOS__)
#define READ_BIN_FLAGS "rb"
#define READ_TEXT_FLAGS "r"
#define WRITE_BIN_FLAGS "wb"
#ifdef WIN32
#define WRITE_TEXT_FLAGS "wb"
#else
#define WRITE_TEXT_FLAGS "w"
#endif
#else
#define READ_BIN_FLAGS "r"
#define READ_TEXT_FLAGS "r"
#define WRITE_BIN_FLAGS "w"
#define WRITE_TEXT_FLAGS "w"
#endif
-_-_-
I’ve been held up a bit by a
bug in tex4ht.c that caused emTeX to complain that the created .idv file
was corrupt:

*** Fatal error 2106: corrupt DVI file (postamble not found)

I found the cause, though: you open it with mode "w", which is text
mode. Changing this to "wb" solved the problem.
Argument types in declaration of functions
Function prototypes

<..tex4ht.h ..>+
#ifdef DOS
#define PROTOTYP
#endif
#ifdef ANSI
#define PROTOTYP
#endif
#ifdef KWIN32
#define PROTOTYP
#endif
-_-_-
<..defines ..>+
#ifdef PROTOTYP
#define MYVOID void
#define ARG_I(x) x
#define ARG_II(x,y) x,y
#define ARG_III(x,y,z) x,y,z
#define ARG_IV(x,y,z,w) x,y,z,w
#define ARG_V(x,y,z,w,v) x,y,z,w,v
#define ARG_VI(x,y,z,w,v,u) x,y,z,w,v,u
#define ARG_VII(x,y,z,w,v,u,t) x,y,z,w,v,u,t
#else
#define MYVOID
#define ARG_I(x)
#define ARG_II(x,y)
#define ARG_III(x,y,z)
#define ARG_IV(x,y,z,w)
#define ARG_V(x,y,z,w,v)
#define ARG_VI(x,y,z,w,v,u)
#define ARG_VII(x,y,z,w,v,u,t)
#endif
-_-_-