/*	EVAL.C:	Expression evaluation functions for
		MicroEMACS

	written 1986 by Daniel Lawrence
 *
 * $Header: /usr/build/vile/vile/RCS/eval.c,v 1.168 1998/09/22 23:02:21 tom Exp $
 *
 */

#include	"estruct.h"
#include	"edef.h"
#include	"nevars.h"
#include	"patchlev.h"

#define	FUNC_NAMELEN	4

#define	ILLEGAL_NUM	-1
#define	MODE_NUM	-2
#define	USER_NUM	-3

#if SYS_OS2 || SYS_OS2_EMX
#  define SHELL_NAME "COMSPEC"
#  define SHELL_PATH "cmd.exe"
#else
#  if SYS_WINNT
#    define SHELL_NAME "COMSPEC"
#    define SHELL_PATH (is_winnt() ? "cmd.exe" : "command.com")
#  else
#    if SYS_MSDOS
#      define SHELL_NAME "COMSPEC"
#      define SHELL_PATH "command.com"
#    else
#      define SHELL_NAME "SHELL"
#      define SHELL_PATH "/bin/sh"
#    endif
#  endif
#endif

/* When the command interpretor needs to get a variable's name, rather than its
 * value, it is passed back as a VDESC variable description structure.  The
 * v_num field is an index into the appropriate variable table.
 */

	/* macros for environment-variable switch */
	/*  (if your compiler balks with "non-constant case expression" */
#if CC_CANNOT_OFFSET_CASES
#define	If(N)		if (vnum == N) {
#define	ElseIf(N)	} else If(N)
#define	Otherwise	} else {
#define	EndIf		}
#else			/* more compact if it works... */
#define	If(N)		switch (vnum) { case N: {
#define	ElseIf(N)	break; } case N: {
#define	Otherwise	break; } default: {
#define	EndIf		}}
#endif

#if OPT_EVAL
typedef struct	{
	int	v_type;	/* type of variable */
	int	v_num;	/* index, if it's an environment-variable */
	UVAR *	v_ptr;	/* pointer, if it's a user-variable */
	} VDESC;

static	SIZE_T	s2size ( char *s );
static	char *	getkill (void);
static	char *	ltos ( int val );
static	char *	s2offset ( char *s, char *n );
static	int	PromptAndSet ( const char *var, int f, int n );
static	int	SetVarValue ( VDESC *var, const char *value );
static	int	ernd (void);
static	int	gtlbl ( const char *tokn );
static	int	l_strtol ( const char *s );
static	int	sindex ( const char *sourc, const char *pattern );
#endif

/*--------------------------------------------------------------------------*/

#if	ENVFUNC && OPT_EVAL
static char *
GetEnv(char *s)
{
	register char *v = getenv(s);
	return v ? v : "";
}

static char *
DftEnv(
register char	*name,
register char	*dft)
{
	name = GetEnv(name);
	return (*name == EOS) ? dft : name;
}

static void
SetEnv(
char	**namep,
const char *value)
{
	FreeIfNeeded(*namep);
	*namep = strmalloc(value);
}
#else
#define	GetEnv(s)	""
#define	DftEnv(s,d)	d
#define	SetEnv(np,s)	(*(np) = strmalloc(s))
#endif

#if OPT_EVAL && OPT_SHELL
static char *shell;	/* $SHELL environment is "$shell" variable */
static char *directory;	/* $TMP environment is "$directory" variable */
#if DISP_X11
static char *x_display;	/* $DISPLAY environment is "$xdisplay" variable */
static char *x_shell;	/* $XSHELL environment is "$xshell" variable */
#endif
#endif

#if OPT_EVAL && OPT_SHELL
char *
get_shell(void)
{
	if (shell == 0)
		SetEnv(&shell, DftEnv(SHELL_NAME, SHELL_PATH));
	return shell;
}
#endif

#if OPT_SHOW_EVAL
/* list the current vars into the current buffer */
/* ARGSUSED */
static void
makevarslist(int dum1 GCC_UNUSED, void *ptr)
{
	register UVAR *p;
	register int j;

	bprintf("--- Environment variables %*P\n", term.t_ncol-1, '-');
	bprintf("%s", (char *)ptr);
	for (p = user_vars, j = 0; p != 0; p = p->next) {
		if (!j++)
			bprintf("--- User variables %*P", term.t_ncol-1, '-');
		bprintf("\n%%%s = %s", p->u_name, p->u_value);
	}
}

/* Test a name to ensure that it is a mode-name, filtering out modish-stuff
 * such as "all" and "noview"
 */
static int
is_mode_name(const char *name, int showall, VALARGS *args)
{
	if (is_varmode(name)) {
		if (find_mode(name, -TRUE, args)) {
			if (!showall && !strcmp(name, args->names->shortname))
				return FALSE;
			return TRUE;
		}
		return SORTOFTRUE;
	}
	return FALSE;
}

/* filter out mode-names that apply only to abbreviations */
static const char *
get_listvalue(const char *name, int showall)
{
	VALARGS args;
	register int	s;

	if ((s = is_mode_name(name, showall, &args)) == TRUE)
		return string_mode_val(&args);
	else if (s == SORTOFTRUE)
		return gtenv(name);
	return 0;
}
#endif /* OPT_SHOW_EVAL */

/* ARGSUSED */
#if OPT_SHOW_EVAL
int
listvars(int f, int n)
{
	char *values;
	register WINDOW *wp = curwp;
	register int s;
	register ALLOC_T t;
	register char *v;
	register const char *vv;
	static	const char fmt[] = { "$%s = %*S\n" };
	const char *const *Names = f ? list_of_modes() : envars;
	int	showall = f ? (n > 1) : FALSE;

