termcap.c

UNIX下SH的实现源码

  return SYS$PARSE(&fab, 0, 0) == RMS$_NORMAL;
}

#else /* !VMS */

#if defined (__MSDOS__)
static int
valid_filename_p (fn)
     char *fn;
{
  return *fn == '\\' || *fn == '/' ||
    (*fn >= 'A' && *fn <= 'z' && fn[1] == ':');
}
#else
#define valid_filename_p(fn) (*(fn) == '/')
#endif

#endif /* !VMS */

/* Find the termcap entry data for terminal type NAME
   and store it in the block that BP points to.
   Record its address for future use.

   If BP is null, space is dynamically allocated.

   Return -1 if there is some difficulty accessing the data base
   of terminal types,
   0 if the data base is accessible but the type NAME is not defined
   in it, and some other value otherwise.  */

__private_extern__
int
tgetent (bp, name)
     char *bp, *name;
{
  register char *termcap_name;
  register int fd;
  struct buffer buf;
  register char *bp1;
  char *bp2;
  char *term;
  int malloc_size = 0;
  register int c;
  char *tcenv;			/* TERMCAP value, if it contains :tc=.  */
  char *indirect = NULL;	/* Terminal type in :tc= in TERMCAP value.  */
  int filep;

#ifdef INTERNAL_TERMINAL
  /* For the internal terminal we don't want to read any termcap file,
     so fake it.  */
  if (!strcmp (name, "internal"))
    {
      term = INTERNAL_TERMINAL;
      if (!bp)
	{
	  malloc_size = 1 + strlen (term);
	  bp = (char *) xmalloc (malloc_size);
	}
      strcpy (bp, term);
      goto ret;
    }
#endif /* INTERNAL_TERMINAL */

  /* For compatibility with programs like `less' that want to
     put data in the termcap buffer themselves as a fallback.  */
  if (bp)
    term_entry = bp;

  termcap_name = getenv ("TERMCAP");
  if (termcap_name && *termcap_name == '\0')
    termcap_name = NULL;
#if 0
#if defined (MSDOS) && !defined (TEST)
  if (termcap_name && (*termcap_name == '\\'
		       || *termcap_name == '/'
		       || termcap_name[1] == ':'))
    dostounix_filename(termcap_name);
#endif
#endif

  filep = termcap_name && valid_filename_p (termcap_name);

  /* If termcap_name is non-null and starts with / (in the un*x case, that is),
     it is a file name to use instead of /etc/termcap.
     If it is non-null and does not start with /,
     it is the entry itself, but only if
     the name the caller requested matches the TERM variable.  */

  if (termcap_name && !filep && !strcmp (name, getenv ("TERM")))
    {
      indirect = tgetst1 (find_capability (termcap_name, "tc"), (char **) 0);
      if (!indirect)
	{
	  if (!bp)
	    bp = termcap_name;
	  else
	    strcpy (bp, termcap_name);
	  goto ret;
	}
      else
	{			/* It has tc=.  Need to read /etc/termcap.  */
	  tcenv = termcap_name;
 	  termcap_name = NULL;
	}
    }

  if (!termcap_name || !filep)
    termcap_name = TERMCAP_FILE;

  /* Here we know we must search a file and termcap_name has its name.  */

#ifdef MSDOS
  fd = open (termcap_name, O_RDONLY|O_TEXT, 0);
#else
  fd = open (termcap_name, O_RDONLY, 0);
#endif
  if (fd < 0)
    return -1;

  buf.size = BUFSIZE;
  /* Add 1 to size to ensure room for terminating null.  */
  buf.beg = (char *) xmalloc (buf.size + 1);
  term = indirect ? indirect : name;

  if (!bp)
    {
      malloc_size = indirect ? strlen (tcenv) + 1 : buf.size;
      bp = (char *) xmalloc (malloc_size);
    }
  bp1 = bp;

  if (indirect)
    /* Copy the data from the environment variable.  */
    {
      strcpy (bp, tcenv);
      bp1 += strlen (tcenv);
    }

  while (term)
    {
      /* Scan the file, reading it via buf, till find start of main entry.  */
      if (scan_file (term, fd, &buf) == 0)
	{
	  close (fd);
	  free (buf.beg);
	  if (malloc_size)
	    free (bp);
	  return 0;
	}

      /* Free old `term' if appropriate.  */
      if (term != name)
	free (term);

      /* If BP is malloc'd by us, make sure it is big enough.  */
      if (malloc_size)
	{
	  malloc_size = bp1 - bp + buf.size;
	  termcap_name = (char *) xrealloc (bp, malloc_size);
	  bp1 += termcap_name - bp;
	  bp = termcap_name;
	}

      bp2 = bp1;

      /* Copy the line of the entry from buf into bp.  */
      termcap_name = buf.ptr;
      while ((*bp1++ = c = *termcap_name++) && c != '\n')
	/* Drop out any \ newline sequence.  */
	if (c == '\\' && *termcap_name == '\n')
	  {
	    bp1--;
	    termcap_name++;
	  }
      *bp1 = '\0';

