/* texmfmp.c: Hand-coded routines for TeX or Metafont in C.  Originally
   written by Tim Morgan, drawing from other Unix ports of TeX.  This is
   a collection of miscellany, everything that's easier (or only
   possible) to do in C.
   
   This file is public domain.  */

/* This file is included from, e.g., texextra,c after
      #define EXTERN
      #include <texd.h>
   to instantiate data from texd.h here.  The ?d.h file is what
   #defines TeX or MF, which avoids the need for a special
   Makefile rule.  */

#include <kpathsea/c-ctype.h>
#include <kpathsea/line.h>
#include <kpathsea/readable.h>
#include <kpathsea/variable.h>
#include <kpathsea/absolute.h>
#include <kpathsea/recorder.h>
#ifdef WIN32
#include <kpathsea/concatn.h>
#endif

#include <time.h> /* For `struct tm'.  */
#if defined (HAVE_SYS_TIME_H)
#include <sys/time.h>
#elif defined (HAVE_SYS_TIMEB_H)
#include <sys/timeb.h>
#endif

#if defined(__STDC__)
#include <locale.h>
#endif

#include <signal.h> /* Catch interrupts.  */

#include <texmfmp-help.h>

/* {tex,mf}d.h defines TeX, MF, INI, and other such symbols.
   Unfortunately there's no way to get the banner into this code, so
   just repeat the text.  */
#ifdef TeX
#if defined(XeTeX)
#include <xetexdir/xetexextra.h>
#elif defined (eTeX)
#include <etexdir/etexextra.h>
#elif defined (pdfTeX)
#include <pdftexdir/pdftexextra.h>
#include <pdftexdir/ptexlib.h>
#elif defined (Aleph)
#include <alephdir/alephextra.h>
#elif defined (pTeX)
#include <ptexdir/ptexextra.h>
#elif defined (epTeX)
#include <eptexdir/eptexextra.h>
#else
#define BANNER "This is TeX, Version 3.1415926"
#define COPYRIGHT_HOLDER "D.E. Knuth"
#define AUTHOR NULL
#define PROGRAM_HELP TEXHELP
#define BUG_ADDRESS "tex-k@tug.org"
#define DUMP_VAR TEXformatdefault
#define DUMP_LENGTH_VAR formatdefaultlength
#define DUMP_OPTION "fmt"
#define DUMP_EXT ".fmt"
#define INPUT_FORMAT kpse_tex_format
#define INI_PROGRAM "initex"
#define VIR_PROGRAM "virtex"
#endif
#define edit_var "TEXEDIT"
#endif /* TeX */
#ifdef MF
#define BANNER "This is Metafont, Version 2.718281"
#define COPYRIGHT_HOLDER "D.E. Knuth"
#define AUTHOR NULL
#define PROGRAM_HELP MFHELP
#define BUG_ADDRESS "tex-k@tug.org"
#define DUMP_VAR MFbasedefault
#define DUMP_LENGTH_VAR basedefaultlength
#define DUMP_OPTION "base"
#ifdef DOS
#define DUMP_EXT ".bas"
#else
#define DUMP_EXT ".base"
#endif
#define INPUT_FORMAT kpse_mf_format
#define INI_PROGRAM "inimf"
#define VIR_PROGRAM "virmf"
#define edit_var "MFEDIT"
#endif /* MF */

/* Shell escape.

   If shellenabledp == 0, all shell escapes are forbidden.
   If (shellenabledp == 1 && restrictedshell == 0), any command
     is allowed for a shell escape.
   If (shellenabledp == 1 && restrictedshell == 1), only commands
     given in the configuration file as
   shell_escape_commands = kpsewhich,ebb,extractbb,mpost,metafun,...
     (no spaces between commands) in texmf.cnf are allowed for a shell
     escape in a restricted form: command name and arguments should be
     separated by a white space. The first word should be a command
     name. The quotation character for an argument with spaces,
     including a pathname, should be ".  ' should not be used.

     Internally, all arguments are quoted by ' (Unix) or " (Windows)
     before calling the system() function in order to forbid execution
     of any embedded command.  In addition, on Windows, special
     characters of cmd.exe are escaped by using (^).

   If the --shell-escape option is given, we set
     shellenabledp = 1 and restrictedshell = 0, i.e., any command is allowed.
   If the --shell-restricted option is given, we set
     shellenabledp = 1 and restrictedshell = 1, i.e., only given cmds allowed.
   If the --no-shell-escape option is given, we set
     shellenabledp = -1 (and restrictedshell is irrelevant).
   If none of these option are given, there are three cases:
   (1) In the case where
       shell_escape = y or
       shell_escape = t or
       shell_escape = 1
       it becomes shellenabledp = 1 and restrictedshell = 0,
       that is, any command is allowed.
   (2) In the case where
       shell_escape = p
       it becomes shellenabledp = 1 and restrictedshell = 1,
       that is, restricted shell escape is allowed.
   (3) In all other cases, shellenabledp = 0, that is, shell
       escape is forbidden. The value of restrictedshell is
       irrelevant if shellenabledp == 0.
*/

#ifdef TeX

/* cmdlist is a list of allowed commands which are given like this:
   shell_escape_commands = kpsewhich,ebb,extractbb,mpost,metafun
   in texmf.cnf. */

static char **cmdlist = NULL;

void 
mk_shellcmdlist (const char *v)
{
  char **p;
  const char *q, *r1;
  char *r;
  int  n;

  q = v;
  n = 0;

/* analyze the variable shell_escape_commands = foo,bar,...
   spaces before and after (,) are not allowed. */

  while ((r1 = strchr (q, ',')) != 0) {
    n++;
    r1++;
    q = r1;
  }
  if (*q)
    n++;
  cmdlist = xmalloc ((n + 1) * sizeof (char *));
  p = cmdlist;
  q = v;
  while ((r = strchr (q, ',')) != 0) {
    *r = '\0';
    *p = xmalloc (strlen (q) + 1);
    strcpy (*p, q);
    *r = ',';
    r++;
    q = r;
    p++;
  }
  if (*q) {
    *p = xmalloc (strlen (q) + 1);
    strcpy (*p, q);
    p++;
    *p = NULL;
  } else
    *p = NULL;
}

/* Called from maininit.  Not static because also called from
   luatexdir/lua/luainit.c.  */

void
init_shell_escape (void)
{
  if (shellenabledp < 0) {  /* --no-shell-escape on cmd line */
    shellenabledp = 0;

  } else {
    if (shellenabledp == 0) {  /* no shell options on cmd line, check cnf */
      char *v1 = kpse_var_value ("shell_escape");
      if (v1) {
        if (*v1 == 't' || *v1 == 'y' || *v1 == '1') {
          shellenabledp = 1;
        } else if (*v1 == 'p') {
          shellenabledp = 1;
          restrictedshell = 1;
        }
        free (v1);
      }
    }

    /* If shell escapes are restricted, get allowed cmds from cnf.  */   
    if (shellenabledp && restrictedshell == 1) {
      char *v2 = kpse_var_value ("shell_escape_commands");
      if (v2) {
        mk_shellcmdlist ((const char *)v2);
        free (v2);
      }
    }
  }
}

#ifdef WIN32
#define QUOTE '"'
#else
#define QUOTE '\''
#endif

#ifdef WIN32
static int
char_needs_quote (int c)
{
/* special characters of cmd.exe */

  return (c == '&' || c == '|' || c == '%' || c == '<' ||
          c == '>' || c == ';' || c == ',' || c == '(' ||
          c == ')');
}
#endif

static int
Isspace (char c)
{
  return (c == ' ' || c == '\t');
}

#if 0
/* We could call this at the end of the main program, but does it matter?
   The process is about to exit anyway.  */
static void
free_shellcmdlist (void)
{
  char **p;

  if (cmdlist) {
    p = cmdlist;
    while (*p) {
      free (*p);
      p++;
    }
    free (cmdlist);
  }
}
#endif

/* return values:
  -1 : invalid quotation of an argument
   0 : command is not allowed
   2 : restricted shell escape, CMD is allowed.
   
   We set *SAFECMD to a safely-quoted version of *CMD; this is what
   should get executed.  And we set CMDNAME to its first word; this is
   what is checked against the shell_escape_commands list.  */

int
shell_cmd_is_allowed (const char *cmd, char **safecmd, char **cmdname)
{
  char **p;
  char *buf;
  char *c, *d;
  const char *s;
  int  pre, spaces;
  int  allow = 0;

  /* pre == 1 means that the previous character is a white space
     pre == 0 means that the previous character is not a white space */
  buf = xmalloc (strlen (cmd) + 1);
  strcpy (buf, cmd);
  c = buf;
  while (Isspace (*c))
    c++;
  d = c;
  while (!Isspace(*d) && *d)
    d++;
  *d = '\0';

  /* *cmdname is the first word of the command line.  For example,
     *cmdname == "kpsewhich" for
     \write18{kpsewhich --progname=dvipdfm --format="other text files" config}
  */
  *cmdname = xstrdup (c);
  free (buf);

  /* Is *cmdname listed in a texmf.cnf vriable as
     shell_escape_commands = foo,bar,... ? */
  p = cmdlist;
  if (p) {
    while (*p) {
      if (strcmp (*p, *cmdname) == 0) {
      /* *cmdname is found in the list, so restricted shell escape
          is allowed */
        allow = 2;
        break;
      }
      p++;
    }
  }
  if (allow == 2) {
    spaces = 0;
    for (s = cmd; *s; s++) {
      if (Isspace (*s))
        spaces++;
    }

    /* allocate enough memory (too much?) */
#ifdef WIN32
    *safecmd = xmalloc (2 * strlen (cmd) + 3 + 2 * spaces);
#else
    *safecmd = xmalloc (strlen (cmd) + 3 + 2 * spaces);
#endif

    /* make a safe command line *safecmd */
    s = cmd;
    while (Isspace (*s))
      s++;
    d = *safecmd;
    while (!Isspace (*s) && *s)
      *d++ = *s++;

    pre = 1;
    while (*s) {
      /* Quotation given by a user.  " should always be used; we
         transform it below.  If ' is used, simply immediately
         return a quotation error.  */
      if (*s == '\'') {
        return -1;
      }
         
      if (*s == '"') {
        /* All arguments are quoted as 'foo' (Unix) or "foo" (Windows)
           before calling system(). Therefore closing QUOTE is necessary
           if the previous character is not a white space.
           example:
           --format="other text files" becomes
           '--format=''other text files' (Unix)
           "--format=""other text files" (Windows) */

        if (pre == 0)
          *d++ = QUOTE;

        pre = 0;
        /* output the quotation mark for the quoted argument */
        *d++ = QUOTE;
        s++;

        while (*s != '"') {
          /* Illegal use of ', or closing quotation mark is missing */
          if (*s == '\'' || *s == '\0')
            return -1;
#ifdef WIN32
          if (char_needs_quote (*s))
            *d++ = '^';
#endif
          *d++ = *s++;
        }

        /* Closing quotation mark will be output afterwards, so
           we do nothing here */
        s++;

        /* The character after the closing quotation mark
           should be a white space or NULL */
        if (!Isspace (*s) && *s)
          return -1;

