/usr/src/usr.bin/mg/interpreter.c

Bug Summary

File:	src/usr.bin/mg/interpreter.c
Warning:	line 280, column 10 The left operand of '==' is a garbage value

Annotated Source Code

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clang -cc1 -cc1 -triple amd64-unknown-openbsd7.4 -analyze -disable-free -clear-ast-before-backend -disable-llvm-verifier -discard-value-names -main-file-name interpreter.c -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -setup-static-analyzer -mrelocation-model pic -pic-level 1 -pic-is-pie -mframe-pointer=all -relaxed-aliasing -ffp-contract=on -fno-rounding-math -mconstructor-aliases -funwind-tables=2 -target-cpu x86-64 -target-feature +retpoline-indirect-calls -target-feature +retpoline-indirect-branches -tune-cpu generic -debugger-tuning=gdb -fcoverage-compilation-dir=/usr/src/usr.bin/mg/obj -resource-dir /usr/local/llvm16/lib/clang/16 -D REGEX -internal-isystem /usr/local/llvm16/lib/clang/16/include -internal-externc-isystem /usr/include -O2 -fdebug-compilation-dir=/usr/src/usr.bin/mg/obj -ferror-limit 19 -fwrapv -D_RET_PROTECTOR -ret-protector -fcf-protection=branch -fno-jump-tables -fgnuc-version=4.2.1 -vectorize-loops -vectorize-slp -fno-builtin-malloc -fno-builtin-calloc -fno-builtin-realloc -fno-builtin-valloc -fno-builtin-free -fno-builtin-strdup -fno-builtin-strndup -analyzer-output=html -faddrsig -D__GCC_HAVE_DWARF2_CFI_ASM=1 -o /home/ben/Projects/scan/2024-01-11-140451-98009-1 -x c /usr/src/usr.bin/mg/interpreter.c

1/*      $OpenBSD: interpreter.c,v 1.35 2023/04/17 10:11:30 op Exp $	*/
2/*
* This file is in the public domain.
*
* Author: Mark Lumsden <mark@showcomplex.com>
*/

8/*
* This file attempts to add some 'scripting' functionality into mg.
*
* The initial goal is to give mg the ability to use its existing functions
* and structures in a linked-up way. Hopefully resulting in user definable
* functions. The syntax is 'scheme' like but currently it is not a scheme
* interpreter.
*
* At the moment there is no manual page reference to this file. The code below
* is liable to change, so use at your own risk!
*
* If you do want to do some testing, you can add some lines to your .mg file
* like:
* 
* 1. Give multiple arguments to a function that usually would accept only one:
* (find-file "a.txt" "b.txt" "c.txt")
*
* 2. Define a single value variable:
* (define myfile "d.txt")
*
* 3. Define a list:
* (define myfiles(list "e.txt" "f.txt"))
*
* 4. Use the previously defined variable or list:
* (find-file myfiles)
*
* To do:
* 1. multiline parsing - currently only single lines supported.
* 2. parsing for '(' and ')' throughout whole string and evaluate correctly.
* 3. conditional execution.
* 4. have memory allocated dynamically for variable values.
* 5. do symbol names need more complex regex patterns? [A-Za-z][.0-9_A-Z+a-z-]
*    at the moment.
* 6. display line numbers with parsing errors.
* 7. oh so many things....
* [...]
* n. implement user definable functions.
* 
* Notes:
* - Currently calls to excline() from this file have the line length and
*   line number set to zero.
*   That's because excline() uses '\0' as the end of line indicator
*   and only the call to foundparen() within excline() uses excline's 2nd
*   and 3rd arguments.
*   Importantly, any lines sent to there from here will not be
*   coming back here.
*/
55#include <sys/queue.h>

57#include <ctype.h>
58#include <limits.h>
59#include <regex.h>
60#include <signal.h>
61#include <stdio.h>
62#include <stdlib.h>
63#include <string.h>

65#include "def.h"
66#include "funmap.h"

68#ifdef  MGLOG
69#include "kbd.h"
70#include "log.h"
71#endif

73static int	 multiarg(char *, char *, int);
74static int	 isvar(char **, char **, int);
75/*static int	 dofunc(char **, char **, int);*/
76static int	 founddef(char *, int, int, int, int);
77static int	 foundlst(char *, int, int, int);
78static int	 expandvals(char *, char *, char *);
79static int	 foundfun(char *, int);
80static int	 doregex(char *, char *);
81static void	 clearexp(void);
82static int	 parse(char *, const char *, const char *, int, int, int, int);
83static int	 parsdef(char *, const char *, const char *, int, int, int);
84static int	 parsval(char *, const char *, const char *, int, int, int);
85static int	 parsexp(char *, const char *, const char *, int, int, int);

87static int	 exitinterpreter(char *, char *, int);

