/****************************************************************************
 * Copyright 2018-2024,2025 Thomas E. Dickey                                *
 * Copyright 1998-2016,2017 Free Software Foundation, Inc.                  *
 *                                                                          *
 * Copyright (c) 2026                                                       *
 * Project Tick. All rights reserved.                                       *
 *                                                                          *
 * Permission is hereby granted, free of charge, to any person obtaining a  *
 * copy of this software and associated documentation files (the            *
 * "Software"), to deal in the Software without restriction, including      *
 * without limitation the rights to use, copy, modify, merge, publish,      *
 * distribute, distribute with modifications, sublicense, and/or sell       *
 * copies of the Software, and to permit persons to whom the Software is    *
 * furnished to do so, subject to the following conditions:                 *
 *                                                                          *
 * The above copyright notice and this permission notice shall be included  *
 * in all copies or substantial portions of the Software.                   *
 *                                                                          *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS  *
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF               *
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.   *
 * IN NO EVENT SHALL THE ABOVE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,   *
 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR    *
 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR    *
 * THE USE OR OTHER DEALINGS IN THE SOFTWARE.                               *
 *                                                                          *
 * Except as contained in this notice, the name(s) of the above copyright   *
 * holders shall not be used in advertising or otherwise to promote the     *
 * sale, use or other dealings in this Software without prior written       *
 * authorization.                                                           *
 ****************************************************************************/

/****************************************************************************
 *  Author: Zeyd M. Ben-Halim <zmbenhal@netcom.com> 1992,1995               *
 *     and: Eric S. Raymond <esr@snark.thyrsus.com>                         *
 *     and: Thomas E. Dickey, 1996 on                                       *
 ****************************************************************************/

/*
 *	tparm.c
 *
 */

#define entry _ncu_entry
#define ENTRY _ncu_ENTRY

#include <curses.priv.h>

#undef entry
#undef ENTRY

#if HAVE_TSEARCH
#include <search.h>
#endif

#include <ctype.h>
#include <tic.h>

MODULE_ID("$Id: lib_tparm.c,v 1.157 2025/02/15 15:20:16 tom Exp $")

/*
 *	char *
 *	tparm(string, ...)
 *
 *	Substitute the given parameters into the given string by the following
 *	rules (taken from terminfo(5)):
 *
 *	     Cursor addressing and other strings  requiring  parame-
 *	ters in the terminal are described by a parameterized string
 *	capability, with escapes like %x in  it.   For  example,  to
 *	address  the  cursor, the cup capability is given, using two
 *	parameters: the row and column to  address  to.   (Rows  and
 *	columns  are  numbered  from  zero and refer to the physical
 *	screen visible to the user, not to any  unseen  memory.)  If
 *	the terminal has memory relative cursor addressing, that can
 *	be indicated by
 *
 *	     The parameter mechanism uses  a  stack  and  special  %
 *	codes  to manipulate it.  Typically a sequence will push one
 *	of the parameters onto the stack and then print it  in  some
 *	format.  Often more complex operations are necessary.
 *
 *	     The % encodings have the following meanings:
 *
 *	     %%        outputs `%'
 *	     %c        print pop() like %c in printf()
 *	     %s        print pop() like %s in printf()
 *           %[[:]flags][width[.precision]][doxXs]
 *                     as in printf, flags are [-+#] and space
 *                     The ':' is used to avoid making %+ or %-
 *                     patterns (see below).
 *
 *	     %p[1-9]   push ith param
 *	     %P[a-z]   set dynamic variable [a-z] to pop()
 *	     %g[a-z]   get dynamic variable [a-z] and push it
 *	     %P[A-Z]   set static variable [A-Z] to pop()
 *	     %g[A-Z]   get static variable [A-Z] and push it
 *	     %l        push strlen(pop)
 *	     %'c'      push char constant c
 *	     %{nn}     push integer constant nn
 *
 *	     %+ %- %* %/ %m
 *	               arithmetic (%m is mod): push(pop() op pop())
 *	     %& %| %^  bit operations: push(pop() op pop())
 *	     %= %> %<  logical operations: push(pop() op pop())
 *	     %A %O     logical and & or operations for conditionals
 *	     %! %~     unary operations push(op pop())
 *	     %i        add 1 to first two params (for ANSI terminals)
 *
 *	     %? expr %t thenpart %e elsepart %;
 *	               if-then-else, %e elsepart is optional.
 *	               else-if's are possible ala Algol 68:
 *	               %? c1 %t b1 %e c2 %t b2 %e c3 %t b3 %e c4 %t b4 %e b5 %;
 *
 *	For those of the above operators which are binary and not commutative,
 *	the stack works in the usual way, with
 *			%gx %gy %m
 *	resulting in x mod y, not the reverse.
 */

NCURSES_EXPORT_VAR(int) _nc_tparm_err = 0;

#define TPS(var) tps->var
#define popcount _nc_popcount	/* workaround for NetBSD 6.0 defect */

#define get_tparm_state(term) \
	    (term != NULL \
	      ? &(term->tparm_state) \
	      : &(_nc_prescreen.tparm_state))