      /* Beginning of a usual argument */
      } else if (pre == 1 && !Isspace (*s)) {
        pre = 0;
        *d++ = QUOTE;
#ifdef WIN32
        if (char_needs_quote (*s))
          *d++ = '^';
#endif
        *d++ = *s++;
        /* Ending of a usual argument */

      } else if (pre == 0 && Isspace (*s)) {
        pre = 1;
        /* Closing quotation mark */
        *d++ = QUOTE;
        *d++ = *s++;
      } else {
        /* Copy a character from cmd to *safecmd. */
#ifdef WIN32
        if (char_needs_quote (*s))
          *d++ = '^';
#endif
        *d++ = *s++;
      }
    }
    /* End of the command line */
    if (pre == 0) {
      *d++ = QUOTE;
    }
    *d = '\0';
#ifdef WIN32
    {
      char *p, *q, *r;
      p = *safecmd;
      if (!(IS_DIR_SEP (p[0]) && IS_DIR_SEP (p[1])) &&
          !(p[1] == ':' && IS_DIR_SEP (p[2]))) { 
        p = (char *) kpse_var_value ("SELFAUTOLOC");
        if (p) {
          r = *safecmd;
          while (*r && !Isspace(*r))
            r++;
          if (*r == '\0')
            q = concatn ("\"", p, "/", *safecmd, "\"", NULL);
          else {
            *r = '\0';
            r++;
            while (*r && Isspace(*r))
              r++;
            if (*r)
              q = concatn ("\"", p, "/", *safecmd, "\" ", r, NULL);
            else
              q = concatn ("\"", p, "/", *safecmd, "\"", NULL);
          }
          free (p);
          free (*safecmd);
          *safecmd = q;
        }
      }
    }
#endif
  }

  return allow;
}

/* We should only be called with shellenabledp == 1.
   Return value:
   -1 if a quotation syntax error.
   0 if CMD is not allowed; given shellenabledp==1, this is because
      shell escapes are restricted and CMD is not allowed.
   1 if shell escapes are not restricted, hence any command is allowed.
   2 if shell escapes are restricted and CMD is allowed (possibly after
      quoting).  */
   
int
runsystem (const char *cmd)
{
  int allow = 0;
  char *safecmd = NULL;
  char *cmdname = NULL;

  if (shellenabledp <= 0) {
    return 0;
  }
  
  /* If restrictedshell == 0, any command is allowed. */
  if (restrictedshell == 0)
    allow = 1;
  else
    allow = shell_cmd_is_allowed (cmd, &safecmd, &cmdname);

  if (allow == 1)
    (void) system (cmd);
  else if (allow == 2)
    (void) system (safecmd);

  if (safecmd)
    free (safecmd);
  if (cmdname)
    free (cmdname);

  return allow;
}

#ifdef pdfTeX
/* Like runsystem(), the runpopen() function is called only when
   shellenabledp == 1.   Unlike runsystem(), here we write errors to
   stderr, since we have nowhere better to use; and of course we return
   a file handle (or NULL) instead of a status indicator.  */

static FILE *
runpopen (const char *cmd, const char *mode)
{
  FILE *f = NULL;
  char *safecmd = NULL;
  char *cmdname = NULL;
  int allow;

  /* If restrictedshell == 0, any command is allowed. */
  if (restrictedshell == 0)
    allow = 1;
  else
    allow = shell_cmd_is_allowed (cmd, &safecmd, &cmdname);

  if (allow == 1)
    f = popen (cmd, mode);
  else if (allow == 2)
    f = popen (safecmd, mode);
  else if (allow == -1)
    fprintf (stderr, "\nrunpopen quotation error in command line: %s\n",
             cmd);
  else
    fprintf (stderr, "\nrunpopen command not allowed: %s\n", cmdname);

  if (safecmd)
    free (safecmd);
  if (cmdname)
    free (cmdname);
  return f;
}
#endif /* pdfTeX */
#endif /* TeX */

/* The main program, etc.  */

#ifdef XeTeX
#include "xetexdir/XeTeX_ext.h"
#endif

/* What we were invoked as and with.  */
char **argv;
int argc;

/* If the user overrides argv[0] with -progname.  */
static const_string user_progname;

/* The C version of what might wind up in DUMP_VAR.  */
static const_string dump_name;

/* The C version of the jobname, if given. */
static const_string c_job_name;

/* The filename for dynamic character translation, or NULL.  */
string translate_filename;
string default_translate_filename;

#if defined(TeX)
/* Needed for --src-specials option. */
static char *last_source_name;
static int last_lineno;
static boolean srcspecialsoption = false;
static void parse_src_specials_option (const_string);
#endif

/* Parsing a first %&-line in the input file. */
static void parse_first_line (const_string);

/* Parse option flags. */
static void parse_options (int, string *);

/* Try to figure out if we have been given a filename. */
static string get_input_file_name (void);

#if defined(Aleph)
/* Declare this for Omega family, so they can parse the -8bit option,
 * even though it is a no-op for them.
 */
static int eightbitp;
#endif /* Aleph */

/* Get a true/false value for a variable from texmf.cnf and the environment. */
static boolean
texmf_yesno(const_string var)
{
  string value = kpse_var_value (var);
  return value && (*value == 't' || *value == 'y' || *value == '1');
}

#ifdef pdfTeX
const char *ptexbanner = BANNER;
#endif

/* The entry point: set up for reading the command line, which will
   happen in `topenin', then call the main body.  */

void
maininit (int ac, string *av)
{
  string main_input_file;

  /* Save to pass along to topenin.  */
  argc = ac;
  argv = av;

  /* Must be initialized before options are parsed.  */
  interactionoption = 4;
#if defined(pTeX) || defined(epTeX)
  set_enc_string (NULL, "default");
#endif /* pTeX || epTeX */

  /* Have things to record as we go along.  */
  kpse_record_input = recorder_record_input;
  kpse_record_output = recorder_record_output;

#if defined(__SyncTeX__)
# warning SyncTeX: -synctex command line option available
  /* 0 means "disable Synchronize TeXnology".
     synctexoption is a *.web variable.
     We initialize it to a weird value to catch the -synctex command line flag.
     At runtime, if synctexoption is not INT_MAX, then it contains the
     command line option provided; otherwise, no such option was given
     by the user.  */
# define SYNCTEX_NO_OPTION INT_MAX
  synctexoption = SYNCTEX_NO_OPTION;
#else
# /* Omit warning for Aleph, pTeX, epTeX, and non-TeX.  */
# if defined(TeX) && !defined(Aleph) && !defined(pTeX) && !defined(epTeX)
#  warning SyncTeX: -synctex command line option NOT available
# endif
#endif

  /* If the user says --help or --version, we need to notice early.  And
     since we want the --ini option, have to do it before getting into
     the web (which would read the base file, etc.).  */
  parse_options (ac, av);
  
  /* If -progname was not specified, default to the dump name.  */
  if (!user_progname)
    user_progname = dump_name;
  
  /* Do this early so we can inspect kpse_invocation_name and
     kpse_program_name below, and because we have to do this before
     any path searching.  */
  kpse_set_program_name (argv[0], user_progname);

  /* FIXME: gather engine names in a single spot. */
  xputenv ("engine", TEXMFENGINENAME);
  
  /* Were we given a simple filename? */
  main_input_file = get_input_file_name();

  /* Second chance to activate file:line:error style messages, this
     time from texmf.cnf. */
  if (filelineerrorstylep < 0) {
    filelineerrorstylep = 0;
  } else if (!filelineerrorstylep) {
    filelineerrorstylep = texmf_yesno ("file_line_error_style");
  }

  /* If no dump default yet, and we're not doing anything special on
     this run, we may want to look at the first line of the main input
     file for a %&<dumpname> specifier.  */
  if (parsefirstlinep < 0) {
    parsefirstlinep = 0;
  } else if (!parsefirstlinep) {
    parsefirstlinep = texmf_yesno ("parse_first_line");
  }
  if (parsefirstlinep && (!dump_name || !translate_filename)) {
    parse_first_line (main_input_file);
  }
  /* Check whether there still is no translate_filename known.  If so,
     use the default_translate_filename. */
  /* FIXME: deprecated. */
  if (!translate_filename) {
    translate_filename = default_translate_filename;
  }
  /* If we're preloaded, I guess everything is set up.  I don't really
     know any more, it's been so long since anyone preloaded.  */
  if (readyalready != 314159) {
    /* The `ini_version' variable is declared/used in the change files.  */
    boolean virversion = false;
    if (FILESTRCASEEQ (kpse_program_name, INI_PROGRAM)) {
      iniversion = true;
    } else if (FILESTRCASEEQ (kpse_program_name, VIR_PROGRAM)) {
      virversion = true;
#ifdef TeX
    } else if (FILESTRCASEEQ (kpse_program_name, "initex")) {
      iniversion = true;
    } else if (FILESTRCASEEQ (kpse_program_name, "virtex")) {
      virversion = true;
#ifndef Aleph
    } else if (FILESTRCASEEQ (kpse_program_name, "mltex")) {
      mltexp = true;
#endif /* !Aleph */
#endif /* TeX */
    }

    if (!dump_name) {
      /* If called as *vir{mf,tex,mpost} use `plain'.  Otherwise, use the
         name we were invoked under.  */
      dump_name = (virversion ? "plain" : kpse_program_name);
    }
  }
  
#ifdef TeX
  /* Sanity check: -mltex, -enc, -etex only work in combination with -ini. */
  if (!iniversion) {
#if !defined(Aleph)
    if (mltexp) {
      fprintf(stderr, "-mltex only works with -ini\n");
    }
#if !defined(XeTeX) && !defined(pTeX) && !defined(epTeX)
    if (enctexp) {
      fprintf(stderr, "-enc only works with -ini\n");
    }
#endif
#endif
#if defined(eTeX) || defined(epTeX) || defined(Aleph) || defined(XeTeX)
    if (etexp) {
      fprintf(stderr, "-etex only works with -ini\n");
    }
#endif
  }
#endif
  
  /* If we've set up the fmt/base default in any of the various ways
     above, also set its length.  */
  if (dump_name) {
    const_string with_ext = NULL;
    unsigned name_len = strlen (dump_name);
    unsigned ext_len = strlen (DUMP_EXT);
    
    /* Provide extension if not there already.  */
    if (name_len > ext_len
        && FILESTRCASEEQ (dump_name + name_len - ext_len, DUMP_EXT)) {
      with_ext = dump_name;
    } else {
      with_ext = concat (dump_name, DUMP_EXT);
    }
    DUMP_VAR = concat (" ", with_ext); /* adjust array for Pascal */
    DUMP_LENGTH_VAR = strlen (DUMP_VAR + 1);
  } else {
    /* For dump_name to be NULL is a bug.  */
    abort();
  }

