/* External procedures for these programs.  */

/* This includes <stdio.h> and "site.h".  */
#include "w2c-ext.h"

extern unsigned char xord[], xchr[];

/* These help to deal with Pascal vs. C strings.  */
void make_c_string (), make_pascal_string ();
void end_with_null (), end_with_space ();


/* Round R to the nearest whole number.  */
integer zround (r)
  double r;
{
  return r >= 0.0 ? (r + 0.5) : (r - 0.5);
}


/* Memory operations: variants of malloc(3) and realloc(3) that just
   give up the ghost when they fail. It is a very bad practice to call 
   system procs & not check for errors.
*/

extern char *malloc (), *realloc ();

char *xmalloc (size)
  unsigned size;
{
  char *mem = malloc (size);
  
  if (mem == NULL)
    {
      fprintf (stderr, "! Cannot allocate %u bytes.\n", size);
      exit (10);
    }
  
  return mem;
}


char * xrealloc (ptr, size)
  char *ptr;
  unsigned size;
{
  char *mem = realloc (ptr, size);
  
  if (mem == NULL)
    {
      fprintf (stderr, "! Cannot reallocate %u bytes at %x.\n", size, ptr);
      exit (10);
    }
    
  return mem;
}


/* String operations.  */   
   
/* Deal with C and Pascal strings.  */

/* Change the Pascal string P_STRING into a C string; i.e., make it
   start after the leading character Pascal puts in, and terminate it
   with a null.  We also have to convert from the internal character set
   (ASCII) to the external character set, if we're running on a
   non-ASCII system.
*/ 
void make_c_string (p_string)
  char **p_string;
{
  (*p_string)++;
  end_with_null (*p_string);
}


/* Replace the first space we come to with a null.
*/
void end_with_null (s)
 char *s;
{
  for ( ; *s != ' '; s++)
#ifdef NONASCII
    *s = xchr[*s]
#endif
    ;
  *s = '\0';
}


/* Change the C string C_STRING into a Pascal string; i.e., make it
   start one character before it does now (so C_STRING had better have
   been a Pascal string originally), and terminate with a space.  We
   also convert back from the external character set to the internal
   character set (ASCII), if we're running on a non-ASCII system.
*/
void make_pascal_string (c_string)
  char **c_string;
{
  end_with_space (*c_string);
  (*c_string)--;
}

/* Replace the first null we come to with a space.
*/
void end_with_space (s)
  char *s;
{
  for ( ; *s != '\0' ; s++)
#ifdef NONASCII
    *s = xchr[*s]
#endif
    ;
  
  *s = ' ';
}


/* Change the suffix of BASE (a Pascal string) to be SUFFIX (another
   Pascal string).  We have to change them to C strings to do the work,
   then convert them back to Pascal strings.
*/
void makesuffix (base, suffix)
  char *base;
  char *suffix;
{
  char *last_dot, *last_slash;
  make_c_string (&base);
  
  last_dot = rindex (base, '.');
  last_slash = rindex (base, '/');
  
  if (last_dot == NULL || last_dot < last_slash) /* Add the suffix?  */
    {
      make_c_string (&suffix);
      strcat (base, suffix);
      make_pascal_string (&suffix);
    }
    
  make_pascal_string (&base);
}


/* Insert the string INSERTION into TARGET before the index WHERE.  We
   assume that TARGET is large enough to hold the result.  
*/
static void insert_string (target, where, insertion)
  char target[];
  int where;
  char *insertion;
{
  int i;
  unsigned insertion_length = strlen (insertion);
  unsigned target_length = strlen (target);
  
  for (i = target_length; i >= where; i--)
    target[i + insertion_length] = target[i];

  strncpy (target + where, insertion, insertion_length);
}



/* Path searching. */

#define NUMBER_OF_PATHS 11

static char *path[NUMBER_OF_PATHS];
static char *env_var_names[NUMBER_OF_PATHS]
  = { "BIBINPUTS", "GFFONTS", "MFBASES", "MFINPUTS", "MFPOOL",
      "PKFONTS", "TEXFORMATS", "TEXINPUTS", "TEXPOOL",
      "TEXFONTS", "VFFONTS"
    };

#define READ_ACCESS 4       /* Used in access(2) call.  */

/* What separates elements of the path variables.  */
#ifdef MS_DOS
#define PATH_DELIMITER ';'
#else
#define PATH_DELIMITER ':'
#endif