#define isUPPER(c) ((c) >= 'A' && (c) <= 'Z')
#define isLOWER(c) ((c) >= 'a' && (c) <= 'z')
#define tc_BUMP()  if (level < 0 && number < 2) number++

typedef struct {
    const char *format;		/* format-string can be used as cache-key */
    int tparm_type;		/* bit-set for each string-parameter */
    int num_actual;
    int num_parsed;
    int num_popped;
    TPARM_ARG param[NUM_PARM];
    char *p_is_s[NUM_PARM];
} TPARM_DATA;

#if HAVE_TSEARCH
#define MyCache _nc_globals.cached_tparm
#define MyCount _nc_globals.count_tparm
static int which_tparm;
static TPARM_DATA **delete_tparm;
#endif /* HAVE_TSEARCH */

static char dummy[] = "";	/* avoid const-cast */

#if HAVE_TSEARCH
static int
cmp_format(const void *p, const void *q)
{
    const char *a = *(char *const *) p;
    const char *b = *(char *const *) q;
    return strcmp(a, b);
}
#endif

#if HAVE_TSEARCH
static void
visit_nodes(const void *nodep, VISIT which, int depth)
{
    (void) depth;
    if (which == preorder || which == leaf) {
	delete_tparm[which_tparm] = *(TPARM_DATA **) nodep;
	which_tparm++;
    }
}
#endif

NCURSES_EXPORT(void)
_nc_free_tparm(TERMINAL *termp)
{
    TPARM_STATE *tps = get_tparm_state(termp);
#if HAVE_TSEARCH
    if (MyCount != 0) {
	delete_tparm = typeCalloc(TPARM_DATA *, MyCount);
	if (delete_tparm != NULL) {
	    which_tparm = 0;
	    twalk(MyCache, visit_nodes);
	    for (which_tparm = 0; which_tparm < MyCount; ++which_tparm) {
		TPARM_DATA *ptr = delete_tparm[which_tparm];
		if (ptr != NULL) {
		    tdelete(ptr, &MyCache, cmp_format);
		    free((char *) ptr->format);
		    free(ptr);
		}
	    }
	    which_tparm = 0;
	    twalk(MyCache, visit_nodes);
	    FreeAndNull(delete_tparm);
	}
	MyCount = 0;
	which_tparm = 0;
    }
#endif
    FreeAndNull(TPS(out_buff));
    TPS(out_size) = 0;
    TPS(out_used) = 0;

    FreeAndNull(TPS(fmt_buff));
    TPS(fmt_size) = 0;
}

static int
tparm_error(TPARM_STATE *tps, const char *message)
{
    (void) tps;
    (void) message;
    DEBUG(2, ("%s: %s", message, _nc_visbuf(TPS(tparam_base))));
    return ++_nc_tparm_err;
}

#define get_space(tps, need) \
{ \
    size_t need2get = need + TPS(out_used); \
    if (need2get > TPS(out_size)) { \
	TPS(out_size) = need2get * 2; \
	TYPE_REALLOC(char, TPS(out_size), TPS(out_buff)); \
    } \
}

#if NCURSES_EXPANDED
static NCURSES_INLINE void
  (get_space) (TPARM_STATE *tps, size_t need) {
    get_space(tps, need);
}

#undef get_space
#endif

#define save_text(tps, fmt, s, len) \
{ \
    size_t s_len = (size_t) len + strlen(s) + strlen(fmt); \
    get_space(tps, s_len + 1); \
    _nc_SPRINTF(TPS(out_buff) + TPS(out_used), \
		_nc_SLIMIT(TPS(out_size) - TPS(out_used)) \
		fmt, s); \
    TPS(out_used) += strlen(TPS(out_buff) + TPS(out_used)); \
}

#if NCURSES_EXPANDED
static NCURSES_INLINE void
  (save_text) (TPARM_STATE *tps, const char *fmt, const char *s, int len) {
    save_text(tps, fmt, s, len);
}

#undef save_text
#endif

#define save_number(tps, fmt, number, len) \
{ \
    size_t s_len = (size_t) len + 30 + strlen(fmt); \
    get_space(tps, s_len + 1); \
    _nc_SPRINTF(TPS(out_buff) + TPS(out_used), \
		_nc_SLIMIT(TPS(out_size) - TPS(out_used)) \
		fmt, number); \
    TPS(out_used) += strlen(TPS(out_buff) + TPS(out_used)); \
}

#if NCURSES_EXPANDED
static NCURSES_INLINE void
  (save_number) (TPARM_STATE *tps, const char *fmt, int number, int len) {
    save_number(tps, fmt, number, len);
}

#undef save_number
#endif

#define save_char(tps, c) \
{ \
    get_space(tps, (size_t) 1); \
    TPS(out_buff)[TPS(out_used)++] = (char) ((c == 0) ? 0200 : c); \
}

#if NCURSES_EXPANDED
static NCURSES_INLINE void
  (save_char) (TPARM_STATE *tps, int c) {
    save_char(tps, c);
}