  /* Additional initializations.  No particular reason for doing them
     here instead of first thing in the change file; less symbols to
     propagate through Webc, that's all.  */
#ifdef MF
  kpse_set_program_enabled (kpse_mf_format, MAKE_TEX_MF_BY_DEFAULT,
                            kpse_src_compile);
  kpse_set_program_enabled (kpse_base_format, MAKE_TEX_FMT_BY_DEFAULT,
                            kpse_src_compile);
#endif /* MF */
#ifdef TeX
#if defined (Aleph)
  kpse_set_program_enabled (kpse_ocp_format, MAKE_OMEGA_OCP_BY_DEFAULT,
                            kpse_src_compile);
  kpse_set_program_enabled (kpse_ofm_format, MAKE_OMEGA_OFM_BY_DEFAULT,
                            kpse_src_compile);
  kpse_set_program_enabled (kpse_tfm_format, false, kpse_src_compile);
#else /* !Aleph */
  kpse_set_program_enabled (kpse_tfm_format, MAKE_TEX_TFM_BY_DEFAULT,
                            kpse_src_compile);
#endif /* !Aleph */
  kpse_set_program_enabled (kpse_tex_format, MAKE_TEX_TEX_BY_DEFAULT,
                            kpse_src_compile);
  kpse_set_program_enabled (kpse_fmt_format, MAKE_TEX_FMT_BY_DEFAULT,
                            kpse_src_compile);

  init_shell_escape ();

  if (!outputcomment) {
    outputcomment = kpse_var_value ("output_comment");
  }
#endif /* TeX */
}

#if !defined(WIN32) || defined(__MINGW32__)
/* The entry point: set up for reading the command line, which will
   happen in `topenin', then call the main body.  */

int
main (int ac, string *av)
{
#ifdef __EMX__
  _wildcard (&ac, &av);
  _response (&ac, &av);
#endif

#ifdef WIN32
  _setmaxstdio(2048);
#endif

  maininit (ac, av);

  /* Call the real main program.  */
  mainbody ();
  
  return EXIT_SUCCESS;
} 
#endif /* !WIN32 || __MINGW32__ */


/* This is supposed to ``open the terminal for input'', but what we
   really do is copy command line arguments into TeX's or Metafont's
   buffer, so they can handle them.  If nothing is available, or we've
   been called already (and hence, argc==0), we return with
   `last=first'.  */

void
topenin (void)
{
  int i;

#ifdef XeTeX
  static UFILE termin_file;
  if (termin == 0) {
    termin = &termin_file;
    termin->f = stdin;
    termin->savedChar = -1;
    termin->skipNextLF = 0;
    termin->encodingMode = UTF8;
    termin->conversionData = 0;
    inputfile[0] = termin;
  }
#endif

  buffer[first] = 0; /* In case there are no arguments.  */

  if (optind < argc) { /* We have command line arguments.  */
    int k = first;
    for (i = optind; i < argc; i++) {
#ifdef XeTeX
      unsigned char *ptr = (unsigned char *)&(argv[i][0]);
      /* need to interpret UTF8 from the command line */
      UInt32 rval;
      while ((rval = *(ptr++)) != 0) {
        UInt16 extraBytes = bytesFromUTF8[rval];
        switch (extraBytes) { /* note: code falls through cases! */
          case 5: rval <<= 6; if (*ptr) rval += *(ptr++);
          case 4: rval <<= 6; if (*ptr) rval += *(ptr++);
          case 3: rval <<= 6; if (*ptr) rval += *(ptr++);
          case 2: rval <<= 6; if (*ptr) rval += *(ptr++);
          case 1: rval <<= 6; if (*ptr) rval += *(ptr++);
          case 0: ;
        };
        rval -= offsetsFromUTF8[extraBytes];
        buffer[k++] = rval;
      }
#else
      char *ptr = &(argv[i][0]);
      /* Don't use strcat, since in Aleph the buffer elements aren't
         single bytes.  */
      while (*ptr) {
        buffer[k++] = *(ptr++);
      }
#endif
      buffer[k++] = ' ';
    }
    argc = 0;	/* Don't do this again.  */
    buffer[k] = 0;
  }

  /* Find the end of the buffer.  */
  for (last = first; buffer[last]; ++last)
    ;

  /* Make `last' be one past the last non-blank character in `buffer'.  */
  /* ??? The test for '\r' should not be necessary.  */
  for (--last; last >= first
       && ISBLANK (buffer[last]) && buffer[last] != '\r'; --last) 
    ;
  last++;

  /* One more time, this time converting to TeX's internal character
     representation.  */
#if !defined(Aleph) && !defined(XeTeX)
  for (i = first; i < last; i++)
    buffer[i] = xord[buffer[i]];
#endif
}

/* IPC for TeX.  By Tom Rokicki for the NeXT; it makes TeX ship out the
   DVI file in a pipe to TeXView so that the output can be displayed
   incrementally.  Shamim Mohamed adapted it for Web2c.  */
#if defined (TeX) && defined (IPC)

#ifdef WIN32
#include <winsock2.h>
#else
#include <sys/socket.h>
#include <fcntl.h>
#ifndef O_NONBLOCK /* POSIX */
#ifdef O_NDELAY    /* BSD */
#define O_NONBLOCK O_NDELAY
#else
#ifdef FNDELAY     /* NeXT */
#define O_NONBLOCK O_FNDELAY
#else
what the fcntl? cannot implement IPC without equivalent for O_NONBLOCK.
#endif /* no FNDELAY */
#endif /* no O_NDELAY */
#endif /* no O_NONBLOCK */
#endif /* !WIN32 */

#ifndef IPC_PIPE_NAME /* $HOME is prepended to this.  */
#define IPC_PIPE_NAME "/.TeXview_Pipe"
#endif
#ifndef IPC_SERVER_CMD /* Command to run to start the server.  */
#define IPC_SERVER_CMD "open `which TeXview`"
#endif

struct msg
{
  short namelength; /* length of auxiliary data */
  int eof;   /* new eof for dvi file */
#if 0  /* see usage of struct msg below */
  char more_data[0]; /* where the rest of the stuff goes */ 
#endif
};

static char *ipc_name;
static struct sockaddr *ipc_addr;
static int ipc_addr_len;

static int
ipc_make_name (void)
{
  if (ipc_addr_len == 0) {
    string s = getenv ("HOME");
    if (s) {
      ipc_addr = (struct sockaddr*)xmalloc (strlen (s) + 40);
      ipc_addr->sa_family = 0;
      ipc_name = ipc_addr->sa_data;
      strcpy (ipc_name, s);
      strcat (ipc_name, IPC_PIPE_NAME);
      ipc_addr_len = strlen (ipc_name) + 3;
    }
  }
  return ipc_addr_len;
}


static int sock = -1;

static int
ipc_is_open (void)
{
   return sock >= 0;
}


static void
ipc_open_out (void) {
#ifdef WIN32
  u_long mode = 1;
#define SOCK_NONBLOCK(s) ioctlsocket (s, FIONBIO, &mode)
#else
#define SOCK_NONBLOCK(s) fcntl (s, F_SETFL, O_NONBLOCK)
#endif
#ifdef IPC_DEBUG
  fputs ("tex: Opening socket for IPC output ...\n", stderr);
#endif
  if (sock >= 0) {
    return;
  }

  if (ipc_make_name () < 0) {
    sock = -1;
    return;
  }

  sock = socket (PF_UNIX, SOCK_STREAM, 0);
  if (sock >= 0) {
    if (connect (sock, ipc_addr, ipc_addr_len) != 0
        || SOCK_NONBLOCK (sock) < 0) {
      close (sock);
      sock = -1;
      return;
    }
#ifdef IPC_DEBUG
    fputs ("tex: Successfully opened IPC socket.\n", stderr);
#endif
  }
}


static void
ipc_close_out (void)
{
#ifdef IPC_DEBUG
  fputs ("tex: Closing output socket ...\n", stderr);
#endif
  if (ipc_is_open ()) {
    close (sock);
    sock = -1;
  }
}


static void
ipc_snd (int n, int is_eof, char *data)
{
  struct
  {
    struct msg msg;
    char more_data[1024];
  } ourmsg;

#ifdef IPC_DEBUG
  fputs ("tex: Sending message to socket ...\n", stderr);
#endif
  if (!ipc_is_open ()) {
    return;
  }

  ourmsg.msg.namelength = n;
  ourmsg.msg.eof = is_eof;
  if (n) {
    strcpy (ourmsg.more_data, data);
  }
  n += sizeof (struct msg);
#ifdef IPC_DEBUG
  fputs ("tex: Writing to socket...\n", stderr);
#endif
  if (write (sock, &ourmsg, n) != n) {
    ipc_close_out ();
  }
#ifdef IPC_DEBUG
  fputs ("tex: IPC message sent.\n", stderr);
#endif
}


/* This routine notifies the server if there is an eof, or the filename
   if a new DVI file is starting.  This is the routine called by TeX.
   Aleph defines str_start(#) as str_start_ar[# - too_big_char], with
   too_big_char = biggest_char + 1 = 65536 (omstr.ch).*/

void
ipcpage (int is_eof)
{
  static boolean begun = false;
  unsigned len = 0;
  string p = NULL;

  if (!begun) {
    string name; /* Just the filename.  */
    string cwd = xgetcwd ();
    
    ipc_open_out ();
#if !defined(Aleph)
    len = strstart[outputfilename + 1] - strstart[outputfilename];
#else
    len = strstartar[outputfilename + 1 - 65536L] -
            strstartar[outputfilename - 65536L];
#endif
    name = xmalloc (len + 1);
#if !defined(Aleph)
    strncpy (name, (string)&strpool[strstart[outputfilename]], len);
#else
    {
    unsigned i;
    for (i=0; i<len; i++)
      name[i] =  strpool[i+strstartar[outputfilename - 65536L]];
    }
#endif
    name[len] = 0;
    
    /* Have to pass whole filename to the other end, since it may have
       been started up and running as a daemon, e.g., as with the NeXT
       preview program.  */
    p = concat3 (cwd, DIR_SEP_STRING, name);
    free (name);
    len = strlen(p);
    begun = true;
  }
  ipc_snd (len, is_eof, p);
  
  if (p) {
    free (p);
  }
}
#endif /* TeX && IPC */

#if defined (TeX) || defined (MF)
  /* TCX and Aleph&Co get along like sparks and gunpowder. */
#if !defined(Aleph) && !defined(XeTeX)

/* Return the next number following START, setting POST to the following
   character, as in strtol.  Issue a warning and return -1 if no number
   can be parsed.  */

static int
tcx_get_num (int upb,
             unsigned line_count,
             string start,
             string *post)
{
  int num = strtol (start, post, 0);
  assert (post && *post);
  if (*post == start) {
    /* Could not get a number. If blank line, fine. Else complain.  */
    string p = start;
    while (*p && ISSPACE (*p))
      p++;
    if (*p != 0)
      fprintf (stderr, "%s:%d: Expected numeric constant, not `%s'.\n",
               translate_filename, line_count, start);
    num = -1;
  } else if (num < 0 || num > upb) {
    fprintf (stderr, "%s:%d: Destination charcode %d <0 or >%d.\n",
             translate_filename, line_count, num, upb);
    num = -1;
  }  

  return num;
}

/* Update the xchr, xord, and xprn arrays for TeX, allowing a
   translation table specified at runtime via an external file.
   Look for the character translation file FNAME along the same path as
   tex.pool.  If no suffix in FNAME, use .tcx (don't bother trying to
   support extension-less names for these files).  */