	/* collect data for environment-variables, since some depend on window */
	for (s = t = 0; Names[s] != 0; s++) {
		if ((vv = get_listvalue(Names[s], showall)) != 0)
			t += strlen(Names[s]) + strlen(fmt) + strlen(vv);
	}
	if ((values = typeallocn(char, t)) == 0)
		return FALSE;

	for (s = 0, v = values; Names[s] != 0; s++) {
		if ((vv = get_listvalue(Names[s], showall)) != 0) {
			t = strlen(vv);
			if (t == 0) {
				t = 1;
				vv = "";
			} else if (vv[t-1] == '\n')
				t--;	/* suppress trailing newline */
			v = lsprintf(v, fmt, Names[s], t, vv);
		}
	}
	s = liststuff(VARIABLES_BufName, FALSE,
				makevarslist, 0, (void *)values);
	free(values);

	/* back to the buffer whose modes we just listed */
	swbuffer(wp->w_bufp);
	return s;
}
#endif /* OPT_SHOW_EVAL */

#if OPT_EVAL
static const char *
gtfun(			/* evaluate a function */
const char *fname)	/* name of function to evaluate */
{
	register int fnum;		/* index to function to eval */
	const char *it = errorm;
	char arg0[FUNC_NAMELEN];
	char arg1[NSTRING];		/* value of first argument */
	char arg2[NSTRING];		/* value of second argument */
	char arg3[NSTRING];		/* value of third argument */
	static char result[2 * NSTRING];	/* string result */

	*arg1 = *arg2 = *arg3 = EOS;
	if (!fname[0])
		return(it);

	/* look the function up in the function table */
	mklower(strncpy0(arg0, fname, FUNC_NAMELEN)); /* case-independent */
	for (fnum = 0; fnum < NFUNCS; fnum++)
		if (strcmp(arg0, funcs[fnum].f_name) == 0)
			break;

	/* return errorm on a bad reference */
	if (fnum == NFUNCS)
		return(errorm);

	/* if needed, retrieve the first argument */
	if (funcs[fnum].f_type >= MONAMIC) {
		if (macarg(arg1) != TRUE)
			return(errorm);

		/* if needed, retrieve the second argument */
		if (funcs[fnum].f_type >= DYNAMIC) {
			if (macarg(arg2) != TRUE)
				return(errorm);

			/* if needed, retrieve the third argument */
			if (funcs[fnum].f_type >= TRINAMIC)
				if (macarg(arg3) != TRUE)
					return(errorm);
		}
	}

	/* and now evaluate it! */
	switch (fnum) {
	case UFADD:
		it = l_itoa(l_strtol(arg1) + l_strtol(arg2));
		break;
	case UFSUB:
		it = l_itoa(l_strtol(arg1) - l_strtol(arg2));
		break;
	case UFTIMES:
		it = l_itoa(l_strtol(arg1) * l_strtol(arg2));
		break;
	case UFDIV:
		it = l_itoa(l_strtol(arg1) / l_strtol(arg2));
		break;
	case UFMOD:
		it = l_itoa(l_strtol(arg1) % l_strtol(arg2));
		break;
	case UFNEG:
		it = l_itoa(-l_strtol(arg1));
		break;
	case UFCAT:
		it = strcat(strcpy(result, arg1), arg2);
		break;
	case UFLEFT:
		it = strncpy0(result, arg1, s2size(arg2)+1);
		break;
	case UFRIGHT:
		it = strcpy(result, s2offset(arg1,arg2));
		break;
	case UFMID:
		it = strncpy0(result, s2offset(arg1,arg2), s2size(arg3)+1);
		break;
	case UFNOT:
		it = ltos(stol(arg1) == FALSE);
		break;
	case UFEQUAL:
		it = ltos(l_strtol(arg1) == l_strtol(arg2));
		break;
	case UFLESS:
		it = ltos(l_strtol(arg1) < l_strtol(arg2));
		break;
	case UFGREATER:
		it = ltos(l_strtol(arg1) > l_strtol(arg2));
		break;
	case UFSEQUAL:
		it = ltos(strcmp(arg1, arg2) == 0);
		break;
	case UFSLESS:
		it = ltos(strcmp(arg1, arg2) < 0);
		break;
	case UFSGREAT:
		it = ltos(strcmp(arg1, arg2) > 0);
		break;
	case UFIND:
		it = tokval(arg1);
		break;
	case UFAND:
		it = ltos(stol(arg1) && stol(arg2));
		break;
	case UFOR:
		it = ltos(stol(arg1) || stol(arg2));
		break;
	case UFLENGTH:
		it = l_itoa((int)strlen(arg1));
		break;
	case UFUPPER:
		it = mkupper(arg1);
		break;
	case UFLOWER:
		it = mklower(arg1);
		break;
	case UFTRIM:
		it = mktrimmed(arg1);
		break;
	case UFTRUTH:
		/* is it the answer to everything? */
		it = ltos(l_strtol(arg1) == 42);
		break;
	case UFASCII:
		it = l_itoa((int)arg1[0]);
		break;
	case UFCHR:
		result[0] = (char)l_strtol(arg1);
		result[1] = EOS;
		it = result;
		break;
	case UFGTKEY:
		result[0] = (char)keystroke_raw8();
		result[1] = EOS;
		it = result;
		break;
	case UFGTSEQ:
		(void)kcod2escape_seq(kbd_seq_nomap(), result);
		it = result;
		break;
	case UFRND:
		it = l_itoa((ernd() % absol(l_strtol(arg1))) + 1);
		break;
	case UFABS:
		it = l_itoa(absol(l_strtol(arg1)));
		break;
	case UFSINDEX:
		it = l_itoa(sindex(arg1, arg2));
		break;
	case UFENV:
		it = GetEnv(arg1);
		break;
	case UFBIND:
		it = prc2engl(arg1);
		break;
	case UFREADABLE:
		it = ltos(doglob(arg1)
			&& flook(arg1, FL_HERE|FL_READABLE) != NULL);
		break;
	case UFWRITABLE:
		it = ltos(doglob(arg1)
			&& flook(arg1, FL_HERE|FL_WRITEABLE) != NULL);
		break;
	case UFLOCMODE:
	case UFGLOBMODE:
		{ VALARGS args;
		if (find_mode(arg1, (fnum == UFGLOBMODE), &args) != TRUE)
			break;
		it = string_mode_val(&args);
		}
		break;
	default:
		it = errorm;
		break;
	}
	return it;
}