#undef save_char
#endif

#define npush(tps, x) \
{ \
    if (TPS(stack_ptr) < STACKSIZE) { \
	TPS(stack)[TPS(stack_ptr)].num_type = TRUE; \
	TPS(stack)[TPS(stack_ptr)].data.num = x; \
	TPS(stack_ptr)++; \
    } else { \
	(void) tparm_error(tps, "npush: stack overflow"); \
    } \
}

#if NCURSES_EXPANDED
static NCURSES_INLINE void
  (npush) (TPARM_STATE *tps, int x) {
    npush(tps, x);
}

#undef npush
#endif

#define spush(tps, x) \
{ \
    if (TPS(stack_ptr) < STACKSIZE) { \
	TPS(stack)[TPS(stack_ptr)].num_type = FALSE; \
	TPS(stack)[TPS(stack_ptr)].data.str = x; \
	TPS(stack_ptr)++; \
    } else { \
	(void) tparm_error(tps, "spush: stack overflow"); \
    } \
}

#if NCURSES_EXPANDED
static NCURSES_INLINE void
  (spush) (TPARM_STATE *tps, char *x) {
    spush(tps, x);
}

#undef spush
#endif

#define npop(tps) \
    ((TPS(stack_ptr)-- > 0) \
     ? ((TPS(stack)[TPS(stack_ptr)].num_type) \
	 ? TPS(stack)[TPS(stack_ptr)].data.num \
	 : 0) \
     : (tparm_error(tps, "npop: stack underflow"), \
        TPS(stack_ptr) = 0))

#if NCURSES_EXPANDED
static NCURSES_INLINE int
  (npop) (TPARM_STATE *tps) {
    return npop(tps);
}
#undef npop
#endif

#define spop(tps) \
    ((TPS(stack_ptr)-- > 0) \
     ? ((!TPS(stack)[TPS(stack_ptr)].num_type \
        && TPS(stack)[TPS(stack_ptr)].data.str != NULL) \
         ? TPS(stack)[TPS(stack_ptr)].data.str \
         : dummy) \
     : (tparm_error(tps, "spop: stack underflow"), \
        dummy))

#if NCURSES_EXPANDED
static NCURSES_INLINE char *
  (spop) (TPARM_STATE *tps) {
    return spop(tps);
}
#undef spop
#endif

static NCURSES_INLINE const char *
parse_format(const char *s, char *format, int *len)
{
    *len = 0;
    if (format != NULL) {
	bool done = FALSE;
	bool allowminus = FALSE;
	bool dot = FALSE;
	bool err = FALSE;
	char *fmt = format;
	int my_width = 0;
	int my_prec = 0;
	int value = 0;

	*len = 0;
	*format++ = '%';
	while (*s != '\0' && !done) {
	    switch (*s) {
	    case 'c':		/* FALLTHRU */
	    case 'd':		/* FALLTHRU */
	    case 'o':		/* FALLTHRU */
	    case 'x':		/* FALLTHRU */
	    case 'X':		/* FALLTHRU */
	    case 's':
#ifdef EXP_XTERM_1005
	    case 'u':
#endif
		*format++ = *s;
		done = TRUE;
		break;
	    case '.':
		*format++ = *s++;
		if (dot) {
		    err = TRUE;
		} else {	/* value before '.' is the width */
		    dot = TRUE;
		    my_width = value;
		}
		value = 0;
		break;
	    case '#':
		*format++ = *s++;
		break;
	    case ' ':
		*format++ = *s++;
		break;
	    case ':':
		s++;
		allowminus = TRUE;
		break;
	    case '-':
		if (allowminus) {
		    *format++ = *s++;
		} else {
		    done = TRUE;
		}
		break;
	    default:
		if (isdigit(UChar(*s))) {
		    value = (value * 10) + (*s - '0');
		    if (value > 10000)
			err = TRUE;
		    *format++ = *s++;
		} else {
		    done = TRUE;
		}
	    }
	}

	/*
	 * If we found an error, ignore (and remove) the flags.
	 */
	if (err) {
	    my_width = my_prec = value = 0;
	    format = fmt;
	    *format++ = '%';
	    *format++ = *s;
	}

	/*
	 * Any value after '.' is the precision.  If we did not see '.', then
	 * the value is the width.
	 */
	if (dot)
	    my_prec = value;
	else
	    my_width = value;

	*format = '\0';
	/* return maximum string length in print */
	*len = (my_width > my_prec) ? my_width : my_prec;
    }
    return s;
}

/*
 * Analyze the string to see how many parameters we need from the varargs list,
 * and what their types are.  We will only accept string parameters if they
 * appear as a %l or %s format following an explicit parameter reference (e.g.,
 * %p2%s).  All other parameters are numbers.
 *
 * 'number' counts coarsely the number of pop's we see in the string, and
 * 'popcount' shows the highest parameter number in the string.  We would like
 * to simply use the latter count, but if we are reading termcap strings, there
 * may be cases that we cannot see the explicit parameter numbers.
 */
NCURSES_EXPORT(int)
_nc_tparm_analyze(TERMINAL *term, const char *string, char **p_is_s, int *popcount)
{
    TPARM_STATE *tps = get_tparm_state(term);
    size_t len2;
    int i;
    int lastpop = -1;
    int len;
    int number = 0;
    int level = -1;
    const char *cp = string;