/* FIXME: A new format ought to be introduced for these files. */

void
readtcxfile (void)
{
  string orig_filename;
  if (!find_suffix (translate_filename)) {
    translate_filename = concat (translate_filename, ".tcx");
  }
  orig_filename = translate_filename;
  translate_filename
    = kpse_find_file (translate_filename, kpse_web2c_format, true);
  if (translate_filename) {
    string line;
    unsigned line_count = 0;
    FILE *translate_file = xfopen (translate_filename, FOPEN_R_MODE);
    while ((line = read_line (translate_file))) {
      int first;
      string start2;
      string comment_loc = strchr (line, '%');
      if (comment_loc)
        *comment_loc = 0;

      line_count++;

      first = tcx_get_num (255, line_count, line, &start2);
      if (first >= 0) {
        string start3;
        int second;
        int printable;
        
        second = tcx_get_num (255, line_count, start2, &start3);
        if (second >= 0) {
            /* I suppose we could check for nonempty junk following the
               "printable" code, but let's not bother.  */
          string extra;
            
          /* If they mention a second code, make that the internal number.  */
          xord[first] = second;
          xchr[second] = first;

          printable = tcx_get_num (1, line_count, start3, &extra);
          /* Not-a-number, may be a comment. */
          if (printable == -1)
            printable = 1;
          /* Don't allow the 7bit ASCII set to become unprintable. */
          if (32 <= second && second <= 126)
            printable = 1;
        } else {
          second = first; /* else make internal the same as external */
          /* If they mention a charcode, call it printable.  */
          printable = 1;
        }

        xprn[second] = printable;
      }
      free (line);
    }
    xfclose(translate_file, translate_filename);
  } else {
    WARNING1 ("Could not open char translation file `%s'", orig_filename);
  }
}
#endif /* !Aleph && !XeTeX */
#endif /* TeX || MF [character translation] */

#ifdef XeTeX /* XeTeX handles this differently, and allows odd quotes within names */
string
normalize_quotes (const_string name, const_string mesg)
{
    int quote_char = 0;
    boolean must_quote = false;
    int len = strlen(name);
    /* Leave room for quotes and NUL. */
    string ret;
    string p;
    const_string q;
    for (q = name; *q; q++) {
        if (*q == ' ') {
            if (!must_quote) {
                len += 2;
                must_quote = true;
            }
        }
        else if (*q == '\"' || *q == '\'') {
            must_quote = true;
            if (quote_char == 0)
                quote_char = '\"' + '\'' - *q;
            len += 2; /* this could sometimes add length we don't need */
        }
    }
    ret = xmalloc(len + 1);
    p = ret;
    if (must_quote) {
        if (quote_char == 0)
            quote_char = '\"';
        *p++ = quote_char;
    }
    for (q = name; *q; q++) {
        if (*q == quote_char) {
            *p++ = quote_char;
            quote_char = '\"' + '\'' - quote_char;
            *p++ = quote_char;
        }
        *p++ = *q;
    }
    if (quote_char != 0)
        *p++ = quote_char;
    *p = '\0';
    return ret;
}
#else
/* Normalize quoting of filename -- that is, only quote if there is a space,
   and always use the quote-name-quote style. */
string
normalize_quotes (const_string name, const_string mesg)
{
    boolean quoted = false;
    boolean must_quote = (strchr(name, ' ') != NULL);
    /* Leave room for quotes and NUL. */
    string ret = xmalloc(strlen(name)+3);
    string p;
    const_string q;
    p = ret;
    if (must_quote)
        *p++ = '"';
    for (q = name; *q; q++) {
        if (*q == '"')
            quoted = !quoted;
        else
            *p++ = *q;
    }
    if (must_quote)
        *p++ = '"';
    *p = '\0';
    if (quoted) {
        fprintf(stderr, "! Unbalanced quotes in %s %s\n", mesg, name);
        uexit(1);
    }
    return ret;
}
#endif

/* Getting the input filename. */
string
get_input_file_name (void)
{
  string input_file_name = NULL;

  if (argv[optind] && argv[optind][0] != '&' && argv[optind][0] != '\\') {
    /* Not &format, not \input, so assume simple filename. */    
#ifdef XeTeX
    string name = normalize_quotes(argv[optind], "argument");
    input_file_name = kpse_find_file(argv[optind], INPUT_FORMAT, false);
    argv[optind] = name;
#else
    string name = normalize_quotes(argv[optind], "argument");
    boolean quoted = (name[0] == '"');
    if (quoted) {
        /* Overwrite last quote and skip first quote. */
        name[strlen(name)-1] = '\0';
        name++;
    }
    input_file_name = kpse_find_file(name, INPUT_FORMAT, false);
    if (quoted) {
        /* Undo modifications */
        name[strlen(name)] = '"';
        name--;
    }
    argv[optind] = name;
#endif
  }
  return input_file_name;
}

/* Reading the options.  */

/* Test whether getopt found an option ``A''.
   Assumes the option index is in the variable `option_index', and the
   option table in a variable `long_options'.  */
#define ARGUMENT_IS(a) STREQ (long_options[option_index].name, a)

/* SunOS cc can't initialize automatic structs, so make this static.  */
static struct option long_options[]
  = { { DUMP_OPTION,                 1, 0, 0 },
#ifdef TeX
      /* FIXME: Obsolete -- for backward compatibility only. */
      { "efmt",                      1, 0, 0 },
#endif
      { "help",                      0, 0, 0 },
      { "ini",                       0, &iniversion, 1 },
      { "interaction",               1, 0, 0 },
      { "halt-on-error",             0, &haltonerrorp, 1 },
      { "kpathsea-debug",            1, 0, 0 },
      { "progname",                  1, 0, 0 },
      { "version",                   0, 0, 0 },
      { "recorder",                  0, &recorder_enabled, 1 },
#ifdef TeX
#ifdef IPC
      { "ipc",                       0, &ipcon, 1 },
      { "ipc-start",                 0, &ipcon, 2 },
#endif /* IPC */
#if !defined(Aleph)
      { "mltex",                     0, &mltexp, 1 },
#if !defined(XeTeX) && !defined(pTeX) && !defined(epTeX)
      { "enc",                       0, &enctexp, 1 },
#endif /* !XeTeX && !pTeX && !epTeX */
#endif /* !Aleph */
#if defined (eTeX) || defined (epTeX) || defined(pdfTeX) || defined(Aleph) || defined(XeTeX)
      { "etex",                      0, &etexp, 1 },
#endif /* eTeX || epTeX || pdfTeX || Aleph */
      { "output-comment",            1, 0, 0 },
#if defined(pdfTeX)
      { "draftmode",                 0, 0, 0 },
      { "output-format",             1, 0, 0 },
#endif /* pdfTeX */
      { "shell-escape",              0, &shellenabledp, 1 },
      { "no-shell-escape",           0, &shellenabledp, -1 },
      { "enable-write18",            0, &shellenabledp, 1 },
      { "disable-write18",           0, &shellenabledp, -1 },
      { "shell-restricted",          0, 0, 0 },
      { "debug-format",              0, &debugformatfile, 1 },
      { "src-specials",              2, 0, 0 },
#if defined(__SyncTeX__)
      /* Synchronization: just like "interaction" above */
      { "synctex",                   1, 0, 0 },
#endif
#endif /* TeX */
#if defined (TeX) || defined (MF)
      { "file-line-error-style",     0, &filelineerrorstylep, 1 },
      { "no-file-line-error-style",  0, &filelineerrorstylep, -1 },
      /* Shorter option names for the above. */
      { "file-line-error",           0, &filelineerrorstylep, 1 },
      { "no-file-line-error",        0, &filelineerrorstylep, -1 },
      { "jobname",                   1, 0, 0 },
      { "output-directory",          1, 0, 0 },
      { "parse-first-line",          0, &parsefirstlinep, 1 },
      { "no-parse-first-line",       0, &parsefirstlinep, -1 },
      { "translate-file",            1, 0, 0 },
      { "default-translate-file",    1, 0, 0 },
      { "8bit",                      0, &eightbitp, 1 },
#if defined(XeTeX)
      { "no-pdf",                 0, &nopdfoutput, 1 },
      { "output-driver",          1, 0, 0 },
      { "papersize",              1, 0, 0 },
#endif /* XeTeX */
      { "mktex",                     1, 0, 0 },
      { "no-mktex",                  1, 0, 0 },
#endif /* TeX or MF */
#if defined(pTeX) || defined(epTeX)
      { "kanji",                     1, 0, 0 },
#endif /* pTeX || epTeX */
      { 0, 0, 0, 0 } };


static void
parse_options (int argc, string *argv)
{
  int g;   /* `getopt' return code.  */
  int option_index;

  for (;;) {
    g = getopt_long_only (argc, argv, "+", long_options, &option_index);

    if (g == -1) /* End of arguments, exit the loop.  */
      break;

    if (g == '?') { /* Unknown option.  */
      /* FIXME: usage (argv[0]); replaced by continue. */
      continue;
    }

    assert (g == 0); /* We have no short option names.  */

    if (ARGUMENT_IS ("kpathsea-debug")) {
      kpathsea_debug |= atoi (optarg);

#ifdef XeTeX
    } else if (ARGUMENT_IS ("papersize")) {
      papersize = optarg;
    } else if (ARGUMENT_IS ("output-driver")) {
      outputdriver = optarg;
#endif

    } else if (ARGUMENT_IS ("progname")) {
      user_progname = optarg;

    } else if (ARGUMENT_IS ("jobname")) {
#ifdef XeTeX
      c_job_name = optarg;
#else
      c_job_name = normalize_quotes (optarg, "jobname");
#endif

    } else if (ARGUMENT_IS (DUMP_OPTION)) {
      dump_name = optarg;
      dumpoption = true;

#ifdef TeX
    /* FIXME: Obsolete -- for backward compatibility only. */
    } else if (ARGUMENT_IS ("efmt")) {
      dump_name = optarg;
      dumpoption = true;
#endif

    } else if (ARGUMENT_IS ("output-directory")) {
      output_directory = optarg;
      
#ifdef TeX
    } else if (ARGUMENT_IS ("output-comment")) {
      unsigned len = strlen (optarg);
      if (len < 256) {
        outputcomment = optarg;
      } else {
        WARNING2 ("Comment truncated to 255 characters from %d. (%s)",
                  len, optarg);
        outputcomment = xmalloc (256);
        strncpy (outputcomment, optarg, 255);
        outputcomment[255] = 0;
      }

#ifdef IPC
    } else if (ARGUMENT_IS ("ipc-start")) {
      ipc_open_out ();
      /* Try to start up the other end if it's not already.  */
      if (!ipc_is_open ()) {
        if (system (IPC_SERVER_CMD) == 0) {
          unsigned i;
          for (i = 0; i < 20 && !ipc_is_open (); i++) {
#ifdef WIN32
            Sleep (2000);
#else
            sleep (2);
#endif
            ipc_open_out ();
          }
        }
      }
#endif /* IPC */

    } else if (ARGUMENT_IS ("shell-restricted")) {
      shellenabledp = 1;
      restrictedshell = 1;
      