static const char *
gtusr(			/* look up a user var's value */
const char *vname)	/* name of user variable to fetch */
{
	register UVAR	*p;

	if (vname[0] != EOS) {
		for (p = user_vars; p != 0; p = p->next)
			if (!strcmp(vname, p->u_name))
				return p->u_value;
	}
	return (errorm);
}

char *
gtenv(const char *vname)	/* name of environment variable to retrieve */
{
	register int vnum;	/* ordinal number of var referenced */
	register char *value = errorm;
	BUFFER *bp;

	if (vname[0] != EOS) {

		/* scan the list, looking for the referenced name */
		for (vnum = 0; envars[vnum] != 0; vnum++)
			if (strcmp(vname, envars[vnum]) == 0)
				break;

		/* return errorm on a bad reference */
		if (envars[vnum] == 0) {
#if !SMALLER
			VALARGS	args;

			if (is_mode_name(vname, TRUE, &args) == TRUE)
				value = string_mode_val(&args);
#endif
			return (value);
		}


		/* otherwise, fetch the appropriate value */

		/* NOTE -- if you get a compiler error from this code, find
			the definitions of If and ElseIf up above, and add your
			system to the set of those with broken compilers that need
			to use ifs instead of a switch statement */

		If( EVPAGELEN )		value = l_itoa(term.t_nrow);
		ElseIf( EVCURCOL )	value = l_itoa(getccol(FALSE) + 1);
		ElseIf( EVCURLINE )	value = l_itoa(getcline());
#if OPT_RAMSIZE
		ElseIf( EVRAM )		value = l_itoa((int)(envram / 1024l));
#endif
		ElseIf( EVFLICKER )	value = ltos(flickcode);
		ElseIf( EVCURWIDTH )	value = l_itoa(term.t_ncol);
		ElseIf( EVBCHARS )
			bsizes(curbp);
			value = l_itoa(curbp->b_bytecount);
		ElseIf( EVBLINES )
			bsizes(curbp);
			value = l_itoa(curbp->b_linecount);
		ElseIf( EVCBUFNAME )	value = curbp->b_bname;
		ElseIf( EVABUFNAME )	value = ((bp = find_alt()) != 0)
						? bp->b_bname
						: "";
		ElseIf( EVCFNAME )	value = curbp ? curbp->b_fname : "";
		ElseIf( EVSRES )	value = sres;
		ElseIf( EVDEBUG )	value = ltos(macbug);
		ElseIf( EVSTATUS )	value = ltos(cmdstatus);
		ElseIf( EVPALETTE )	value = tb_values(palstr);
		ElseIf( EVLASTKEY )	value = l_itoa(lastkey);
		ElseIf( EVCURCHAR )
			if (curbp && !is_empty_buf(curbp)) {
				value = is_at_end_of_line(DOT)
					? l_itoa('\n')
					: l_itoa(char_at(DOT));
			}

		ElseIf( EVDISCMD )	value = ltos(discmd);
		ElseIf( EVPATCHLEVEL )	value = PATCHLEVEL;
		ElseIf( EVVERSION )	value = version;
		ElseIf( EVPROGNAME )	value = prognam;
		ElseIf( EVOS )		value = opersys;
		ElseIf( EVSEED )	value = l_itoa(seed);
		ElseIf( EVDISINP )	value = ltos(disinp);
		ElseIf( EVWLINES )	value = l_itoa(curwp->w_ntrows);
		ElseIf( EVCWLINE )	value = l_itoa(getwpos());
		ElseIf( EVFWD_SEARCH )	value = ltos(last_srch_direc == FORWARD);
		ElseIf( EVSEARCH )	value = pat;
		ElseIf( EVREPLACE )	value = rpat;
		ElseIf( EVMATCH )	value = (patmatch == NULL) ?
							"" : patmatch;
		ElseIf( EVMODE )	value = current_modename();
		ElseIf( EVEOC )		value = l_itoa(ev_end_of_cmd ? 1 : 0);
#if OPT_MLFORMAT
		ElseIf( EVMLFORMAT )
			if (modeline_format == 0)
				mlwrite("BUG: modeline_format uninitialized");
			value = modeline_format;
#endif

