+/* Variables to keep track of the expanded prompt string, which may
+ include invisible characters. */
+
+static char *local_prompt, *local_prompt_prefix;
+static int prompt_visible_length, prompt_prefix_length;
+
+/* The number of invisible characters in the line currently being
+ displayed on the screen. */
+static int visible_wrap_offset;
+
+/* The number of invisible characters in the prompt string. Static so it
+ can be shared between rl_redisplay and update_line */
+static int wrap_offset;
+
+/* The index of the last invisible character in the prompt string. */
+static int prompt_last_invisible;
+
+/* The length (buffer offset) of the first line of the last (possibly
+ multi-line) buffer displayed on the screen. */
+static int visible_first_line_len;
+
+/* Number of invisible characters on the first physical line of the prompt.
+ Only valid when the number of physical characters in the prompt exceeds
+ (or is equal to) _rl_screenwidth. */
+static int prompt_invis_chars_first_line;
+
+static int prompt_last_screen_line;
+
+static int prompt_physical_chars;
+
+/* Variables to save and restore prompt and display information. */
+
+/* These are getting numerous enough that it's time to create a struct. */
+
+static char *saved_local_prompt;
+static char *saved_local_prefix;
+static int saved_last_invisible;
+static int saved_visible_length;
+static int saved_prefix_length;
+static int saved_invis_chars_first_line;
+static int saved_physical_chars;
+
+/* Expand the prompt string S and return the number of visible
+ characters in *LP, if LP is not null. This is currently more-or-less
+ a placeholder for expansion. LIP, if non-null is a place to store the
+ index of the last invisible character in the returned string. NIFLP,
+ if non-zero, is a place to store the number of invisible characters in
+ the first prompt line. The previous are used as byte counts -- indexes
+ into a character buffer. */
+
+/* Current implementation:
+ \001 (^A) start non-visible characters
+ \002 (^B) end non-visible characters
+ all characters except \001 and \002 (following a \001) are copied to
+ the returned string; all characters except those between \001 and
+ \002 are assumed to be `visible'. */
+
+static char *
+expand_prompt (pmt, lp, lip, niflp, vlp)
+ char *pmt;
+ int *lp, *lip, *niflp, *vlp;
+{
+ char *r, *ret, *p;
+ int l, rl, last, ignoring, ninvis, invfl, invflset, ind, pind, physchars;
+
+ /* Short-circuit if we can. */
+ if ((MB_CUR_MAX <= 1 || rl_byte_oriented) && strchr (pmt, RL_PROMPT_START_IGNORE) == 0)
+ {
+ r = savestring (pmt);
+ if (lp)
+ *lp = strlen (r);
+ if (lip)
+ *lip = 0;
+ if (niflp)
+ *niflp = 0;
+ if (vlp)
+ *vlp = lp ? *lp : strlen (r);
+ return r;
+ }
+
+ l = strlen (pmt);
+ r = ret = (char *)xmalloc (l + 1);
+
+ invfl = 0; /* invisible chars in first line of prompt */
+ invflset = 0; /* we only want to set invfl once */
+
+ for (rl = ignoring = last = ninvis = physchars = 0, p = pmt; p && *p; p++)
+ {
+ /* This code strips the invisible character string markers
+ RL_PROMPT_START_IGNORE and RL_PROMPT_END_IGNORE */
+ if (*p == RL_PROMPT_START_IGNORE)
+ {
+ ignoring++;
+ continue;
+ }
+ else if (ignoring && *p == RL_PROMPT_END_IGNORE)
+ {
+ ignoring = 0;
+ if (p[-1] != RL_PROMPT_START_IGNORE)
+ last = r - ret - 1;
+ continue;
+ }
+ else
+ {
+#if defined (HANDLE_MULTIBYTE)
+ if (MB_CUR_MAX > 1 && rl_byte_oriented == 0)
+ {
+ pind = p - pmt;
+ ind = _rl_find_next_mbchar (pmt, pind, 1, MB_FIND_NONZERO);
+ l = ind - pind;
+ while (l--)
+ *r++ = *p++;
+ if (!ignoring)
+ {
+ rl += ind - pind;
+ physchars += _rl_col_width (pmt, pind, ind);
+ }
+ else
+ ninvis += ind - pind;
+ p--; /* compensate for later increment */
+ }
+ else
+#endif
+ {
+ *r++ = *p;
+ if (!ignoring)
+ {
+ rl++; /* visible length byte counter */
+ physchars++;
+ }
+ else
+ ninvis++; /* invisible chars byte counter */
+ }
+
+ if (invflset == 0 && rl >= _rl_screenwidth)
+ {
+ invfl = ninvis;
+ invflset = 1;
+ }
+ }
+ }
+
+ if (rl < _rl_screenwidth)
+ invfl = ninvis;
+
+ *r = '\0';
+ if (lp)
+ *lp = rl;
+ if (lip)
+ *lip = last;
+ if (niflp)
+ *niflp = invfl;
+ if (vlp)
+ *vlp = physchars;
+ return ret;
+}
+
+/* Just strip out RL_PROMPT_START_IGNORE and RL_PROMPT_END_IGNORE from
+ PMT and return the rest of PMT. */
+char *
+_rl_strip_prompt (pmt)
+ char *pmt;
+{
+ char *ret;
+
+ ret = expand_prompt (pmt, (int *)NULL, (int *)NULL, (int *)NULL, (int *)NULL);
+ return ret;
+}
+
+/*
+ * Expand the prompt string into the various display components, if
+ * necessary.