      /* Does this entry refer to another terminal type's entry?
	 If something is found, copy it into heap and null-terminate it.  */
      term = tgetst1 (find_capability (bp2, "tc"), (char **) 0);
    }

  close (fd);
  free (buf.beg);

  if (malloc_size)
    bp = (char *) xrealloc (bp, bp1 - bp + 1);

 ret:
  term_entry = bp;
  return 1;
}

/* Given file open on FD and buffer BUFP,
   scan the file from the beginning until a line is found
   that starts the entry for terminal type STR.
   Return 1 if successful, with that line in BUFP,
   or 0 if no entry is found in the file.  */

static int
scan_file (str, fd, bufp)
     char *str;
     int fd;
     register struct buffer *bufp;
{
  register char *end;

  bufp->ptr = bufp->beg;
  bufp->full = 0;
  bufp->ateof = 0;
  *bufp->ptr = '\0';

  lseek (fd, 0L, 0);

  while (!bufp->ateof)
    {
      /* Read a line into the buffer.  */
      end = NULL;
      do
	{
	  /* if it is continued, append another line to it,
	     until a non-continued line ends.  */
	  end = gobble_line (fd, bufp, end);
	}
      while (!bufp->ateof && end[-2] == '\\');

      if (*bufp->ptr != '#'
	  && name_match (bufp->ptr, str))
	return 1;

      /* Discard the line just processed.  */
      bufp->ptr = end;
    }
  return 0;
}

/* Return nonzero if NAME is one of the names specified
   by termcap entry LINE.  */

static int
name_match (line, name)
     char *line, *name;
{
  register char *tem;

  if (!compare_contin (line, name))
    return 1;
  /* This line starts an entry.  Is it the right one?  */
  for (tem = line; *tem && *tem != '\n' && *tem != ':'; tem++)
    if (*tem == '|' && !compare_contin (tem + 1, name))
      return 1;

  return 0;
}

static int
compare_contin (str1, str2)
     register char *str1, *str2;
{
  register int c1, c2;
  while (1)
    {
      c1 = *str1++;
      c2 = *str2++;
      while (c1 == '\\' && *str1 == '\n')
	{
	  str1++;
	  while ((c1 = *str1++) == ' ' || c1 == '\t');
	}
      if (c2 == '\0')
	{
	  /* End of type being looked up.  */
	  if (c1 == '|' || c1 == ':')
	    /* If end of name in data base, we win.  */
	    return 0;
	  else
	    return 1;
        }
      else if (c1 != c2)
	return 1;
    }
}

/* Make sure that the buffer <- BUFP contains a full line
   of the file open on FD, starting at the place BUFP->ptr
   points to.  Can read more of the file, discard stuff before
   BUFP->ptr, or make the buffer bigger.

   Return the pointer to after the newline ending the line,
   or to the end of the file, if there is no newline to end it.

   Can also merge on continuation lines.  If APPEND_END is
   non-null, it points past the newline of a line that is
   continued; we add another line onto it and regard the whole
   thing as one line.  The caller decides when a line is continued.  */

static char *
gobble_line (fd, bufp, append_end)
     int fd;
     register struct buffer *bufp;
     char *append_end;
{
  register char *end;
  register int nread;
  register char *buf = bufp->beg;
  register char *tem;

  if (!append_end)
    append_end = bufp->ptr;

  while (1)
    {
      end = append_end;
      while (*end && *end != '\n') end++;
      if (*end)
        break;
      if (bufp->ateof)
	return buf + bufp->full;
      if (bufp->ptr == buf)
	{
	  if (bufp->full == bufp->size)
	    {
	      bufp->size *= 2;
	      /* Add 1 to size to ensure room for terminating null.  */
	      tem = (char *) xrealloc (buf, bufp->size + 1);
	      bufp->ptr = (bufp->ptr - buf) + tem;
	      append_end = (append_end - buf) + tem;
	      bufp->beg = buf = tem;
	    }
	}
      else
	{
	  append_end -= bufp->ptr - buf;
	  bcopy (bufp->ptr, buf, bufp->full -= bufp->ptr - buf);
	  bufp->ptr = buf;
	}
      if (!(nread = read (fd, buf + bufp->full, bufp->size - bufp->full)))
	bufp->ateof = 1;
      bufp->full += nread;
      buf[bufp->full] = '\0';
    }
  return end + 1;
}

#ifdef TEST

#ifdef NULL
#undef NULL
#endif

#include <stdio.h>

main (argc, argv)
     int argc;
     char **argv;
{
  char *term;
  char *buf;

  term = argv[1];
  printf ("TERM: %s\n", term);

  buf = (char *) tgetent (0, term);
  if ((int) buf <= 0)
    {
      printf ("No entry.\n");
      return 0;
    }

  printf ("Entry: %s\n", buf);

  tprint ("cm");
  tprint ("AL");

  printf ("co: %d\n", tgetnum ("co"));
  printf ("am: %d\n", tgetflag ("am"));
}

tprint (cap)
     char *cap;
{
  char *x = tgetstr (cap, 0);
  register char *y;

  printf ("%s: ", cap);
  if (x)
    {
      for (y = x; *y; y++)
	if (*y <= ' ' || *y == 0177)
	  printf ("\\%0o", *y);
	else
	  putchar (*y);
      free (x);
    }
  else
    printf ("none");
  putchar ('\n');
}

#endif /* TEST */