		ElseIf( EVMODIFIED )	value = ltos(curbp && b_is_changed(curbp));
		ElseIf( EVKILL )	value = getkill();
		ElseIf( EVTPAUSE )	value = l_itoa(term.t_pause);
		ElseIf( EVPENDING )	value = ltos(keystroke_avail());
		ElseIf( EVLLENGTH )	value = l_itoa(llength(DOT.l));
#if OPT_MAJORMODE
		ElseIf( EVMAJORMODE )	value = (curbp->majr != 0)
						? curbp->majr->name
						: "";
#endif
		ElseIf( EVLINE )	value = getctext((CHARTYPE)0);
		ElseIf( EVWORD )	value = getctext(vl_nonspace);
		ElseIf( EVIDENTIF )	value = getctext(vl_ident);
		ElseIf( EVQIDENTIF )	value = getctext(vl_qident);
		ElseIf( EVPATHNAME )	value = getctext(vl_pathn);
#if SYS_UNIX
		ElseIf( EVPROCESSID )	value = l_itoa(getpid());
#endif
#if OPT_SHELL
		ElseIf( EVCWD )		value = current_directory(FALSE);
		ElseIf( EVOCWD )	value = previous_directory();
#endif
#if OPT_PROCEDURES
		ElseIf( EVCDHOOK )	value = cdhook;
		ElseIf( EVRDHOOK )	value = readhook;
		ElseIf( EVWRHOOK )	value = writehook;
		ElseIf( EVBUFHOOK )	value = bufhook;
		ElseIf( EVEXITHOOK )	value = exithook;
#endif
#if SYS_WINNT && defined(DISP_NTWIN)
		ElseIf( EVFONT )	value = ntwinio_current_font();
#endif
#if OPT_SHELL
#if DISP_X11
		ElseIf( EVFONT )	value = x_current_fontname();
		ElseIf( EVTITLE )	value = x_get_window_name();
		ElseIf( EVICONNAM )	value = x_get_icon_name();
		ElseIf( EVXDISPLAY )
			if (x_display == 0)
				SetEnv(&x_display, DftEnv("DISPLAY", "unix:0"));
			value = x_display;
		ElseIf( EVXSHELL )
			if (x_shell == 0)
				SetEnv(&x_shell, DftEnv("XSHELL", "xterm"));
			value = x_shell;
#endif
		ElseIf( EVSHELL )
			value = get_shell();

		ElseIf( EVDIRECTORY )
			if (directory == 0)
				SetEnv(&directory, DftEnv("TMP", P_tmpdir));
			value = directory;
#endif

		ElseIf( EVHELPFILE )	value = helpfile;

		ElseIf( EVSTARTUP_FILE ) value = startup_file;

		ElseIf( EVSTARTUP_PATH ) value = startup_path;

#if OPT_COLOR
		ElseIf( EVNCOLORS )	value = l_itoa(ncolors);
#endif

		ElseIf( EVNTILDES )	value = l_itoa(ntildes);

		EndIf
	}
	if (value == 0)
		value = errorm;
	return value;
}

static char *
getkill(void)		/* return some of the contents of the kill buffer */
{
	register SIZE_T size;	/* max number of chars to return */
	static char value[NSTRING];	/* temp buffer for value */

	if (kbs[0].kbufh == NULL)
		/* no kill buffer....just a null string */
		value[0] = EOS;
	else {
		/* copy in the contents... */
		if (kbs[0].kused < NSTRING)
			size = kbs[0].kused;
		else
			size = NSTRING - 1;
		(void)strncpy(value, (char *)(kbs[0].kbufh->d_chunk), size);
		value[size] = EOS;
	}

	/* and return the constructed value */
	return(value);
}

static void
FindVar(		/* find a variables type and name */
char *var,		/* name of var to get */
VDESC *vd)		/* structure to hold type and ptr */
{
	register UVAR *p;
	register int vnum;	/* subscript in variable arrays */
	register int vtype;	/* type to return */

fvar:
	vtype = vnum = ILLEGAL_NUM;
	vd->v_ptr = 0;

	if (!var[1]) {
		vd->v_type = vtype;
		return;
	}
	switch (var[0]) {

		case '$': /* check for legal enviromnent var */
			for (vnum = 0; envars[vnum] != 0; vnum++)
				if (strcmp(&var[1], envars[vnum]) == 0) {
					vtype = TKENV;
					break;
				}
#if !SMALLER
			if (vtype == ILLEGAL_NUM) {
				VALARGS	args;

				if (is_mode_name(&var[1], TRUE, &args) == TRUE) {
					vnum  = MODE_NUM;
					vtype = TKENV;
				}
			}
#endif
			break;

		case '%': /* check for existing legal user variable */
			for (p = user_vars; p != 0; p = p->next)
				if (!strcmp(var+1, p->u_name)) {
					vtype = TKVAR;
					vnum  = USER_NUM;
					vd->v_ptr = p;
					break;
				}
			if (vd->v_ptr == 0) {
				if ((p = typealloc(UVAR)) != 0
				 && (p->u_name = strmalloc(var+1)) != 0) {
					p->next    = user_vars;
					p->u_value = 0;
					user_vars  = vd->v_ptr = p;
					vtype = TKVAR;
					vnum  = USER_NUM;
				}
			}
			break;

		case '&':	/* indirect operator? */
			if (strncmp(var, "&ind", FUNC_NAMELEN) == 0) {
				/* grab token, and eval it */
				execstr = token(execstr, var, EOS);
				(void)strcpy(var, tokval(var));
				goto fvar;
			}
	}