+ *
+ * local_prompt = expanded last line of string in rl_display_prompt
+ * (portion after the final newline)
+ * local_prompt_prefix = portion before last newline of rl_display_prompt,
+ * expanded via expand_prompt
+ * prompt_visible_length = number of visible characters in local_prompt
+ * prompt_prefix_length = number of visible characters in local_prompt_prefix
+ *
+ * This function is called once per call to readline(). It may also be
+ * called arbitrarily to expand the primary prompt.
+ *
+ * The return value is the number of visible characters on the last line
+ * of the (possibly multi-line) prompt.
+ */
+int
+rl_expand_prompt (prompt)
+ char *prompt;
+{
+ char *p, *t;
+ int c;
+
+ /* Clear out any saved values. */
+ FREE (local_prompt);
+ FREE (local_prompt_prefix);
+
+ local_prompt = local_prompt_prefix = (char *)0;
+ prompt_last_invisible = prompt_invis_chars_first_line = 0;
+ prompt_visible_length = prompt_physical_chars = 0;
+
+ if (prompt == 0 || *prompt == 0)
+ return (0);
+
+ p = strrchr (prompt, '\n');
+ if (!p)
+ {
+ /* The prompt is only one logical line, though it might wrap. */
+ local_prompt = expand_prompt (prompt, &prompt_visible_length,
+ &prompt_last_invisible,
+ &prompt_invis_chars_first_line,
+ &prompt_physical_chars);
+ local_prompt_prefix = (char *)0;
+ return (prompt_visible_length);
+ }
+ else
+ {
+ /* The prompt spans multiple lines. */
+ t = ++p;
+ local_prompt = expand_prompt (p, &prompt_visible_length,
+ &prompt_last_invisible,
+ (int *)NULL,
+ &prompt_physical_chars);
+ c = *t; *t = '\0';
+ /* The portion of the prompt string up to and including the
+ final newline is now null-terminated. */
+ local_prompt_prefix = expand_prompt (prompt, &prompt_prefix_length,
+ (int *)NULL,
+ &prompt_invis_chars_first_line,
+ (int *)NULL);
+ *t = c;
+ return (prompt_prefix_length);
+ }
+}
+
+/* Initialize the VISIBLE_LINE and INVISIBLE_LINE arrays, and their associated
+ arrays of line break markers. MINSIZE is the minimum size of VISIBLE_LINE
+ and INVISIBLE_LINE; if it is greater than LINE_SIZE, LINE_SIZE is
+ increased. If the lines have already been allocated, this ensures that
+ they can hold at least MINSIZE characters. */
+static void
+init_line_structures (minsize)
+ int minsize;
+{
+ register int n;
+
+ if (invisible_line == 0) /* initialize it */
+ {
+ if (line_size < minsize)
+ line_size = minsize;
+ visible_line = (char *)xmalloc (line_size);
+ invisible_line = (char *)xmalloc (line_size);
+ }
+ else if (line_size < minsize) /* ensure it can hold MINSIZE chars */
+ {
+ line_size *= 2;
+ if (line_size < minsize)
+ line_size = minsize;
+ visible_line = (char *)xrealloc (visible_line, line_size);
+ invisible_line = (char *)xrealloc (invisible_line, line_size);
+ }
+
+ for (n = minsize; n < line_size; n++)
+ {
+ visible_line[n] = 0;
+ invisible_line[n] = 1;
+ }
+
+ if (vis_lbreaks == 0)
+ {
+ /* should be enough. */
+ inv_lbsize = vis_lbsize = 256;
+ inv_lbreaks = (int *)xmalloc (inv_lbsize * sizeof (int));
+ vis_lbreaks = (int *)xmalloc (vis_lbsize * sizeof (int));
+#if defined (HANDLE_MULTIBYTE)
+ _rl_wrapped_line = (int *)xmalloc (vis_lbsize * sizeof (int));
+#endif
+ inv_lbreaks[0] = vis_lbreaks[0] = 0;
+ }
+}
+