    } else if (ARGUMENT_IS ("src-specials")) {
       last_source_name = xstrdup("");
       /* Option `--src" without any value means `auto' mode. */
       if (optarg == NULL) {
         insertsrcspecialeverypar = true;
         insertsrcspecialauto = true;
         srcspecialsoption = true;
         srcspecialsp = true;
       } else {
          parse_src_specials_option(optarg);
       }
#endif /* TeX */
#if defined(pdfTeX)
    } else if (ARGUMENT_IS ("output-format")) {
       pdfoutputoption = 1;
       if (strcmp(optarg, "dvi") == 0) {
         pdfoutputvalue = 0;
       } else if (strcmp(optarg, "pdf") == 0) {
         pdfoutputvalue = 2;
       } else {
         WARNING1 ("Ignoring unknown value `%s' for --output-format", optarg);
         pdfoutputoption = 0;
       }
    } else if (ARGUMENT_IS ("draftmode")) {
      pdfdraftmodeoption = 1;
      pdfdraftmodevalue = 1;
#endif /* pdfTeX */
#if defined (TeX) || defined (MF)
    } else if (ARGUMENT_IS ("translate-file")) {
      translate_filename = optarg;
    } else if (ARGUMENT_IS ("default-translate-file")) {
      default_translate_filename = optarg;
#if defined(Aleph)
    } else if (ARGUMENT_IS ("8bit")) {
      /* FIXME: print snippy message? Possibly also for above? */
#endif /* !Aleph */
    } else if (ARGUMENT_IS ("mktex")) {
      kpse_maketex_option (optarg, true);

    } else if (ARGUMENT_IS ("no-mktex")) {
      kpse_maketex_option (optarg, false);
#endif /* TeX or MF */
    } else if (ARGUMENT_IS ("interaction")) {
        /* These numbers match @d's in *.ch */
      if (STREQ (optarg, "batchmode")) {
        interactionoption = 0;
      } else if (STREQ (optarg, "nonstopmode")) {
        interactionoption = 1;
      } else if (STREQ (optarg, "scrollmode")) {
        interactionoption = 2;
      } else if (STREQ (optarg, "errorstopmode")) {
        interactionoption = 3;
      } else {
        WARNING1 ("Ignoring unknown argument `%s' to --interaction", optarg);
      }
#if defined(pTeX) || defined(epTeX)
    } else if (ARGUMENT_IS ("kanji")) {
      if (!set_enc_string (optarg, NULL)) {
        WARNING1 ("Ignoring unknown argument `%s' to --kanji", optarg);
      }
#endif /* pTeX || epTeX */

    } else if (ARGUMENT_IS ("help")) {
        usagehelp (PROGRAM_HELP, BUG_ADDRESS);

#if defined(__SyncTeX__)
    } else if (ARGUMENT_IS ("synctex")) {
		/* Synchronize TeXnology: catching the command line option as a long  */
		synctexoption = (int) strtol(optarg, NULL, 0);
#endif

    } else if (ARGUMENT_IS ("version")) {
        char *versions;
#if defined (pdfTeX) || defined(XeTeX)
        initversionstring(&versions); 
#else
        versions = NULL;
#endif
        printversionandexit (BANNER, COPYRIGHT_HOLDER, AUTHOR, versions);

    } /* Else it was a flag; getopt has already done the assignment.  */
  }
}

#if defined(TeX)
void 
parse_src_specials_option (const_string opt_list)
{
  char * toklist = xstrdup(opt_list);
  char * tok;
  insertsrcspecialauto = false;
  tok = strtok (toklist, ", ");
  while (tok) {
    if (strcmp (tok, "everypar") == 0
        || strcmp (tok, "par") == 0
        || strcmp (tok, "auto") == 0) {
      insertsrcspecialauto = true;
      insertsrcspecialeverypar = true;
    } else if (strcmp (tok, "everyparend") == 0
               || strcmp (tok, "parend") == 0)
      insertsrcspecialeveryparend = true;
    else if (strcmp (tok, "everycr") == 0
             || strcmp (tok, "cr") == 0)
      insertsrcspecialeverycr = true;
    else if (strcmp (tok, "everymath") == 0
             || strcmp (tok, "math") == 0)
      insertsrcspecialeverymath = true;
    else if (strcmp (tok, "everyhbox") == 0
             || strcmp (tok, "hbox") == 0)
      insertsrcspecialeveryhbox = true;
    else if (strcmp (tok, "everyvbox") == 0
             || strcmp (tok, "vbox") == 0)
      insertsrcspecialeveryvbox = true;
    else if (strcmp (tok, "everydisplay") == 0
             || strcmp (tok, "display") == 0)
      insertsrcspecialeverydisplay = true;
    else if (strcmp (tok, "none") == 0) {
      /* This one allows to reset an option that could appear in texmf.cnf */
      insertsrcspecialauto = insertsrcspecialeverypar = 
        insertsrcspecialeveryparend = insertsrcspecialeverycr = 
        insertsrcspecialeverymath =  insertsrcspecialeveryhbox =
        insertsrcspecialeveryvbox = insertsrcspecialeverydisplay = false;
    } else {
      WARNING1 ("Ignoring unknown argument `%s' to --src-specials", tok);
    }
    tok = strtok(0, ", ");
  }
  free(toklist);
  srcspecialsp=insertsrcspecialauto | insertsrcspecialeverypar |
    insertsrcspecialeveryparend | insertsrcspecialeverycr |
    insertsrcspecialeverymath |  insertsrcspecialeveryhbox |
    insertsrcspecialeveryvbox | insertsrcspecialeverydisplay;
  srcspecialsoption = true;
}
#endif

/* If the first thing on the command line (we use the globals `argv' and
   `optind') is a normal filename (i.e., does not start with `&' or
   `\'), and if we can open it, and if its first line is %&FORMAT, and
   FORMAT is a readable dump file, then set DUMP_VAR to FORMAT.
   Also call kpse_reset_program_name to ensure the correct paths for the
   format are used.  */
static void
parse_first_line (const_string filename)
{
  FILE *f = filename ? fopen (filename, FOPEN_R_MODE) : NULL;
  if (f) {
    string first_line = read_line (f);
    xfclose (f, filename);

    /* We deal with the general format "%&fmt --translate-file=tcx" */
    /* The idea of using this format came from Wlodzimierz Bzyl
       <matwb@monika.univ.gda.pl> */
    if (first_line && first_line[0] == '%' && first_line[1] == '&') {
      /* Parse the first line into at most three space-separated parts. */
      char *s;
      char *part[4];
      int npart;
      char **parse;

      for (s = first_line+2; ISBLANK(*s); ++s)
        ;
      npart = 0;
      while (*s && npart != 3) {
        part[npart++] = s;
        while (*s && *s != ' ') s++;
        while (*s == ' ') *s++ = '\0';
      }
      part[npart] = NULL;
      parse = part;
      /* Look at what we've got.  Very crude! */
      if (*parse && **parse != '-') {
        /* A format name */
        if (dump_name) {
          /* format already determined, do nothing. */
        } else {
          string f_name = concat (part[0], DUMP_EXT);
          string d_name = kpse_find_file (f_name, DUMP_FORMAT, false);
          if (d_name && kpse_readable_file (d_name)) {
            dump_name = xstrdup (part[0]);
            kpse_reset_program_name (dump_name);
            /* Tell TeX/MF/MP we have a %&name line... */
            dumpline = true;
          }
          free (f_name);
        }
        parse++;
      }
      /* The tcx stuff, if any.  Should we support the -translate-file
         form as well as --translate-file?  */
      if (*parse) {
        s = NULL;
        if (translate_filename) {
          /* TCX file already set, do nothing. */
        } else if (STREQ (*parse, "--translate-file")) {
          s = *(parse+1);
        } else if (STREQ (*parse, "-translate-file")) {
          s = *(parse+1);
        } else if (STRNEQ (*parse, "--translate-file=", 17)) {
          s = *parse+17;
        } else if (STRNEQ (*parse, "-translate-file=", 16)) {
          s = *parse+16;
        }
        /* Just set the name, no sanity checks here. */
        /* FIXME: remove trailing spaces. */
        if (s && *s) {
          translate_filename = xstrdup(s);
        }
      }
    }
    if (first_line)
      free (first_line);
  }
}

/* 
  piped I/O
 */

/* The code that implements popen() needs an array for tracking 
   possible pipe file pointers, because these need to be
   closed using pclose().
*/

#if defined(pdfTeX)

static FILE *pipes [] = {NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,
                         NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL};

boolean
open_in_or_pipe (FILE **f_ptr, int filefmt, const_string fopen_mode)
{
    string fname = NULL;
    int i; /* iterator */
    
    /* opening a read pipe is straightforward, only have to
       skip past the pipe symbol in the file name. filename
       quoting is assumed to happen elsewhere (it does :-)) */

    if (shellenabledp && *(nameoffile+1) == '|') {
      /* the user requested a pipe */
      *f_ptr = NULL;
      fname = xmalloc(strlen((const_string)(nameoffile+1))+1);
      strcpy(fname,(const_string)(nameoffile+1));
      recorder_record_input (fname + 1);
      *f_ptr = runpopen(fname+1,"r");
      free(fname);
      for (i=0; i<=15; i++) {
        if (pipes[i]==NULL) {
          pipes[i] = *f_ptr;
          break;
        }
      }
      if (*f_ptr)
        setvbuf (*f_ptr,NULL,_IOLBF,0);

      return *f_ptr != NULL;
    }

    return open_input(f_ptr,filefmt,fopen_mode) ;
}


boolean
open_out_or_pipe (FILE **f_ptr, const_string fopen_mode)
{
    string fname;
    int i; /* iterator */

    /* opening a write pipe takes a little bit more work, because TeX
       will perhaps have appended ".tex".  To avoid user confusion as
       much as possible, this extension is stripped only when the command
       is a bare word.  Some small string trickery is needed to make
       sure the correct number of bytes is free()-d afterwards */
	
    if (shellenabledp && *(nameoffile+1) == '|') {
      /* the user requested a pipe */
      fname = xmalloc(strlen((const_string)(nameoffile+1))+1);
      strcpy(fname,(const_string)(nameoffile+1));
      if (strchr (fname,' ')==NULL && strchr(fname,'>')==NULL) {
        /* mp and mf currently do not use this code, but it 
           is better to be prepared */
        if (STREQ((fname+strlen(fname)-3),"tex"))
          *(fname+strlen(fname)-4) = 0;
        *f_ptr = runpopen(fname+1,"w");
        *(fname+strlen(fname)) = '.';
      } else {
        *f_ptr = runpopen(fname+1,"w");
      }
      recorder_record_output (fname + 1);
      free(fname);

      for (i=0; i<=15; i++) {
        if (pipes[i]==NULL) {
          pipes[i] = *f_ptr;
          break;
        }
      }

      if (*f_ptr)
        setvbuf(*f_ptr,NULL,_IOLBF,0);

      return *f_ptr != NULL;
    }

    return open_output(f_ptr,fopen_mode);
}


void
close_file_or_pipe (FILE *f)
{
  int i; /* iterator */

  if (shellenabledp) {
    /* if this file was a pipe, pclose() it and return */    
    for (i=0; i<=15; i++) {
      if (pipes[i] == f) {
        if (f)
          pclose (f);
        pipes[i] = NULL;
        return;
      }
    }
  }
  close_file(f);
}
#endif