	/* return the results */
	vd->v_num = vnum;
	vd->v_type = vtype;
}

/*
 * Handles name-completion for variables.  Note that since the first character
 * can be either a '$' or '%', we'll postpone name-completion until we've seen
 * a '$'.
 */
static int
vars_complete(
int	c,
char	*buf,
unsigned *pos)
{
	int	status;
	if (buf[0] == '$') {
		*pos -= 1;	/* account for leading '$', not in tables */
		status = kbd_complete(FALSE, c, buf+1, pos,
				(const char *)list_of_modes(), sizeof(char *));
		*pos += 1;
	} else {
		if (c != NAMEC) /* cancel the unget */
			unkeystroke(c);
		status = TRUE;
	}
	return status;
}

int
setvar(int f, int n)		/* set a variable */
	/* note: numeric arg can overide prompted value */
{
	register int status;	/* status return */
	static TBUFF *var;

	/* first get the variable to set.. */
	if (var == 0)
		tb_scopy(&var, "");
	status = kbd_reply("Variable to set: ", &var,
		mode_eol, '=', KBD_NOEVAL|KBD_LOWERC, vars_complete);
	if (status != TRUE)
		return(status);
	return PromptAndSet(tb_values(var), f, n);
}

static int
PromptAndSet(const char *name, int f, int n)
{
	register int status;	/* status return */
	VDESC vd;		/* variable num/type */
	char var[NLINE];
	char prompt[NLINE];
	char value[NLINE];	/* value to set variable to */

	/* check the legality and find the var */
	FindVar(strcpy(var, name), &vd);

	/* if its not legal....bitch */
	if (vd.v_type == ILLEGAL_NUM) {
		mlforce("[No such variable as '%s']", var);
		return(FALSE);
	} else if (vd.v_type == TKENV && vd.v_num == MODE_NUM) {
		VALARGS	args;
		(void)find_mode(var+1, -TRUE, &args);
		set_end_string('=');
		return adjvalueset(var+1, TRUE, -TRUE, &args);
	}

	/* get the value for that variable */
	if (f == TRUE)
		(void)strcpy(value, l_itoa(n));
	else {
		value[0] = EOS;
		(void)lsprintf(prompt, "Value of %s: ", var);
		status = mlreply(prompt, value, sizeof(value));
		if (status != TRUE)
			return(status);
	}

	/* and set the appropriate value */
	status = SetVarValue(&vd, value);

	if (status == ABORT)
		mlforce("[Variable %s is readonly]", var);
	else if (status != TRUE)
		mlforce("[Cannot set %s to %s]", var, value);
	/* and return it */
	return(status);
}

int
stenv(const char *name, const char *value)
{
	register int status;	/* status return */
	VDESC vd;		/* variable num/type */
	char var[NLINE];

	/* check the legality and find the var */
	var[0] = '$';
	strcpy(var+1, name);
	FindVar(var, &vd);
	if (vd.v_type == ILLEGAL_NUM) {
		return(FALSE);
	}
	/* and set the appropriate value */
	status = SetVarValue(&vd, value);
	return status;
}

/* entrypoint from modes.c, used to set environment variables */
#if OPT_EVAL
int
set_variable(const char *name)
{
	char	temp[NLINE];
	if (*name != '$')
		(void) strcat(strcpy(temp, "$"), name);
	else
		(void) strcpy(temp, name);
	return PromptAndSet(temp, FALSE, 0);
}
#endif

static int
SetVarValue(	/* set a variable */
VDESC *var,	/* variable to set */
const char *value)	/* value to set to */
{
	register UVAR *vptr;
	register int vnum;	/* ordinal number of var referenced */
	register int vtype;	/* type of variable to set */
	register int status;	/* status return */
	register int c;		/* translated character */

	/* simplify the vd structure (we are gonna look at it a lot) */
	vptr = var->v_ptr;
	vnum = var->v_num;
	vtype = var->v_type;

	/* and set the appropriate value */
	status = TRUE;
	switch (vtype) {
	case TKVAR: /* set a user variable */
		FreeIfNeeded(vptr->u_value);
		if ((vptr->u_value = strmalloc(value)) == 0)
			status = FALSE;
		break;

	case TKENV: /* set an environment variable */
		status = TRUE;	/* by default */
		If( EVCURCOL )
			status = gotocol(TRUE, atoi(value));

		ElseIf( EVCURLINE )
			status = gotoline(TRUE, atoi(value));

		ElseIf( EVFLICKER )
			flickcode = stol(value);

		ElseIf( EVCURWIDTH )
#if DISP_X11 || DISP_NTWIN
			gui_resize(atoi(value), term.t_nrow);
#else
			status = newwidth(TRUE, atoi(value));
#endif

		ElseIf( EVPAGELEN )
#if DISP_X11 || DISP_NTWIN
			gui_resize(term.t_ncol, atoi(value));
#else
			status = newlength(TRUE, atoi(value));
#endif

		ElseIf( EVCBUFNAME )
			if (curbp) {
				set_bname(curbp, value);
				curwp->w_flag |= WFMODE;
			}

		ElseIf( EVCFNAME )
			if (curbp) {
				ch_fname(curbp, value);
				curwp->w_flag |= WFMODE;
			}

		ElseIf( EVSRES )
			status = TTrez(value);

		ElseIf( EVDEBUG )
			macbug = stol(value);

		ElseIf( EVSTATUS )
			cmdstatus = stol(value);

		ElseIf( EVPALETTE )
			status = set_palette(value);

		ElseIf( EVLASTKEY )
			lastkey = l_strtol(value);

		ElseIf( EVCURCHAR )
			if (curbp == NULL || b_val(curbp,MDVIEW))
				status = rdonly();
			else {
				mayneedundo();
				(void)ldelete(1L, FALSE); /* delete 1 char */
				c = l_strtol(value);
				if (c == '\n')
					status = lnewline();
				else
					status = linsert(1, c);
				(void)backchar(FALSE, 1);
			}