    if (cp == NULL)
	return 0;

    if ((len2 = strlen(cp)) + 2 > TPS(fmt_size)) {
	TPS(fmt_size) += len2 + 2;
	TPS(fmt_buff) = typeRealloc(char, TPS(fmt_size), TPS(fmt_buff));
	if (TPS(fmt_buff) == NULL)
	    return 0;
    }

    memset(p_is_s, 0, sizeof(p_is_s[0]) * NUM_PARM);
    *popcount = 0;

    while ((cp - string) < (int) len2) {
	if (*cp == '%') {
	    cp++;
	    cp = parse_format(cp, TPS(fmt_buff), &len);
	    switch (*cp) {
	    default:
		break;

	    case 'd':		/* FALLTHRU */
	    case 'o':		/* FALLTHRU */
	    case 'x':		/* FALLTHRU */
	    case 'X':		/* FALLTHRU */
	    case 'c':		/* FALLTHRU */
#ifdef EXP_XTERM_1005
	    case 'u':
#endif
		if (lastpop <= 0) {
		    tc_BUMP();
		}
		level -= 1;
		lastpop = -1;
		break;

	    case 'l':
	    case 's':
		if (lastpop > 0) {
		    level -= 1;
		    p_is_s[lastpop - 1] = dummy;
		}
		tc_BUMP();
		break;

	    case 'p':
		cp++;
		i = (UChar(*cp) - '0');
		if (i >= 0 && i <= NUM_PARM) {
		    ++level;
		    lastpop = i;
		    if (lastpop > *popcount)
			*popcount = lastpop;
		}
		break;

	    case 'P':
		++cp;
		break;

	    case 'g':
		++level;
		cp++;
		break;

	    case S_QUOTE:
		++level;
		cp += 2;
		lastpop = -1;
		break;

	    case L_BRACE:
		++level;
		cp++;
		while (isdigit(UChar(*cp))) {
		    cp++;
		}
		break;

	    case '+':
	    case '-':
	    case '*':
	    case '/':
	    case 'm':
	    case 'A':
	    case 'O':
	    case '&':
	    case '|':
	    case '^':
	    case '=':
	    case '<':
	    case '>':
		tc_BUMP();
		level -= 1;	/* pop 2, operate, push 1 */
		lastpop = -1;
		break;

	    case '!':
	    case '~':
		tc_BUMP();
		lastpop = -1;
		break;

	    case 'i':
		/* will add 1 to first (usually two) parameters */
		break;
	    }
	}
	if (*cp != '\0')
	    cp++;
    }

    if (number > NUM_PARM)
	number = NUM_PARM;
    return number;
}

/*
 * Analyze the capability string, finding the number of parameters and their
 * types.
 *
 * TODO: cache the result so that this is done once per capability per term.
 */
static int
tparm_setup(TERMINAL *term, const char *string, TPARM_DATA *result)
{
    TPARM_STATE *tps = get_tparm_state(term);
    int rc = OK;

    TPS(out_used) = 0;
    memset(result, 0, sizeof(*result));

    if (!VALID_STRING(string)) {
	TR(TRACE_CALLS, ("%s: format is invalid", TPS(tname)));
	rc = ERR;
    } else {
#if HAVE_TSEARCH
	TPARM_DATA *fs;
	void *ft;

	result->format = string;
	if ((ft = tfind(result, &MyCache, cmp_format)) != NULL) {
	    size_t len2;
	    fs = *(TPARM_DATA **) ft;
	    *result = *fs;
	    if ((len2 = strlen(string)) + 2 > TPS(fmt_size)) {
		TPS(fmt_size) += len2 + 2;
		TPS(fmt_buff) = typeRealloc(char, TPS(fmt_size), TPS(fmt_buff));
		if (TPS(fmt_buff) == NULL)
		    return ERR;
	    }
	} else
#endif
	{
	    /*
	     * Find the highest parameter-number referred to in the format
	     * string.  Use this value to limit the number of arguments copied
	     * from the variable-length argument list.
	     */
	    result->num_parsed = _nc_tparm_analyze(term, string,
						   result->p_is_s,
						   &(result->num_popped));
	    if (TPS(fmt_buff) == NULL) {
		TR(TRACE_CALLS, ("%s: error in analysis", TPS(tname)));
		rc = ERR;
	    } else {
		int n;

		if (result->num_parsed > NUM_PARM)
		    result->num_parsed = NUM_PARM;
		if (result->num_popped > NUM_PARM)
		    result->num_popped = NUM_PARM;
		result->num_actual = Max(result->num_popped, result->num_parsed);

		for (n = 0; n < result->num_actual; ++n) {
		    if (result->p_is_s[n])
			result->tparm_type |= (1 << n);
		}
#if HAVE_TSEARCH
		if ((fs = typeCalloc(TPARM_DATA, 1)) != NULL) {
		    *fs = *result;
		    if ((fs->format = strdup(string)) != NULL) {
			if (tsearch(fs, &MyCache, cmp_format) != NULL) {
			    ++MyCount;
			} else {
			    free(fs);
			    rc = ERR;
			}
		    } else {
			free(fs);
			rc = ERR;
		    }
		} else {
		    rc = ERR;
		}
#endif
	    }
	}
    }