/* All our interrupt handler has to do is set TeX's or Metafont's global
   variable `interrupt'; then they will do everything needed.  */
#ifdef WIN32
/* Win32 doesn't set SIGINT ... */
static BOOL WINAPI
catch_interrupt (DWORD arg)
{
  switch (arg) {
  case CTRL_C_EVENT:
  case CTRL_BREAK_EVENT:
    interrupt = 1;
    return TRUE;
  default:
    /* No need to set interrupt as we are exiting anyway */
    return FALSE;
  }
}
#else /* not WIN32 */
static RETSIGTYPE
catch_interrupt (int arg)
{
  interrupt = 1;
#ifdef OS2
  (void) signal (SIGINT, SIG_ACK);
#else
  (void) signal (SIGINT, catch_interrupt);
#endif /* not OS2 */
}
#endif /* not WIN32 */

/* Besides getting the date and time here, we also set up the interrupt
   handler, for no particularly good reason.  It's just that since the
   `fix_date_and_time' routine is called early on (section 1337 in TeX,
   ``Get the first line of input and prepare to start''), this is as
   good a place as any.  */

void
get_date_and_time (integer *minutes,  integer *day,
                   integer *month,  integer *year)
{
  time_t myclock = time ((time_t *) 0);
  struct tm *tmptr = localtime (&myclock);

  *minutes = tmptr->tm_hour * 60 + tmptr->tm_min;
  *day = tmptr->tm_mday;
  *month = tmptr->tm_mon + 1;
  *year = tmptr->tm_year + 1900;

  {
#ifdef SA_INTERRUPT
    /* Under SunOS 4.1.x, the default action after return from the
       signal handler is to restart the I/O if nothing has been
       transferred.  The effect on TeX is that interrupts are ignored if
       we are waiting for input.  The following tells the system to
       return EINTR from read() in this case.  From ken@cs.toronto.edu.  */

    struct sigaction a, oa;

    a.sa_handler = catch_interrupt;
    sigemptyset (&a.sa_mask);
    sigaddset (&a.sa_mask, SIGINT);
    a.sa_flags = SA_INTERRUPT;
    sigaction (SIGINT, &a, &oa);
    if (oa.sa_handler != SIG_DFL)
      sigaction (SIGINT, &oa, (struct sigaction *) 0);
#else /* no SA_INTERRUPT */
#ifdef WIN32
    SetConsoleCtrlHandler(catch_interrupt, TRUE);
#else /* not WIN32 */
    RETSIGTYPE (*old_handler) (int);
    
    old_handler = signal (SIGINT, catch_interrupt);
    if (old_handler != SIG_DFL)
      signal (SIGINT, old_handler);
#endif /* not WIN32 */
#endif /* no SA_INTERRUPT */
  }
}

/*
 Getting a high resolution time.
 */
void
get_seconds_and_micros (integer *seconds,  integer *micros)
{
#if defined (HAVE_GETTIMEOFDAY)
  struct timeval tv;
  gettimeofday(&tv, NULL);
  *seconds = tv.tv_sec;
  *micros  = tv.tv_usec;
#elif defined (HAVE_FTIME)
  struct timeb tb;
  ftime(&tb);
  *seconds = tb.time;
  *micros  = tb.millitm*1000;
#else
  time_t myclock = time((time_t*)NULL);
  *seconds = myclock;
  *micros  = 0;
#endif
}

/*
  Generating a better seed numbers
  */
integer
getrandomseed(void)
{
#if defined (HAVE_GETTIMEOFDAY)
  struct timeval tv;
  gettimeofday(&tv, NULL);
  return (tv.tv_usec + 1000000 * tv.tv_usec);
#elif defined (HAVE_FTIME)
  struct timeb tb;
  ftime(&tb);
  return (tb.millitm + 1000 * tb.time);
#else
  time_t myclock = time ((time_t*)NULL);
  struct tm *tmptr = localtime(&myclock);
  return (tmptr->tm_sec + 60*(tmptr->tm_min + 60*tmptr->tm_hour));
#endif
}

/* Read a line of input as efficiently as possible while still looking
   like Pascal.  We set `last' to `first' and return `false' if we get
   to eof.  Otherwise, we return `true' and set last = first +
   length(line except trailing whitespace).  */

#ifndef XeTeX /* for XeTeX, we have a replacement function in XeTeX_ext.c */
boolean
input_line (FILE *f)
{
  int i = EOF;

  /* Recognize either LF or CR as a line terminator.  */
#if defined(pTeX) || defined(epTeX)
  last = input_line2(f, buffer, first, bufsize, &i);
#else /* pTeX || epTeX */
  last = first;
  while (last < bufsize && (i = getc (f)) != EOF && i != '\n' && i != '\r')
    buffer[last++] = i;
#endif /* pTeX || epTeX */

  if (i == EOF && errno != EINTR && last == first)
    return false;

  /* We didn't get the whole line because our buffer was too small.  */
  if (i != EOF && i != '\n' && i != '\r') {
    fprintf (stderr, "! Unable to read an entire line---bufsize=%u.\n",
                     (unsigned) bufsize);
    fputs ("Please increase buf_size in texmf.cnf.\n", stderr);
    uexit (1);
  }

  buffer[last] = ' ';
  if (last >= maxbufstack)
    maxbufstack = last;

  /* If next char is LF of a CRLF, read it.  */
  if (i == '\r') {
    while ((i = getc (f)) == EOF && errno == EINTR)
      ;
    if (i != '\n')
      ungetc (i, f);
  }
  
  /* Trim trailing whitespace.  */
  while (last > first && ISBLANK (buffer[last - 1]))
    --last;

  /* Don't bother using xord if we don't need to.  */
#if !defined(Aleph)
  for (i = first; i <= last; i++)
     buffer[i] = xord[buffer[i]];
#endif

#if defined(pTeX) || defined(epTeX)
  for (i = last+1; (i < last + 5 && i < bufsize) ; i++)
    buffer[i] = '\0';
#endif /* pTeX || epTeX */

    return true;
}
#endif /* !XeTeX */

/* This string specifies what the `e' option does in response to an
   error message.  */ 
static const_string edit_value = EDITOR;

/* This procedure originally due to sjc@s1-c.  TeX & Metafont call it when
   the user types `e' in response to an error, invoking a text editor on
   the erroneous source file.  FNSTART is how far into FILENAME the
   actual filename starts; FNLENGTH is how long the filename is.  */
   
void
calledit (packedASCIIcode *filename,
          poolpointer fnstart,
          integer fnlength,
          integer linenumber)
{
  char *temp, *command;
  char c;
  int sdone, ddone, i;

  sdone = ddone = 0;
  filename += fnstart;

  /* Close any open input files, since we're going to kill the job.  */
  for (i = 1; i <= inopen; i++)
#ifdef XeTeX
    xfclose (inputfile[i]->f, "inputfile");
#else
    xfclose (inputfile[i], "inputfile");
#endif

  /* Replace the default with the value of the appropriate environment
     variable or config file value, if it's set.  */
  temp = kpse_var_value (edit_var);
  if (temp != NULL)
    edit_value = temp;

  /* Construct the command string.  The `11' is the maximum length an
     integer might be.  */
  command = xmalloc (strlen (edit_value) + fnlength + 11);

  /* So we can construct it as we go.  */
  temp = command;

  while ((c = *edit_value++) != 0)
    {
      if (c == '%')
        {
          switch (c = *edit_value++)
            {
	    case 'd':
	      if (ddone)
                FATAL ("call_edit: `%%d' appears twice in editor command");
              sprintf (temp, "%ld", (long int)linenumber);
              while (*temp != '\0')
                temp++;
              ddone = 1;
              break;

	    case 's':
              if (sdone)
                FATAL ("call_edit: `%%s' appears twice in editor command");
              for (i =0; i < fnlength; i++)
		*temp++ = Xchr (filename[i]);
              sdone = 1;
              break;

	    case '\0':
              *temp++ = '%';
              /* Back up to the null to force termination.  */
	      edit_value--;
	      break;

	    default:
	      *temp++ = '%';
	      *temp++ = c;
	      break;
	    }
	}
      else
	*temp++ = c;
    }

  *temp = 0;

  /* Execute the command.  */
  if (system (command) != 0)
    fprintf (stderr, "! Trouble executing `%s'.\n", command);

  /* Quit, since we found an error.  */
  uexit (1);
}

/* Read and write dump files.  As distributed, these files are
   architecture dependent; specifically, BigEndian and LittleEndian
   architectures produce different files.  These routines always output
   BigEndian files.  This still does not guarantee them to be
   architecture-independent, because it is possible to make a format
   that dumps a glue ratio, i.e., a floating-point number.  Fortunately,
   none of the standard formats do that.  */

#if !defined (WORDS_BIGENDIAN) && !defined (NO_DUMP_SHARE) /* this fn */

/* This macro is always invoked as a statement.  It assumes a variable
   `temp'.  */
   
#define SWAP(x, y) temp = (x); (x) = (y); (y) = temp


/* Make the NITEMS items pointed at by P, each of size SIZE, be the
   opposite-endianness of whatever they are now.  */

static void
swap_items (char *p, int nitems, int size)
{
  char temp;

  /* Since `size' does not change, we can write a while loop for each
     case, and avoid testing `size' for each time.  */
  switch (size)
    {
    /* 16-byte items happen on the DEC Alpha machine when we are not
       doing sharable memory dumps.  */
    case 16:
      while (nitems--)
        {
          SWAP (p[0], p[15]);
          SWAP (p[1], p[14]);
          SWAP (p[2], p[13]);
          SWAP (p[3], p[12]);
          SWAP (p[4], p[11]);
          SWAP (p[5], p[10]);
          SWAP (p[6], p[9]);
          SWAP (p[7], p[8]);
          p += size;
        }
      break;

    case 8:
      while (nitems--)
        {
          SWAP (p[0], p[7]);
          SWAP (p[1], p[6]);
          SWAP (p[2], p[5]);
          SWAP (p[3], p[4]);
          p += size;
        }
      break;

    case 4:
      while (nitems--)
        {
          SWAP (p[0], p[3]);
          SWAP (p[1], p[2]);
          p += size;
        }
      break;

    case 2:
      while (nitems--)
        {
          SWAP (p[0], p[1]);
          p += size;
        }
      break;

    case 1:
      /* Nothing to do.  */
      break;

    default:
      FATAL1 ("Can't swap a %d-byte item for (un)dumping", size);
  }
}
#endif /* not WORDS_BIGENDIAN and not NO_DUMP_SHARE */


/* Here we write NITEMS items, each item being ITEM_SIZE bytes long.
   The pointer to the stuff to write is P, and we write to the file
   OUT_FILE.  */

void
#ifdef XeTeX
do_dump (char *p, int item_size, int nitems,  gzFile out_file)
#else
do_dump (char *p, int item_size, int nitems,  FILE *out_file)
#endif
{
#if !defined (WORDS_BIGENDIAN) && !defined (NO_DUMP_SHARE)
  swap_items (p, nitems, item_size);
#endif

#ifdef XeTeX
  if (gzwrite (out_file, p, item_size * nitems) != item_size * nitems)
#else
  if (fwrite (p, item_size, nitems, out_file) != nitems)
#endif
    {
      fprintf (stderr, "! Could not write %d %d-byte item(s) to %s.\n",
               nitems, item_size, nameoffile+1);
      uexit (1);
    }