#if OPT_CRYPT
		ElseIf( EVCRYPTKEY )
			if (cryptkey != 0)
				free(cryptkey);
			cryptkey = strmalloc(value);
			ue_crypt((char *)NULL, 0);
			ue_crypt(cryptkey, strlen(cryptkey));
#endif
		ElseIf( EVDISCMD )
			discmd = stol(value);

		ElseIf( EVSEED )
			seed = atoi(value);

		ElseIf( EVDISINP )
			disinp = stol(value);

		ElseIf( EVWLINES )
			status = resize(TRUE, atoi(value));

		ElseIf( EVCWLINE )
			status = forwline(TRUE, atoi(value) - getwpos());

#if OPT_MLFORMAT
		ElseIf( EVMLFORMAT )
			SetEnv(&modeline_format, value);
			upmode();
#endif

		ElseIf( EVFWD_SEARCH )
			last_srch_direc = stol(value) ? FORWARD : REVERSE;

		ElseIf( EVSEARCH )
			(void)strcpy(pat, value);
			FreeIfNeeded(gregexp);
			gregexp = regcomp(pat, b_val(curbp, MDMAGIC));

		ElseIf( EVREPLACE )
			(void)strcpy(rpat, value);

		ElseIf( EVTPAUSE )
			term.t_pause = atoi(value);

		ElseIf( EVLINE ) 	status = putctext((CHARTYPE)0, value);
		ElseIf( EVWORD )	status = putctext(vl_nonspace, value);
		ElseIf( EVIDENTIF )	status = putctext(vl_ident, value);
		ElseIf( EVQIDENTIF )	status = putctext(vl_qident, value);
		ElseIf( EVPATHNAME )	status = putctext(vl_pathn, value);

#if SYS_WINNT && defined(DISP_NTWIN)
		ElseIf( EVFONT ) status = ntwinio_font_frm_str(value, FALSE);
#endif
#if OPT_SHELL
#if DISP_X11
		ElseIf( EVFONT ) status = x_setfont(value);
		ElseIf( EVTITLE ) x_set_window_name(value);
		ElseIf( EVICONNAM ) x_set_icon_name(value);
		ElseIf( EVXDISPLAY ) SetEnv(&x_display, value);
		ElseIf( EVXSHELL ) SetEnv(&x_shell, value);
#endif
		ElseIf( EVCWD )
			status = set_directory(value);

		ElseIf( EVSHELL )
			SetEnv(&shell, value);

		ElseIf( EVDIRECTORY )
			SetEnv(&directory, value);
#endif

		ElseIf( EVHELPFILE )
			SetEnv(&helpfile, value);

		ElseIf( EVSTARTUP_FILE )
			SetEnv(&startup_file, value);

		ElseIf( EVSTARTUP_PATH )
			SetEnv(&startup_path, value);

#if OPT_PROCEDURES
		ElseIf( EVCDHOOK )     (void)strcpy(cdhook, value);
		ElseIf( EVRDHOOK )     (void)strcpy(readhook, value);
		ElseIf( EVWRHOOK )     (void)strcpy(writehook, value);
		ElseIf( EVBUFHOOK )    (void)strcpy(bufhook, value);
		ElseIf( EVEXITHOOK )   (void)strcpy(exithook, value);
#endif

#if OPT_COLOR
		ElseIf( EVNCOLORS )	status = set_ncolors(atoi(value));
#endif

		ElseIf( EVNTILDES )
			ntildes = atoi(value);
			if (ntildes > 100)
				ntildes = 100;

		Otherwise
			/* EVABUFNAME */
			/* EVBLENGTH */
			/* EVPROGNAME */
			/* EVPATCHLEVEL */
			/* EVVERSION */
			/* EVMATCH */
			/* EVKILL */
			/* EVPENDING */
			/* EVLLENGTH */
			/* EVMAJORMODE */
			/* EVMODIFIED */
			/* EVPROCESSID */
			/* EVRAM */
			/* EVMODE */
			/* EVOS */
			status = ABORT;	/* must be readonly */
		EndIf
		break;
	}
#if	OPT_DEBUGMACROS
	/* if $debug == TRUE, every assignment will echo a statment to
	   that effect here. */

	if (macbug) {
		char	outline[NLINE];
		(void)strcpy(outline, "(((");

		/* assignment status */
		(void)strcat(outline, ltos(status));
		(void)strcat(outline, ":");

		/* variable name */
		if (var->v_type == TKENV) {
			(void)strcat(outline, "&");
			(void)strcat(outline, envars[var->v_num]);
		} else if (var->v_type == TKENV) {
			(void)strcat(outline, "%");
			(void)strcat(outline, var->v_ptr->u_name);
		}
		(void)strcat(outline, ":");

		/* and lastly the value we tried to assign */
		(void)strcat(outline, value);
		(void)strcat(outline, ")))");


		/* write out the debug line */
		mlforce("%s",outline);
		(void)update(TRUE);

		/* and get the keystroke to hold the output */
		if (ABORTED(keystroke())) {
			mlforce("[Macro aborted]");
			status = FALSE;
		}
	}
#endif
	return(status);
}
#endif

const char *
skip_cblanks(const char *src)
{
	while (isSpace(*src))
		src++;
	return src;
}

const char *
skip_cstring(const char *src)
{
	return src + strlen(src);
}

const char *
skip_ctext(const char *src)
{
	while (*src != EOS && !isSpace(*src))
		src++;
	return src;
}