    return rc;
}

/*
 * A few caps (such as plab_norm) have string-valued parms.  We'll have to
 * assume that the caller knows the difference, since a char* and an int may
 * not be the same size on the stack.  The normal prototype for tparm uses 9
 * long's, which is consistent with our va_arg() usage.
 */
static void
tparm_copy_valist(TPARM_DATA *data, int use_TPARM_ARG, va_list ap)
{
    int i;

    for (i = 0; i < data->num_actual; i++) {
	if (data->p_is_s[i] != NULL) {
	    char *value = va_arg(ap, char *);
	    if (value == NULL)
		value = dummy;
	    data->p_is_s[i] = value;
	    data->param[i] = 0;
	} else if (use_TPARM_ARG) {
	    data->param[i] = va_arg(ap, TPARM_ARG);
	} else {
	    data->param[i] = (TPARM_ARG) va_arg(ap, int);
	}
    }
}

/*
 * This is a termcap compatibility hack.  If there are no explicit pop
 * operations in the string, load the stack in such a way that successive pops
 * will grab successive parameters.  That will make the expansion of (for
 * example) \E[%d;%dH work correctly in termcap style, which means tparam()
 * will expand termcap strings OK.
 */
static bool
tparm_tc_compat(TPARM_STATE *tps, TPARM_DATA *data)
{
    bool termcap_hack = FALSE;

    TPS(stack_ptr) = 0;

    if (data->num_popped == 0) {
	int i;

	termcap_hack = TRUE;
	for (i = data->num_parsed - 1; i >= 0; i--) {
	    if (data->p_is_s[i]) {
		spush(tps, data->p_is_s[i]);
	    } else {
		npush(tps, (int) data->param[i]);
	    }
	}
    }
    return termcap_hack;
}

#ifdef TRACE
static void
tparm_trace_call(TPARM_STATE *tps, const char *string, TPARM_DATA *data)
{
    if (USE_TRACEF(TRACE_CALLS)) {
	int i;
	for (i = 0; i < data->num_actual; i++) {
	    if (data->p_is_s[i] != NULL) {
		save_text(tps, ", %s", _nc_visbuf(data->p_is_s[i]), 0);
	    } else if ((long) data->param[i] > MAX_OF_TYPE(NCURSES_INT2) ||
		       (long) data->param[i] < 0) {
		_tracef("BUG: problem with tparm parameter #%d of %d",
			i + 1, data->num_actual);
		break;
	    } else {
		save_number(tps, ", %d", (int) data->param[i], 0);
	    }
	}
	_tracef(T_CALLED("%s(%s%s)"), TPS(tname), _nc_visbuf(string), TPS(out_buff));
	TPS(out_used) = 0;
	_nc_unlock_global(tracef);
    }
}

#else
#define tparm_trace_call(tps, string, data)	/* nothing */
#endif /* TRACE */

#define init_vars(name) \
	if (!name##_used) { \
	    name##_used = TRUE; \
	    memset(name##_vars, 0, sizeof(name##_vars)); \
	}

static NCURSES_INLINE char *
tparam_internal(TPARM_STATE *tps, const char *string, TPARM_DATA *data)
{
    int number;
    int len;
    int level;
    int x, y;
    int i;
    const char *s;
    const char *cp = string;
    size_t len2 = strlen(cp);
    bool incremented_two = FALSE;
    bool termcap_hack = tparm_tc_compat(tps, data);
    /*
     * SVr4 curses stores variables 'A' to 'Z' in the TERMINAL structure (so
     * they are initialized once to zero), and variables 'a' to 'z' on the
     * stack in tparm, referring to the former as "static" and the latter as
     * "dynamic".  However, it makes no check to ensure that the "dynamic"
     * variables are initialized.
     *
     * Solaris xpg4 curses makes no distinction between the upper/lower, and
     * stores the common set of 26 variables on the stack, without initializing
     * them.
     *
     * In ncurses, both sets of variables are initialized on the first use.
     */
    bool dynamic_used = FALSE;
    int dynamic_vars[NUM_VARS];

    tparm_trace_call(tps, string, data);

    if (TPS(fmt_buff) == NULL) {
	T((T_RETURN("<null>")));
	return NULL;
    }

    while ((cp - string) < (int) len2) {
	if (*cp != '%') {
	    save_char(tps, UChar(*cp));
	} else {
	    TPS(tparam_base) = cp++;
	    cp = parse_format(cp, TPS(fmt_buff), &len);
	    switch (*cp) {
	    default:
		break;
	    case '%':
		save_char(tps, '%');
		break;

	    case 'd':		/* FALLTHRU */
	    case 'o':		/* FALLTHRU */
	    case 'x':		/* FALLTHRU */
	    case 'X':		/* FALLTHRU */
		x = npop(tps);
		save_number(tps, TPS(fmt_buff), x, len);
		break;

	    case 'c':		/* FALLTHRU */
		x = npop(tps);
		save_char(tps, x);
		break;