  /* Have to restore the old contents of memory, since some of it might
     get used again.  */
#if !defined (WORDS_BIGENDIAN) && !defined (NO_DUMP_SHARE)
  swap_items (p, nitems, item_size);
#endif
}


/* Here is the dual of the writing routine.  */

void
#ifdef XeTeX
do_undump (char *p, int item_size, int nitems, gzFile in_file)
#else
do_undump (char *p, int item_size, int nitems, FILE *in_file)
#endif
{
#ifdef XeTeX
  if (gzread (in_file, p, item_size * nitems) != item_size * nitems)
#else
  if (fread (p, item_size, nitems, in_file) != (size_t) nitems)
#endif
    FATAL3 ("Could not undump %d %d-byte item(s) from %s",
            nitems, item_size, nameoffile+1);

#if !defined (WORDS_BIGENDIAN) && !defined (NO_DUMP_SHARE)
  swap_items (p, nitems, item_size);
#endif
}

/* FIXME -- some (most?) of this can/should be moved to the Pascal/WEB side. */
#if defined(TeX) || defined(MF)
#if !defined(pdfTeX)
static void
checkpoolpointer (poolpointer poolptr, size_t len)
{
  if (poolptr + len >= poolsize) {
    fprintf (stderr, "\nstring pool overflow [%i bytes]\n", 
            (int)poolsize); /* fixme */
    exit(1);
  }
}

#ifndef XeTeX	/* XeTeX uses this from XeTeX_mac.c */
static
#endif
int
maketexstring(const_string s)
{
  size_t len;
#ifdef XeTeX
  UInt32 rval;
  const unsigned char* cp = (const unsigned char*)s;
#endif
  assert (s != 0);
  len = strlen(s);
  checkpoolpointer (poolptr, len); /* in the XeTeX case, this may be more than enough */
#ifdef XeTeX
  while ((rval = *(cp++)) != 0) {
  UInt16 extraBytes = bytesFromUTF8[rval];
  switch (extraBytes) { /* note: code falls through cases! */
    case 5: rval <<= 6; if (*cp) rval += *(cp++);
    case 4: rval <<= 6; if (*cp) rval += *(cp++);
    case 3: rval <<= 6; if (*cp) rval += *(cp++);
    case 2: rval <<= 6; if (*cp) rval += *(cp++);
    case 1: rval <<= 6; if (*cp) rval += *(cp++);
    case 0: ;
  };
  rval -= offsetsFromUTF8[extraBytes];
  if (rval > 0xffff) {
    rval -= 0x10000;
    strpool[poolptr++] = 0xd800 + rval / 0x0400;
    strpool[poolptr++] = 0xdc00 + rval % 0x0400;
  }
  else
    strpool[poolptr++] = rval;
  }
#else /* ! XeTeX */
  while (len-- > 0)
    strpool[poolptr++] = *s++;
#endif /* ! XeTeX */

  return (makestring());
}
#endif /* !pdfTeX */

strnumber
makefullnamestring(void)
{
  return maketexstring(fullnameoffile);
}

/* Get the job name to be used, which may have been set from the
   command line. */
strnumber
getjobname(strnumber name)
{
    strnumber ret = name;
    if (c_job_name != NULL)
      ret = maketexstring(c_job_name);
    return ret;
}
#endif

#if defined(TeX)
static int
compare_paths (const_string p1, const_string p2)
{
  int ret;
  while (
#ifdef MONOCASE_FILENAMES
                (((ret = (toupper(*p1) - toupper(*p2))) == 0) && (*p2 != 0))
#else
         (((ret = (*p1 - *p2)) == 0) && (*p2 != 0))
#endif
                || (IS_DIR_SEP(*p1) && IS_DIR_SEP(*p2))) {
       p1++, p2++;
  }
  ret = (ret < 0 ? -1 : (ret > 0 ? 1 : 0));
  return ret;
}

#ifdef XeTeX /* the string pool is UTF-16 but we want a UTF-8 string */

string
gettexstring (strnumber s)
{
  unsigned bytesToWrite = 0;
  poolpointer len, i, j;
  string name;
  len = strstart[s + 1 - 65536L] - strstart[s - 65536L];
  name = xmalloc(len * 3 + 1); /* max UTF16->UTF8 expansion
                                  (code units, not bytes) */
  for (i = 0, j = 0; i < len; i++) {
    unsigned c = strpool[i + strstart[s - 65536L]];
    if (c >= 0xD800 && c <= 0xDBFF) {
      unsigned lo = strpool[++i + strstart[s - 65536L]];
      if (lo >= 0xDC00 && lo <= 0xDFFF)
        c = (c - 0xD800) * 0x0400 + lo - 0xDC00;
      else
        c = 0xFFFD;
    }
    if (c < 0x80)
      bytesToWrite = 1;
    else if (c < 0x800)
      bytesToWrite = 2;
    else if (c < 0x10000)
      bytesToWrite = 3;
    else if (c < 0x110000)
      bytesToWrite = 4;
    else {
      bytesToWrite = 3;
      c = 0xFFFD;
    }

    j += bytesToWrite;
    switch (bytesToWrite) { /* note: everything falls through. */
      case 4: name[--j] = ((c | 0x80) & 0xBF); c >>= 6;
      case 3: name[--j] = ((c | 0x80) & 0xBF); c >>= 6;
      case 2: name[--j] = ((c | 0x80) & 0xBF); c >>= 6;
      case 1: name[--j] =  (c | firstByteMark[bytesToWrite]);
    }
    j += bytesToWrite;
  }
  name[j] = 0;
  return name;
}

#else

string
gettexstring (strnumber s)
{
  poolpointer len;
  string name;
#if !defined(Aleph)
  len = strstart[s + 1] - strstart[s];
#else
  len = strstartar[s + 1 - 65536L] - strstartar[s - 65536L];
#endif
  name = (string)xmalloc (len + 1);
#if !defined(Aleph)
  strncpy (name, (string)&strpool[strstart[s]], len);
#else
  {
  poolpointer i;
  /* Don't use strncpy.  The strpool is not made up of chars. */
  for (i=0; i<len; i++) name[i] =  strpool[i+strstartar[s - 65536L]];
  }
#endif
  name[len] = 0;
  return name;
}

#endif /* not XeTeX */

boolean
isnewsource (strnumber srcfilename, int lineno)
{
  char *name = gettexstring(srcfilename);
  return (compare_paths(name, last_source_name) != 0 || lineno != last_lineno);
}

void
remembersourceinfo (strnumber srcfilename, int lineno)
{
  if (last_source_name)
       free(last_source_name);
  last_source_name = gettexstring(srcfilename);
  last_lineno = lineno;
}

poolpointer
makesrcspecial (strnumber srcfilename, int lineno)
{
  poolpointer oldpoolptr = poolptr;
  char *filename = gettexstring(srcfilename);
  /* FIXME: Magic number. */
  char buf[40];
  char * s = buf;

  /* Always put a space after the number, which makes things easier
   * to parse.
   */
  sprintf (buf, "src:%d ", lineno);

  if (poolptr + strlen(buf) + strlen(filename) >= (size_t)poolsize) {
       fprintf (stderr, "\nstring pool overflow\n"); /* fixme */
       exit (1);
  }
  s = buf;
  while (*s)
    strpool[poolptr++] = *s++;

  s = filename;
  while (*s)
    strpool[poolptr++] = *s++;
       
  return (oldpoolptr);
}
#endif

/* Metafont/MetaPost fraction routines. Replaced either by assembler or C.
   The assembler syntax doesn't work on Solaris/x86.  */
#ifndef TeX
#if defined (__sun__) || defined (__cplusplus)
#define NO_MF_ASM
#endif
#if defined(WIN32) && !defined(NO_MF_ASM) && !defined(__MINGW32__)
#include "lib/mfmpw32.c"
#elif defined (__i386__) && defined (__GNUC__) && !defined (NO_MF_ASM)
#include "lib/mfmpi386.asm"
#else
/* Replace fixed-point fraction routines from mf.web and mp.web with
   Hobby's floating-point C code.  */

/****************************************************************
Copyright 1990 - 1995 by AT&T Bell Laboratories.

Permission to use, copy, modify, and distribute this software
and its documentation for any purpose and without fee is hereby
granted, provided that the above copyright notice appear in all
copies and that both that the copyright notice and this
permission notice and warranty disclaimer appear in supporting
documentation, and that the names of AT&T Bell Laboratories or
any of its entities not be used in advertising or publicity
pertaining to distribution of the software without specific,
written prior permission.

AT&T disclaims all warranties with regard to this software,
including all implied warranties of merchantability and fitness.
In no event shall AT&T be liable for any special, indirect or
consequential damages or any damages whatsoever resulting from
loss of use, data or profits, whether in an action of contract,
negligence or other tortious action, arising out of or in
connection with the use or performance of this software.
****************************************************************/

/**********************************************************
 The following is by John Hobby
 **********************************************************/

#ifndef FIXPT

/* These replacements for takefraction, makefraction, takescaled, makescaled
   run about 3 to 11 times faster than the standard versions on modern machines
   that have fast hardware for double-precision floating point.  They should
   produce approximately correct results on all machines and agree exactly
   with the standard versions on machines that satisfy the following conditions:
   1. Doubles must have at least 46 mantissa bits; i.e., numbers expressible
      as n*2^k with abs(n)<2^46 should be representable.
   2. The following should hold for addition, subtraction, and multiplcation but
      not necessarily for division:
      A. If the true answer is between two representable numbers, the computed
         answer must be one of them.
      B. When the true answer is representable, this must be the computed result.
   3. Dividing one double by another should always produce a relative error of
      at most one part in 2^46.  (This is why the mantissa requirement is
      46 bits instead of 45 bits.)
   3. In the absence of overflow, double-to-integer conversion should truncate
      toward zero and do this in an exact fashion.
   4. Integer-to-double convesion should produce exact results.
   5. Dividing one power of two by another should yield an exact result.
   6. ASCII to double conversion should be exact for integer values.
   7. Integer arithmetic must be done in the two's-complement system.
*/
#define ELGORDO  0x7fffffff
#define TWEXP31  2147483648.0
#define TWEXP28  268435456.0
#define TWEXP16 65536.0
#define TWEXP_16 (1.0/65536.0)
#define TWEXP_28 (1.0/268435456.0)

integer
ztakefraction (integer p, integer q)     /* Approximate p*q/2^28 */
{	register double d;
	register integer i;
	d = (double)p * (double)q * TWEXP_28;
	if ((p^q) >= 0) {
		d += 0.5;
		if (d>=TWEXP31) {
			if (d!=TWEXP31 || (((p&077777)*(q&077777))&040000)==0)
				aritherror = true;
			return ELGORDO;
		}
		i = (integer) d;
		if (d==i && (((p&077777)*(q&077777))&040000)!=0) --i;
	} else {
		d -= 0.5;
		if (d<= -TWEXP31) {
			if (d!= -TWEXP31 || ((-(p&077777)*(q&077777))&040000)==0)
				aritherror = true;
			return -ELGORDO;
		}
		i = (integer) d;
		if (d==i && ((-(p&077777)*(q&077777))&040000)!=0) ++i;
	}
	return i;
}

integer
ztakescaled (integer p, integer q)		/* Approximate p*q/2^16 */
{	register double d;
	register integer i;
	d = (double)p * (double)q * TWEXP_16;
	if ((p^q) >= 0) {
		d += 0.5;
		if (d>=TWEXP31) {
			if (d!=TWEXP31 || (((p&077777)*(q&077777))&040000)==0)
				aritherror = true;
			return ELGORDO;
		}
		i = (integer) d;
		if (d==i && (((p&077777)*(q&077777))&040000)!=0) --i;
	} else {
		d -= 0.5;
		if (d<= -TWEXP31) {
			if (d!= -TWEXP31 || ((-(p&077777)*(q&077777))&040000)==0)
				aritherror = true;
			return -ELGORDO;
		}
		i = (integer) d;
		if (d==i && ((-(p&077777)*(q&077777))&040000)!=0) ++i;
	}
	return i;
}