/* If we've #define'd const, it's because it doesn't work.  Conversely, if
 * it's not #define'd, we really need distinct string functions.
 */
#ifndef const
char *
skip_blanks(char *src)
{
	while (isSpace(*src))
		src++;
	return src;
}

char *
skip_string(char *src)
{
	return src + strlen(src);
}

char *
skip_text(char *src)
{
	while (*src != EOS && !isSpace(*src))
		src++;
	return src;
}
#endif

#if OPT_COLOR
void
set_ctrans(const char *thePalette)
{
	int n = 0, value;
	char *next;

	while (*thePalette != EOS) {
		thePalette = skip_cblanks(thePalette);
		value = (int) strtol(thePalette, &next, 0);
		if (next == thePalette)
			break;
		thePalette = next;
		ctrans[n] = value;
		if (++n >= NCOLORS)
			break;
	}
}
#endif

/*
 * This function is used in several terminal drivers.
 */
#if OPT_EVAL || OPT_COLOR
int
set_palette(const char *value)
{
	palstr = tb_scopy(&palstr, value);
#if OPT_COLOR
	if (term.t_setpal != null_t_setpal) {
		TTspal(tb_values(palstr));
		vile_refresh(FALSE,0);
		return TRUE;
	}
	return FALSE;
#else
	return TRUE;
#endif
}
#endif

/*	l_itoa:	integer to ascii string.......... This is too
		inconsistent to use the system's	*/

char *
l_itoa(int i)		/* integer to translate to a string */
{
	static char result[INTWIDTH+1];	/* resulting string */
	(void)lsprintf(result,"%d",i);
	return result;
}


/* like strtol, but also allow character constants */
#if OPT_EVAL
static int
l_strtol(const char *s)
{
	if (s[0] == '\'' &&
	    s[2] == '\'' &&
	    s[3] == EOS)
	    return s[1];
	return (int)strtol(s, (char **)0, 0);
}
#endif

int
toktyp(			/* find the type of a passed token */
const char *tokn)	/* token to analyze */
{

	/* no blanks!!! */
	if (tokn[0] == EOS)
		return(TKNUL);

	/* a numeric literal? */
	if (isDigit(tokn[0]))
		return(TKLIT);

	if (tokn[0] == '"')
		return(TKSTR);

	/* if it's any other single char, it must be itself */
	if (tokn[1] == EOS)
		return(TKCMD);

#if ! SMALLER
	switch (tokn[0]) {
		case '"':	return(TKSTR);

		case '~':	return(TKDIR);
		case '@':	return(TKARG);
		case '<':	return(TKBUF);
		case '$':	return(TKENV);
		case '%':	return(TKVAR);
		case '&':	return(TKFUN);
		case '*':	return(TKLBL);

		default:	return(TKCMD);
	}
#else
	return(TKCMD);
#endif
}

const char *
tokval(				/* find the value of a token */
const char *tokn)		/* token to evaluate */
{
#if OPT_EVAL
	register int status;	/* error return */
	register BUFFER *bp;	/* temp buffer pointer */
	register B_COUNT blen;	/* length of buffer argument */
	register int distmp;	/* temporary discmd flag */
	int	oclexec;
	static char buf[NSTRING];/* string buffer for some returns */

	switch (toktyp(tokn)) {
		case TKNUL:	return("");

		case TKARG:	/* interactive argument */
				{
				static char tkargbuf[NSTRING];

				oclexec = clexec;

				distmp = discmd;	/* echo it always! */
				discmd = TRUE;
				clexec = FALSE;
				status = kbd_string(tokval(&tokn[1]), tkargbuf,
						sizeof(buf), '\n',
						KBD_EXPAND|KBD_QUOTES,
						no_completion);
				discmd = distmp;
				clexec = oclexec;

				if (status == ABORT)
					return(errorm);
				return(tkargbuf);
				}

		case TKBUF:	/* buffer contents fetch */

				/* grab the right buffer */
				if ((bp = find_b_name(tokval(&tokn[1]))) == NULL)
					return(errorm);

				/* if the buffer is displayed, get the window
				   vars instead of the buffer vars */
				if (bp->b_nwnd != 0) {
					curbp->b_dot = DOT;
				}

				/* make sure we are not at the end */
				if (is_header_line(bp->b_dot,bp))
					return(errorm);

				/* grab the line as an argument */
				blen = llength(bp->b_dot.l);
				if (blen > bp->b_dot.o)
					blen -= bp->b_dot.o;
				else
					blen = 0;
				if (blen > NSTRING)
					blen = NSTRING;
				(void)strncpy(buf,
					bp->b_dot.l->l_text + bp->b_dot.o,
					(SIZE_T)blen);
				buf[blen] = (char)EOS;

				/* and step the buffer's line ptr
					ahead a line */
				bp->b_dot.l = lforw(bp->b_dot.l);
				bp->b_dot.o = 0;

				/* if displayed buffer, reset window ptr vars*/
				if (bp->b_nwnd != 0) {
					DOT.l = curbp->b_dot.l;
					DOT.o = 0;
					curwp->w_flag |= WFMOVE;
				}

				/* and return the spoils */
				return(buf);

		case TKVAR:	return(gtusr(tokn+1));
		case TKENV:	return(gtenv(tokn+1));
		case TKFUN:	return(gtfun(tokn+1));
		case TKDIR:
#if SYS_UNIX
				return(lengthen_path(strcpy(buf,tokn)));
#else
				return(errorm);
#endif
		case TKLBL:	return(l_itoa(gtlbl(tokn)));
		case TKLIT:	return(tokn);
		case TKSTR:	return(tokn+1);
		case TKCMD:	return(tokn);
	}
	return errorm;
#else
	return (toktyp(tokn) == TKSTR) ? tokn+1 : tokn;
#endif
}