#ifdef EXP_XTERM_1005
	    case 'u':
		{
		    unsigned char target[10];
		    unsigned source = (unsigned) npop(tps);
		    int rc = _nc_conv_to_utf8(target, source, (unsigned)
					      sizeof(target));
		    int n;
		    for (n = 0; n < rc; ++n) {
			save_char(tps, target[n]);
		    }
		}
		break;
#endif
	    case 'l':
		s = spop(tps);
		npush(tps, (int) strlen(s));
		break;

	    case 's':
		s = spop(tps);
		save_text(tps, TPS(fmt_buff), s, len);
		break;

	    case 'p':
		cp++;
		i = (UChar(*cp) - '1');
		if (i >= 0 && i < NUM_PARM) {
		    if (data->p_is_s[i]) {
			spush(tps, data->p_is_s[i]);
		    } else {
			npush(tps, (int) data->param[i]);
		    }
		}
		break;

	    case 'P':
		cp++;
		if (isUPPER(*cp)) {
		    i = (UChar(*cp) - 'A');
		    TPS(static_vars)[i] = npop(tps);
		} else if (isLOWER(*cp)) {
		    i = (UChar(*cp) - 'a');
		    init_vars(dynamic);
		    dynamic_vars[i] = npop(tps);
		}
		break;

	    case 'g':
		cp++;
		if (isUPPER(*cp)) {
		    i = (UChar(*cp) - 'A');
		    npush(tps, TPS(static_vars)[i]);
		} else if (isLOWER(*cp)) {
		    i = (UChar(*cp) - 'a');
		    init_vars(dynamic);
		    npush(tps, dynamic_vars[i]);
		}
		break;

	    case S_QUOTE:
		cp++;
		npush(tps, UChar(*cp));
		cp++;
		break;

	    case L_BRACE:
		number = 0;
		cp++;
		while (isdigit(UChar(*cp))) {
		    number = (number * 10) + (UChar(*cp) - '0');
		    cp++;
		}
		npush(tps, number);
		break;

	    case '+':
		y = npop(tps);
		x = npop(tps);
		npush(tps, x + y);
		break;

	    case '-':
		y = npop(tps);
		x = npop(tps);
		npush(tps, x - y);
		break;

	    case '*':
		y = npop(tps);
		x = npop(tps);
		npush(tps, x * y);
		break;

	    case '/':
		y = npop(tps);
		x = npop(tps);
		npush(tps, y ? (x / y) : 0);
		break;

	    case 'm':
		y = npop(tps);
		x = npop(tps);
		npush(tps, y ? (x % y) : 0);
		break;

	    case 'A':
		y = npop(tps);
		x = npop(tps);
		npush(tps, y && x);
		break;

	    case 'O':
		y = npop(tps);
		x = npop(tps);
		npush(tps, y || x);
		break;

	    case '&':
		y = npop(tps);
		x = npop(tps);
		npush(tps, x & y);
		break;

	    case '|':
		y = npop(tps);
		x = npop(tps);
		npush(tps, x | y);
		break;

	    case '^':
		y = npop(tps);
		x = npop(tps);
		npush(tps, x ^ y);
		break;

	    case '=':
		y = npop(tps);
		x = npop(tps);
		npush(tps, x == y);
		break;

	    case '<':
		y = npop(tps);
		x = npop(tps);
		npush(tps, x < y);
		break;

	    case '>':
		y = npop(tps);
		x = npop(tps);
		npush(tps, x > y);
		break;

	    case '!':
		x = npop(tps);
		npush(tps, !x);
		break;

	    case '~':
		x = npop(tps);
		npush(tps, ~x);
		break;

	    case 'i':
		/*
		 * Increment the first two parameters -- if they are numbers
		 * rather than strings.  As a side effect, assign into the
		 * stack; if this is termcap, then the stack was populated
		 * using the termcap hack above rather than via the terminfo
		 * 'p' case.
		 */
		if (!incremented_two) {
		    incremented_two = TRUE;
		    if (data->p_is_s[0] == NULL) {
			data->param[0]++;
			if (termcap_hack)
			    TPS(stack)[0].data.num = (int) data->param[0];
		    }
		    if (data->p_is_s[1] == NULL) {
			data->param[1]++;
			if (termcap_hack)
			    TPS(stack)[1].data.num = (int) data->param[1];
		    }
		}
		break;

	    case '?':
		break;

	    case 't':
		x = npop(tps);
		if (!x) {
		    /* scan forward for %e or %; at level zero */
		    cp++;
		    level = 0;
		    while (*cp) {
			if (*cp == '%') {
			    cp++;
			    if (*cp == '?')
				level++;
			    else if (*cp == ';') {
				if (level > 0)
				    level--;
				else
				    break;
			    } else if (*cp == 'e' && level == 0)
				break;
			}

			if (*cp)
			    cp++;
		    }
		}
		break;

	    case 'e':
		/* scan forward for a %; at level zero */
		cp++;
		level = 0;
		while (*cp) {
		    if (*cp == '%') {
			cp++;
			if (*cp == '?')
			    level++;
			else if (*cp == ';') {
			    if (level > 0)
				level--;
			    else
				break;
			}
		    }

		    if (*cp)
			cp++;
		}
		break;

	    case ';':
		break;