/* We will need some system include files to deal with directories.  */
#ifdef SEARCH_SUBDIRECTORIES
#include <sys/types.h>
#include <sys/stat.h>
#ifdef SYSV
#include <dirent.h>
typedef struct dirent *directory_entry_type;
#else
#include <sys/dir.h>
typedef struct direct *directory_entry_type;
#endif /* not SYSV */

/* Declare getcwd(3).  */
extern char *getcwd ();
extern int errno;
#endif /* SEARCH_SUBDIRECTORIES */


/* Subroutines.  */
static void next_component ();
int is_dir ();

/* Says where NAME is ok to open for reading.  */
#define READABLE_FILE(name) access (name, READ_ACCESS) == 0 && !is_dir (name)


/* This routine initializes `path[PATH_INDEX]'.  If the environment
   variable `env_var_names[PATH_INDEX]' is not set, we simply use 
   DEFAULT_VALUE.  Otherwise, we use the value of the environment
   variable, and then replace any ``extra'' colons with DEFAULT_VALUE. 

   For example, if DEFAULT_VALUE is `foo', and the environment variable
   value is `:bar::baz:', the final result will be
   `foo:bar:foo:baz:foo'.  (Of course, it is pointless to have more than
   one extra `:' in practice, but the point is that it can be anywhere.)
   
   If subdirectory searching has been compiled (by defining
   SEARCH_SUBDIRECTORIES), and SUBDIR_FLAG so indicates, we look at each
   directory in the path and add all subdirectories we find to the end
   of the path.  This is somewhat less efficient when we are looking for
   only one file, and the file would be found early in the path, but is
   far more efficient when we look up many files using the same path.  */

/* Values for SUBDIR_FLAG.  */
#define SUBDIR_NO_CHECK 0
#define SUBDIR_ALWAYS_CHECK 1
#define SUBDIR_CHECK_IF_NOT_DEFAULT 2

static void
do_path (path_index, default_value, subdir_flag)
  unsigned path_index;
  char *default_value;
  int subdir_flag;
{
  char *temp;
  char *the_path;

  temp = getenv (env_var_names[path_index]);
  if (temp == NULL)
    /* This doesn't actually assign into the array, but it doesn't
       matter.  */
    the_path = default_value;
  else
    { /* Replace extra `:'s with the system default.  */
      the_path = xmalloc (strlen (temp) + 1);
      strcpy (the_path, temp);
      
      if (*the_path == PATH_DELIMITER)
        {
          the_path = xrealloc (the_path, strlen (the_path) 
                                         + strlen (default_value) + 1);
          insert_string (the_path, 0, default_value);
        }
      if (*(the_path + strlen (the_path) - 1) == PATH_DELIMITER)
        {
          the_path = xrealloc (the_path, strlen (the_path)
                                         + strlen (default_value) + 1);
          strcat (the_path, default_value);
        }
      while ((temp = index (temp, PATH_DELIMITER)) != NULL)
        {
          temp++;
          if (*temp == PATH_DELIMITER)
            {
              the_path = xrealloc (the_path, strlen (the_path)
                                             + strlen (default_value) + 1);
              insert_string (the_path, temp - the_path, default_value);
              temp++;
            }
        }
    }

  /* Assign to the final resting place.  */
  path[path_index] = xmalloc (strlen (the_path) + 1);
  strcpy (path[path_index], the_path);

#ifdef SEARCH_SUBDIRECTORIES
  /* At this point, `path[path_index]' is the colon-separated list of
     directories to search.  We want to add all the subdirectories
     directly below each of those directories.  */
  if (subdir_flag == SUBDIR_ALWAYS_CHECK
      || (subdir_flag == SUBDIR_CHECK_IF_NOT_DEFAULT
          && the_path != default_value))
    {
      DIR *dir;
      directory_entry_type e;
      char dirname[FILENAMESIZE];

      /* Unfortunately, we can't look in the environment for the current
         directory, because if we are running under a program (let's say
         Emacs), the PWD variable might have been set by Emacs' parent
         to the current directory at the time Emacs was invoked.  This
         is not necessarily the same directory the user expects to be
         in.  So, we must always call getcwd(3), even though it is slow
         and prone to hang in networked installations.  */
      char *cwd = getcwd (NULL, FILENAMESIZE + 2);
      if (cwd == NULL)
        {
          perror ("getcwd");
          exit (errno);
        }

      temp = xmalloc (strlen (path[path_index]) + 1);
      strcpy (temp, path[path_index]);

      do
        {
          next_component (dirname, &temp);