/*
 * Return true if the argument is one of the strings that we accept as a
 * synonym for "true".
 */
int
is_truem(const char *val)
{
	char	temp[8];
	(void)mklower(strncpy0(temp, val, sizeof(temp)));
	return (!strcmp(temp, "yes")
	   ||   !strcmp(temp, "true")
	   ||   !strcmp(temp, "t")
	   ||   !strcmp(temp, "y")
	   ||   !strcmp(temp, "on"));
}

/*
 * Return true if the argument is one of the strings that we accept as a
 * synonym for "false".
 */
int
is_falsem(const char *val)
{
	char	temp[8];
	(void)mklower(strncpy0(temp, val, sizeof(temp)));
	return (!strcmp(temp, "no")
	   ||   !strcmp(temp, "false")
	   ||   !strcmp(temp, "f")
	   ||   !strcmp(temp, "n")
	   ||   !strcmp(temp, "off"));
}

#if OPT_EVAL || DISP_X11
int
stol(			/* convert a string to a numeric logical */
const char *val)	/* value to check for stol */
{
	/* check for logical values */
	if (is_falsem(val))
		return(FALSE);
	if (is_truem(val))
		return(TRUE);

	/* check for numeric truth (!= 0) */
	return((atoi(val) != 0));
}
#endif

#if OPT_EVAL
/* use this as a wrapper when evaluating an array index, etc., that cannot
 * be negative.
 */
static SIZE_T
s2size(char *s)
{
	int	n = atoi(s);
	if (n < 0)
		n = 0;
	return n;
}

/* use this to return a pointer to the string after the n-1 first characters */
static char *
s2offset(char *s, char *n)
{
	SIZE_T	len = strlen(s) + 1;
	UINT	off = s2size(n);
	if (off > len)
		off = len;
	if (off == 0)
		off = 1;
	return s + (off - 1);
}

LINE *
label2lp (BUFFER *bp, const char *label)
{
	LINE *glp;
	LINE *result = 0;
	size_t len = strlen(label);

	if (len > 1) {
		for_each_line(glp, bp) {
			int need = len + 1;
			if (glp->l_used >= need
			 && glp->l_text[0] == '*'
			 && !memcmp(&glp->l_text[1], label, len)) {
				result = glp;
				break;
			}
		}
	}
	return(result);
}

/* ARGSUSED */
static int
gtlbl(				/* find the line number of the given label */
const char *tokn)		/* label name to find */
{
	LINE *lp = label2lp(curbp, tokn);
	int result = 0;

	if (lp != 0)
		result = line_no(curbp, lp);
	return(result);
}

static char *
ltos(		/* numeric logical to string logical */
int val)	/* value to translate */
{
	if (val)
		return(truem);
	else
		return(falsem);
}
#endif

#if OPT_EVAL || !SMALLER
char *
mkupper(		/* make a string upper case */
char *str)		/* string to upper case */
{
	char *sp;

	sp = str;
	while (*sp) {
		if (isLower(*sp))
			*sp = toUpper(*sp);
		++sp;
	}
	return(str);
}
#endif

char *
mklower(		/* make a string lower case */
char *str)		/* string to lower case */
{
	char *sp;

	sp = str;
	while (*sp) {
		if (isUpper(*sp))
			*sp = toLower(*sp);
		++sp;
	}
	return(str);
}

char *
mktrimmed(register char *str)	/* trim whitespace */
{
	char *base = str;
	register char *dst = str;

	while (*str != EOS) {
		if (isSpace(*str)) {
			if (dst != base)
				*dst++ = ' ';
			str = skip_blanks(str);
		} else {
			*dst++ = *str++;
		}
	}
	if (dst != base
	 && isSpace(dst[-1]))
	 	dst--;
	*dst = EOS;
	return base;
}

int
absol(int x)		/* take the absolute value of an integer */
{
	return(x < 0 ? -x : x);
}

#if OPT_EVAL
static int
ernd(void)		/* returns a random integer */
{
	seed = absol(seed * 1721 + 10007);
	return(seed);
}

static int
sindex(			/* find pattern within source */
const char *sourc,	/* source string to search */
const char *pattern)	/* string to look for */
{
	int it = 0;		/* assume no match at all.. */
	const char *sp;		/* ptr to current position to scan */
	const char *csp;	/* ptr to source string during comparison */
	const char *cp;		/* ptr to place to check for equality */

	/* scanning through the source string */
	sp = sourc;
	while (*sp) {
		/* scan through the pattern */
		cp = pattern;
		csp = sp;
		while (*cp) {
			if (!eq(*cp, *csp))
				break;
			++cp;
			++csp;
		}

		/* was it a match? */
		if (*cp == 0) {
			it = (int)(sp - sourc) + 1;
			break;
		}
		++sp;
	}

	return(it);
}

#endif /* OPT_EVAL */

#if NO_LEAKS
void
ev_leaks(void)
{
#if OPT_EVAL
	register UVAR *p;
	while ((p = user_vars) != 0) {
		user_vars = p->next;
		free(p->u_value);
		free(p->u_name);
		free((char *)p);
	}
	FreeAndNull(shell);
	FreeAndNull(directory);
#if DISP_X11
	FreeAndNull(x_display);
	FreeAndNull(x_shell);
#endif
#endif
}
#endif	/* NO_LEAKS */