	    }			/* endswitch (*cp) */
	}			/* endelse (*cp == '%') */

	if (*cp == '\0')
	    break;

	cp++;
    }				/* endwhile (*cp) */

    get_space(tps, (size_t) 1);
    TPS(out_buff)[TPS(out_used)] = '\0';

    if (TPS(stack_ptr) && !_nc_tparm_err) {
	DEBUG(2, ("tparm: stack has %d item%s on return",
		  TPS(stack_ptr),
		  TPS(stack_ptr) == 1 ? "" : "s"));
	_nc_tparm_err++;
    }

    T((T_RETURN("%s"), _nc_visbuf(TPS(out_buff))));
    return (TPS(out_buff));
}

#ifdef CUR
/*
 * Only a few standard capabilities accept string parameters.  The others that
 * are parameterized accept only numeric parameters.
 */
static bool
check_string_caps(const TPARM_DATA *data, const char *string)
{
    bool result = FALSE;

#define CHECK_CAP(name) (VALID_STRING(name) && !strcmp(name, string))

    /*
     * Disallow string parameters unless we can check them against a terminal
     * description.
     */
    if (cur_term != NULL) {
	int want_type = 0;

	if (CHECK_CAP(pkey_key))
	    want_type = 2;	/* function key #1, type string #2 */
	else if (CHECK_CAP(pkey_local))
	    want_type = 2;	/* function key #1, execute string #2 */
	else if (CHECK_CAP(pkey_xmit))
	    want_type = 2;	/* function key #1, transmit string #2 */
	else if (CHECK_CAP(plab_norm))
	    want_type = 2;	/* label #1, show string #2 */
#ifdef pkey_plab
	else if (CHECK_CAP(pkey_plab))
	    want_type = 6;	/* function key #1, type string #2, show string #3 */
#endif
#if NCURSES_XNAMES
	else {
	    const char *check;

	    check = tigetstr(UserCap(Cs));
	    if (CHECK_CAP(check))
		want_type = 1;	/* style #1 */

	    check = tigetstr(UserCap(Ms));
	    if (CHECK_CAP(check))
		want_type = 3;	/* storage unit #1, content #2 */
	}
#endif

	if (want_type == data->tparm_type) {
	    result = TRUE;
	} else {
	    T(("unexpected string-parameter"));
	}
    }
    return result;
}

#define ValidCap(allow_strings) (myData.tparm_type == 0 || \
				 (allow_strings && \
				  check_string_caps(&myData, string)))
#else
#define ValidCap(allow_strings) 1
#endif

#if NCURSES_TPARM_VARARGS

NCURSES_EXPORT(char *)
tparm(const char *string, ...)
{
    TPARM_STATE *tps = get_tparm_state(cur_term);
    TPARM_DATA myData;
    char *result = NULL;

    _nc_tparm_err = 0;
#ifdef TRACE
    tps->tname = "tparm";
#endif /* TRACE */

    if (tparm_setup(cur_term, string, &myData) == OK && ValidCap(TRUE)) {
	va_list ap;

	va_start(ap, string);
	tparm_copy_valist(&myData, TRUE, ap);
	va_end(ap);

	result = tparam_internal(tps, string, &myData);
    }
    return result;
}

#else /* !NCURSES_TPARM_VARARGS */

NCURSES_EXPORT(char *)
tparm(const char *string,
      TPARM_ARG a1,
      TPARM_ARG a2,
      TPARM_ARG a3,
      TPARM_ARG a4,
      TPARM_ARG a5,
      TPARM_ARG a6,
      TPARM_ARG a7,
      TPARM_ARG a8,
      TPARM_ARG a9)
{
    TPARM_STATE *tps = get_tparm_state(cur_term);
    TPARM_DATA myData;
    char *result = NULL;

    _nc_tparm_err = 0;
#ifdef TRACE
    tps->tname = "tparm";
#endif /* TRACE */

#define string_ok (sizeof(char*) <= sizeof(TPARM_ARG))

    if (tparm_setup(cur_term, string, &myData) == OK && ValidCap(string_ok)) {

	myData.param[0] = a1;
	myData.param[1] = a2;
	myData.param[2] = a3;
	myData.param[3] = a4;
	myData.param[4] = a5;
	myData.param[5] = a6;
	myData.param[6] = a7;
	myData.param[7] = a8;
	myData.param[8] = a9;

	result = tparam_internal(tps, string, &myData);
    }
    return result;
}

#endif /* NCURSES_TPARM_VARARGS */

NCURSES_EXPORT(char *)
tiparm(const char *string, ...)
{
    TPARM_STATE *tps = get_tparm_state(cur_term);
    TPARM_DATA myData;
    char *result = NULL;