          /* All the `::'s should be gone by now, but we may as well make
             sure `opendir' doesn't crash.  */
          if (*dirname == 0) continue;

          /* By changing directories, we save a bunch of string
             concatenations (and make the pathnames the kernel looks up
             shorter).  */
          if (chdir (dirname) != 0) continue;
          
          dir = opendir (".");
          if (dir == NULL) continue;

          while ((e = readdir (dir)) != NULL)
            {
              if (is_dir (e->d_name) && strcmp (e->d_name, ".") != 0
                  && strcmp (e->d_name, "..") != 0)
                {
                  unsigned len = strlen (path[path_index]);
                  char potential[FILENAMESIZE];
                  strcpy (potential, dirname);
                  strcat (potential, "/");
                  strcat (potential, e->d_name);

                  path[path_index] = xrealloc (path[path_index],
                                               len + strlen (potential) + 2);

                  len = strlen (path[path_index]);
                  *(path[path_index] + len) = PATH_DELIMITER;
                  *(path[path_index] + len + 1) = 0;
                  strcat (path[path_index], potential);
                }
            }
          closedir (dir);
          
          /* Change back to the current directory, in case the path
             contains relative directory names.  */
          if (chdir (cwd) != 0)
            {
              perror (cwd);
              exit (errno);
            }
        }
      while (*temp != 0);
    }
#endif
}


/* This sets up the paths, by either copying from an environment variable
   or using the default path, which is defined as a preprocessor symbol
   (with the same name as the environment variable) in `site.h'.  The
   parameter PATH_BITS is a logical or of the paths we need to set.
*/
extern void
setpaths (path_bits)
  int path_bits;
{
  /* We must assign to the TFM file path before doing any of the other
     font paths, since it is used as a default.  */
  if (path_bits
      & (TFMFILEPATHBIT | GFFILEPATHBIT | PKFILEPATHBIT | VFFILEPATHBIT))
    do_path (TFMFILEPATH, TEXFONTS, SUBDIR_ALWAYS_CHECK);

  if (path_bits & BIBINPUTPATHBIT)
    do_path (BIBINPUTPATH, BIBINPUTS, SUBDIR_NO_CHECK);

  if (path_bits & GFFILEPATHBIT)
    do_path (GFFILEPATH, path[TFMFILEPATH], SUBDIR_CHECK_IF_NOT_DEFAULT);

  if (path_bits & MFBASEPATHBIT)
    do_path (MFBASEPATH, MFBASES, SUBDIR_NO_CHECK);

  if (path_bits & MFINPUTPATHBIT)
    do_path (MFINPUTPATH, MFINPUTS, SUBDIR_ALWAYS_CHECK);

  if (path_bits & MFPOOLPATHBIT)
    do_path (MFPOOLPATH, MFPOOL, SUBDIR_NO_CHECK);

  if (path_bits & PKFILEPATHBIT)
    do_path (PKFILEPATH, path[TFMFILEPATH], SUBDIR_CHECK_IF_NOT_DEFAULT);

  if (path_bits & TEXFORMATPATHBIT)
    do_path (TEXFORMATPATH, TEXFORMATS, SUBDIR_NO_CHECK);

  if (path_bits & TEXINPUTPATHBIT)
    do_path (TEXINPUTPATH, TEXINPUTS, SUBDIR_ALWAYS_CHECK);

  if (path_bits & TEXPOOLPATHBIT)
    do_path (TEXPOOLPATH, TEXPOOL, SUBDIR_NO_CHECK);

  if (path_bits & VFFILEPATHBIT)
    do_path (VFFILEPATH, path[TFMFILEPATH], SUBDIR_CHECK_IF_NOT_DEFAULT);
}