/* Note that d cannot exactly equal TWEXP31 when the overflow test is made
   because the exact value of p/q cannot be strictly between (2^31-1)/2^28
   and 8/1.  No pair of integers less than 2^31 has such a ratio.
*/
integer
zmakefraction (integer p, integer q)	/* Approximate 2^28*p/q */
{	register double d;
	register integer i;
#ifdef DEBUG
	if (q==0) confusion(47); 
#endif /* DEBUG */
	d = TWEXP28 * (double)p /(double)q;
	if ((p^q) >= 0) {
		d += 0.5;
		if (d>=TWEXP31) {aritherror=true; return ELGORDO;}
		i = (integer) d;
		if (d==i && ( ((q>0 ? -q : q)&077777)
				* (((i&037777)<<1)-1) & 04000)!=0) --i;
	} else {
		d -= 0.5;
		if (d<= -TWEXP31) {aritherror=true; return -ELGORDO;}
		i = (integer) d;
		if (d==i && ( ((q>0 ? q : -q)&077777)
				* (((i&037777)<<1)+1) & 04000)!=0) ++i;
	}
	return i;
}

/* Note that d cannot exactly equal TWEXP31 when the overflow test is made
   because the exact value of p/q cannot be strictly between (2^31-1)/2^16
   and 2^15/1.  No pair of integers less than 2^31 has such a ratio.
*/
integer
zmakescaled (integer p, integer q)		/* Approximate 2^16*p/q */
{	register double d;
	register integer i;
#ifdef DEBUG
	if (q==0) confusion(47); 
#endif /* DEBUG */
	d = TWEXP16 * (double)p /(double)q;
	if ((p^q) >= 0) {
		d += 0.5;
		if (d>=TWEXP31) {aritherror=true; return ELGORDO;}
		i = (integer) d;
		if (d==i && ( ((q>0 ? -q : q)&077777)
				* (((i&037777)<<1)-1) & 04000)!=0) --i;
	} else {
		d -= 0.5;
		if (d<= -TWEXP31) {aritherror=true; return -ELGORDO;}
		i = (integer) d;
		if (d==i && ( ((q>0 ? q : -q)&077777)
				* (((i&037777)<<1)+1) & 04000)!=0) ++i;
	}
	return i;
}

#endif /* not FIXPT */
#endif /* not assembler */
#endif /* not TeX, i.e., MF */

#ifdef MF
/* On-line display routines for Metafont.  Here we use a dispatch table
   indexed by the MFTERM or TERM environment variable to select the
   graphics routines appropriate to the user's terminal.  stdout must be
   connected to a terminal for us to do any graphics.  */

#ifdef MFNOWIN
#undef AMIGAWIN
#undef EPSFWIN
#undef HP2627WIN
#undef MFTALKWIN
#undef NEXTWIN
#undef REGISWIN
#undef SUNWIN
#undef TEKTRONIXWIN
#undef UNITERMWIN
#undef WIN32WIN
#undef X11WIN
#endif

/* Prototypes for Metafont display routines: mf_XXX_initscreen,
   mf_XXX_updatescreen, mf_XXX_blankrectangle, and mf_XXX_paintrow.  */
#include <window/mfdisplay.h>

/* This variable, `mfwsw', contains the dispatch tables for each
   terminal.  We map the Pascal calls to the routines `init_screen',
   `update_screen', `blank_rectangle', and `paint_row' into the
   appropriate entry point for the specific terminal that MF is being
   run on.  */

struct mfwin_sw
{
  const char *mfwsw_type;	/* Name of terminal a la TERMCAP.  */
  int (*mfwsw_initscreen) (void);
  void (*mfwsw_updatescrn) (void);
  void (*mfwsw_blankrect) (screencol, screencol, screenrow, screenrow);
  void (*mfwsw_paintrow) (screenrow, pixelcolor, transspec, screencol);
} mfwsw[] =
{
#ifdef AMIGAWIN
  { "amiterm", mf_amiga_initscreen, mf_amiga_updatescreen,
    mf_amiga_blankrectangle, mf_amiga_paintrow },
#endif
#ifdef EPSFWIN
  { "epsf", mf_epsf_initscreen, mf_epsf_updatescreen, 
    mf_epsf_blankrectangle, mf_epsf_paintrow },
#endif
#ifdef HP2627WIN
  { "hp2627", mf_hp2627_initscreen, mf_hp2627_updatescreen,
    mf_hp2627_blankrectangle, mf_hp2627_paintrow },
#endif
#ifdef MFTALKWIN
  { "mftalk", mf_mftalk_initscreen, mf_mftalk_updatescreen, 
     mf_mftalk_blankrectangle, mf_mftalk_paintrow },
#endif
#ifdef NEXTWIN
  { "next", mf_next_initscreen, mf_next_updatescreen,
    mf_next_blankrectangle, mf_next_paintrow },
#endif
#ifdef REGISWIN
  { "regis", mf_regis_initscreen, mf_regis_updatescreen,
    mf_regis_blankrectangle, mf_regis_paintrow },
#endif
#ifdef SUNWIN
  { "sun", mf_sun_initscreen, mf_sun_updatescreen,
    mf_sun_blankrectangle, mf_sun_paintrow },
#endif
#ifdef TEKTRONIXWIN
  { "tek", mf_tektronix_initscreen, mf_tektronix_updatescreen,
    mf_tektronix_blankrectangle, mf_tektronix_paintrow },
#endif
#ifdef UNITERMWIN
   { "uniterm", mf_uniterm_initscreen, mf_uniterm_updatescreen,
     mf_uniterm_blankrectangle, mf_uniterm_paintrow },
#endif
#ifdef WIN32WIN
  { "win32term", mf_win32_initscreen, mf_win32_updatescreen, 
    mf_win32_blankrectangle, mf_win32_paintrow },
#endif
#ifdef X11WIN
  { "xterm", mf_x11_initscreen, mf_x11_updatescreen, 
    mf_x11_blankrectangle, mf_x11_paintrow },
#endif
  
  /* Always support this.  */
  { "trap", mf_trap_initscreen, mf_trap_updatescreen,
    mf_trap_blankrectangle, mf_trap_paintrow },

/* Finally, we must have an entry with a terminal type of NULL.  */
  { NULL, NULL, NULL, NULL, NULL }

}; /* End of the array initialization.  */


/* This is a pointer to the mfwsw[] entry that we find.  */
static struct mfwin_sw *mfwp;


/* The following are routines that just jump to the correct
   terminal-specific graphics code. If none of the routines in the
   dispatch table exist, or they fail, we produce trap-compatible
   output, i.e., the same words and punctuation that the unchanged
   mf.web would produce.  */


/* This returns true if we can do window operations, else false.  */

boolean
initscreen (void)
{
  /* If MFTERM is set, use it.  */
  const_string tty_type = kpse_var_value ("MFTERM");
  
  if (tty_type == NULL)
    { 
#if defined (AMIGA)
      tty_type = "amiterm";
#elif defined (WIN32)
      tty_type = "win32term";
#elif defined (OS2) || defined (__DJGPP__) /* not AMIGA nor WIN32 */
      tty_type = "mftalk";
#else /* not (OS2 or WIN32 or __DJGPP__ or AMIGA) */
      /* If DISPLAY is set, we are X11; otherwise, who knows.  */
      boolean have_display = getenv ("DISPLAY") != NULL;
      tty_type = have_display ? "xterm" : getenv ("TERM");

      /* If we don't know what kind of terminal this is, or if Metafont
         isn't being run interactively, don't do any online output.  */
      if (tty_type == NULL
          || (!STREQ (tty_type, "trap") && !isatty (fileno (stdout))))
        return 0;
#endif /* not (OS2 or WIN32 or __DJGPP__ or AMIGA) */
  }

  /* Test each of the terminals given in `mfwsw' against the terminal
     type, and take the first one that matches, or if the user is running
     under Emacs, the first one.  */
  for (mfwp = mfwsw; mfwp->mfwsw_type != NULL; mfwp++) {
    if (!strncmp (mfwp->mfwsw_type, tty_type, strlen (mfwp->mfwsw_type))
	|| STREQ (tty_type, "emacs")) {
      if (mfwp->mfwsw_initscreen)
	return ((*mfwp->mfwsw_initscreen) ());
      else {
        fprintf (stderr, "mf: Couldn't initialize online display for `%s'.\n",
                 tty_type);
        break;
      }
    }
  }
  
  /* We disable X support by default, since most sites don't use it, and
     variations in X configurations seem impossible to overcome
     automatically. Too frustrating for everyone involved.  */
  if (STREQ (tty_type, "xterm")) {
    fputs ("\nmf: Window support for X was not compiled into this binary.\n",
           stderr);
    fputs ("mf: There may be a binary called `mfw' on your system which\n",
           stderr);
    fputs ("mf: does contain X window support.\n\n", stderr);
    fputs ("mf: If you need to recompile, remember to give the --with-x\n",
           stderr);
    fputs ("mf: option to configure\n\n", stderr);
    fputs ("mf: (Or perhaps you just failed to specify the mode.)\n", stderr);
  }

  /* The current terminal type wasn't found in any of the entries, or
     initalization failed, so silently give up, assuming that the user
     isn't on a terminal that supports graphic output.  */
  return 0;
}


/* Make sure everything is visible.  */

void
updatescreen (void)
{
  if (mfwp->mfwsw_updatescrn)
    (*mfwp->mfwsw_updatescrn) ();
}


/* This sets the rectangle bounded by ([left,right], [top,bottom]) to
   the background color.  */

void
blankrectangle (screencol left, screencol right,
                screenrow top, screenrow bottom)
{
  if (mfwp->mfwsw_blankrect)
    (*mfwp->mfwsw_blankrect) (left, right, top, bottom);
}


/* This paints ROW, starting with the color INIT_COLOR. 
   TRANSITION_VECTOR then specifies the length of the run; then we
   switch colors.  This goes on for VECTOR_SIZE transitions.  */

void
paintrow (screenrow row, pixelcolor init_color,
          transspec transition_vector, screencol vector_size)
{
  if (mfwp->mfwsw_paintrow)
    (*mfwp->mfwsw_paintrow) (row, init_color, transition_vector, vector_size);
}
#endif /* MF */