    _nc_tparm_err = 0;
#ifdef TRACE
    tps->tname = "tiparm";
#endif /* TRACE */

    if (tparm_setup(cur_term, string, &myData) == OK && ValidCap(TRUE)) {
	va_list ap;

	va_start(ap, string);
	tparm_copy_valist(&myData, FALSE, ap);
	va_end(ap);

	result = tparam_internal(tps, string, &myData);
    }
    return result;
}

/*
 * Use tparm if the formatting string matches the expected number of parameters
 * counting string-parameters.
 */
NCURSES_EXPORT(char *)
tiparm_s(int num_expected, int tparm_type, const char *string, ...)
{
    TPARM_STATE *tps = get_tparm_state(cur_term);
    TPARM_DATA myData;
    char *result = NULL;

    _nc_tparm_err = 0;
#ifdef TRACE
    tps->tname = "tiparm_s";
#endif /* TRACE */
    if (num_expected >= 0 &&
	num_expected <= 9 &&
	tparm_type >= 0 &&
	tparm_type < 7 &&	/* limit to 2 string parameters */
	tparm_setup(cur_term, string, &myData) == OK &&
	myData.tparm_type == tparm_type &&
	myData.num_actual == num_expected) {
	va_list ap;

	va_start(ap, string);
	tparm_copy_valist(&myData, FALSE, ap);
	va_end(ap);

	result = tparam_internal(tps, string, &myData);
    }
    return result;
}

/*
 * Analyze the formatting string, return the analysis.
 */
NCURSES_EXPORT(int)
tiscan_s(int *num_expected, int *tparm_type, const char *string)
{
    TPARM_DATA myData;
    int result = ERR;

#ifdef TRACE
    TPARM_STATE *tps = get_tparm_state(cur_term);
    tps->tname = "tiscan_s";
#endif /* TRACE */

    if (tparm_setup(cur_term, string, &myData) == OK) {
	*num_expected = myData.num_actual;
	*tparm_type = myData.tparm_type;
	result = OK;
    }
    return result;
}

/*
 * The internal-use flavor ensures that parameters are numbers, not strings.
 * In addition to ensuring that they are numbers, it ensures that the parameter
 * count is consistent with intended usage.
 *
 * Unlike the general-purpose tparm/tiparm, these internal calls are fairly
 * well defined:
 *
 * expected == 0 - not applicable
 * expected == 1 - set color, or vertical/horizontal addressing
 * expected == 2 - cursor addressing
 * expected == 4 - initialize color or color pair
 * expected == 9 - set attributes
 *
 * Only for the last case (set attributes) should a parameter be optional.
 * Also, a capability which calls for more parameters than expected should be
 * ignored.
 *
 * Return a null if the parameter-checks fail.  Otherwise, return a pointer to
 * the formatted capability string.
 */
NCURSES_EXPORT(char *)
_nc_tiparm(int expected, const char *string, ...)
{
    TPARM_STATE *tps = get_tparm_state(cur_term);
    TPARM_DATA myData;
    char *result = NULL;

    _nc_tparm_err = 0;
    T((T_CALLED("_nc_tiparm(%d, %s, ...)"), expected, _nc_visbuf(string)));
#ifdef TRACE
    tps->tname = "_nc_tiparm";
#endif /* TRACE */

    if (tparm_setup(cur_term, string, &myData) == OK && ValidCap(FALSE)) {
#ifdef CUR
	if (myData.num_actual != expected && cur_term != NULL) {
	    int needed = expected;
	    if (CHECK_CAP(to_status_line)) {
		needed = 0;	/* allow for xterm's status line */
	    } else if (CHECK_CAP(set_a_background)) {
		needed = 0;	/* allow for monochrome fakers */
	    } else if (CHECK_CAP(set_a_foreground)) {
		needed = 0;
	    } else if (CHECK_CAP(set_background)) {
		needed = 0;
	    } else if (CHECK_CAP(set_foreground)) {
		needed = 0;
	    }
#if NCURSES_XNAMES
	    else {
		const char *check;

		check = tigetstr(UserCap(xm));
		if (CHECK_CAP(check)) {
		    needed = 3;
		}
		check = tigetstr(UserCap(S0));
		if (CHECK_CAP(check)) {
		    needed = 0;	/* used in screen-base */
		}
	    }
#endif
	    if (myData.num_actual >= needed && myData.num_actual <= expected)
		expected = myData.num_actual;
	}
#endif
	if (myData.num_actual == 0 && expected) {
	    T(("missing parameter%s, expected %s%d",
	       expected > 1 ? "s" : "",
	       expected == 9 ? "up to " : "",
	       expected));
	} else if (myData.num_actual > expected) {
	    T(("too many parameters, have %d, expected %d",
	       myData.num_actual,
	       expected));
	} else if (expected != 9 && myData.num_actual != expected) {
	    T(("expected %d parameters, have %d",
	       myData.num_actual,
	       expected));
	} else {
	    va_list ap;

	    va_start(ap, string);
	    tparm_copy_valist(&myData, FALSE, ap);
	    va_end(ap);

	    result = tparam_internal(tps, string, &myData);
	}
    }
    returnPtr(result);
}

/*
 * Improve tic's checks by resetting the terminfo "static variables" before
 * calling functions which may update them.
 */
NCURSES_EXPORT(void)
_nc_reset_tparm(TERMINAL *term)
{
    TPARM_STATE *tps = get_tparm_state(term);
    memset(TPS(static_vars), 0, sizeof(TPS(static_vars)));
}