/* Look for NAME, a Pascal string, in a colon-separated list of
   directories.  The path to use is given (indirectly) by PATH_INDEX.
   If the search is successful, leave the full pathname in NAME (which
   therefore must have enough room for such a pathname), padded with
   blanks.  Otherwise, or if NAME is an absolute or relative pathname,
   just leave it alone.
*/
boolean
testreadaccess (name, path_index)
  char *name;
  int path_index;
{
  char potential[FILENAMESIZE];
  int ok = 0;
  char *the_path = path[path_index];
  char *saved_path = the_path;
  
  make_c_string (&name);

  if (*name == '/' || *name == '~'
      || (*name == '.' && *(name + 1) == '/')
      || (*name == '.' && *(name + 1) == '.' && *(name + 2) == '/'))
    ok = READABLE_FILE (name); 
  else
    {
      do
	{
	  next_component (potential, &the_path);

          if (*potential != 0)
            {
              strcat (potential, "/");
	      strcat (potential, name);
	      ok = READABLE_FILE (potential);
            }
	}
      while (!ok && *the_path != 0);

      /* If we found it, leave the answer in NAME.  */
      if (ok)
        strcpy (name, potential);
    }
  
  make_pascal_string (&name);
  
  return ok;
}


/* Return, in NAME, the next component of PATH, i.e., the characters up
   to the next PATH_DELIMITER.
*/
static void next_component (name, path)
  char name[];
  char **path;
{
  unsigned count = 0;
  
  while (**path != 0 && **path != PATH_DELIMITER)
    {
      name[count++] = **path;
      (*path)++; /* Move further along, even between calls.  */
    }
  
  name[count] = 0;
  if (**path == PATH_DELIMITER)
    (*path)++; /* Move past the delimiter.  */
}



/* Return true if FN is a directory or a symlink to a directory,
   false if not.
*/
int
is_dir (fn)
  char *fn;
{
  struct stat stats;

  return stat (fn, &stats) == 0 && (stats.st_mode & S_IFMT) == S_IFDIR;
}



/* File operations.  */

/* Open a file; don't return if any error occurs.  NAME is a Pascal
   string, but is changed to a C string and not changed back.  
   RMD: I do want it changed back
*/ 
FILE * checked_fopen (name, mode)
  char *name;
  char *mode;
{
  FILE *result;
  char *cp;

  make_c_string (&name);
  
  result = fopen (name, mode);
  if (result != NULL) {
    make_pascal_string (&name);
    return result;}
    
  perror (name);
  exit (1);
  /*NOTREACHED*/
}


/* Return true if we're at the end of FILE, else false.  This implements
   Pascal's `eof' builtin.
*/
boolean test_eof (file) 
  text file;
{
  register int c;
  FILE *ff ;
  /* Maybe we're already at the end?  */
  ff = *file ;
  if (feof( ff))
    return true;

  if ((c = getc (*file)) == EOF)
    return true;

  /* Whoops, we weren't at the end.  Back up.  */
  (void) ungetc (c, *file);

  return false;
}


/* Return true on end-of-line in FILE or at the end of FILE, else false.
*/

boolean eoln (file)
  text file;
{
  register int c;

  if (feof (*file))
    return true;
  
  c = getc (*file);
  
  if (c != EOF)
    (void) ungetc (c, *file);
    
  return c == '\n' || c == EOF;
}


/* Print real number R in the Pascal format N:M on the file F.
RMD: these procs not used; I made web2c generate proper write statements.
*/
void fprintreal (f, r, n, m)
  text f;
  double r;
  int n, m;
{
  char fmt[50];  /* Surely enough, since N and M won't be more than 25
                    digits each!  */

  (void) sprintf (fmt, "%%%d.%dlf", n, m);
  (void) fprintf (*f, fmt, r);
}


/* Print S, a Pascal string, on the file F.  It starts at index 1 and is
   terminated by a space.
*/
static void fprint_pascal_string (s, f)
  char *s;
  FILE *f;
{
  s++;
  while (*s != ' ') putc (*s++, f);
}

/* Print S, a Pascal string, on stdout.
*/
void printpascalstring (s)
  char *s;
{
  fprint_pascal_string (s, stdout);
}

/* Ditto, for stderr.
*/
void errprintpascalstring (s)
  char *s;
{
  fprint_pascal_string (s, stderr);
}

/* Read an integer from the file F, reading past the subsequent end of
   line.
*/
integer inputint (f)
  text f;
{
  char buffer[50]; /* Long enough for anything reasonable.  */

  return
    fgets (buffer, sizeof (buffer), *f)
    ? atoi (buffer)
    : 0;
}

/* Read three integers from stdin.
*/
void zinput3ints (a,b,c)
  integer *a, *b, *c;
{
  while (scanf ("%ld %ld %ld\n", a, b, c) != 3)
    (void) fprintf (stderr, "Please enter three integers.\n");
}