89TAILQ_HEAD(exphead, expentry)struct exphead { struct expentry *tqh_first; struct expentry *
*tqh_last; } ehead;
90struct expentry {
TAILQ_ENTRY(expentry)struct { struct expentry *tqe_next; struct expentry **tqe_prev
; } eentry;
char	*fun;		/* The 1st string found between parens.   */
char	 funbuf[BUFSIZE128];
const char	*par1;	/* Parenthesis at start of string	  */
const char	*par2;	/* Parenthesis at end of string		  */
int	 expctr;	/* An incremental counter:+1 for each exp */
int	 blkid;		/* Which block are we in?		  */
98};

100/*
* Structure for scheme keywords. 
*/
103#define NUMSCHKEYS4	4
104#define MAXLENSCHKEYS17	17	/* 17 = longest keyword (16)  + 1 */

106char scharkey[NUMSCHKEYS4][MAXLENSCHKEYS17] =
{ 
"define",
 	"list",
 	"if",
 	"lambda"
};

114static const char 	 lp = '(';
115static const char 	 rp = ')';
116static char 		*defnam = NULL((void *)0);
117static int		 lnm;

119/*
* Line has a '(' as the first non-white char.
* Do some very basic parsing of line.
* Multi-line not supported at the moment, To do.
*/
124int
125foundparen(char *funstr, int llen, int lnum)
126{
const char	*lrp = NULL((void *)0);
char		*p, *begp = NULL((void *)0), *endp = NULL((void *)0), *prechr;
char		*lastchr = NULL((void *)0);
int     	 i, ret, pctr, expctr, blkid, inquote, esc;
1
'ret' declared without an initial value→
int		 elen, spc, ns;

pctr = expctr = inquote = esc = elen = spc = ns = 0;
blkid = 1;
lnm = lnum;

/*
* load expressions into a list called 'expentry', to be processd
* when all are obtained.
* Not really live code at the moment. Just part of the process of
* working out what needs to be done.
*/
TAILQ_INIT(&ehead)do { (&ehead)->tqh_first = ((void *)0); (&ehead)->
tqh_last = &(&ehead)->tqh_first; } while (0);
2
←
Loop condition is false.  Exiting loop→

/*
* Check for blocks of code with opening and closing ().
* One block = (cmd p a r a m)
* Two blocks = (cmd p a r a m s)(hola)
* Two blocks = (cmd p a r (list a m s))(hola)
* Only single line at moment, but more for multiline.
*/
p = funstr;

for (i = 0; i < llen; ++i, p++) {
3
←
Assuming 'i' is >= 'llen'→
4
←
Loop condition is false. Execution continues on line 275→
if (pctr == 0 && *p != ' ' && *p != '\t' && *p != '(') {
	if (*p == ')')
		return(dobeep_num("Extra ')' found on line:",
		    lnm));
	return(dobeep_num("Error line:", lnm));
}
if (begp != NULL((void *)0))
	elen++;

if (*p == '\\') {
	esc = 1;
} else if (*p == '(') {
	if (lastchr != NULL((void *)0) && *lastchr == '(')
		return(dobeep_num("Multiple consecutive "\
		    "left parantheses line", lnm));
	if (inquote == 0) {
		if (begp != NULL((void *)0)) {
			if (*prechr == ' ')
				ns--;
			if (endp == NULL((void *)0))
				*p = '\0';
			else
				*endp = '\0';

			ret = parse(begp, lrp, &lp, blkid,
			    ++expctr, elen - spc, ns);
			if (!ret) {
				cleanup();
				return(ret);
			}
			elen = 0;
		}
		lrp = &lp;
		begp = endp = NULL((void *)0);
		pctr++;
	} else if (inquote != 1) {
		cleanup();
		return(dobeep_num("Opening and closing quote "\
		    "char error line:", lnm));
	}
	esc = spc = 0;
} else if (*p == ')') {
	if (lastchr != NULL((void *)0) && *lastchr == '(')
		return(dobeep_num("Empty parenthesis "\
		    "not supported line", lnm));
	if (inquote == 0) {
		if (begp != NULL((void *)0)) {
			if (*prechr == ' ')
				ns--;
			if (endp == NULL((void *)0))
				*p = '\0';
			else
				*endp = '\0';

			ret = parse(begp, lrp, &rp, blkid,
			    ++expctr, elen - spc, ns);
			if (!ret) {
				cleanup();
				return(ret);
			}
			elen = 0;
		}
		lrp = &rp;
		begp = endp = NULL((void *)0);
		pctr--;
	} else if (inquote != 1) {
		cleanup();
		return(dobeep_num("Opening and closing quote "\
		    "char error line:", lnm));
	}
	esc = spc = 0;
} else if (*p != ' ' && *p != '\t') {
	if (begp == NULL((void *)0)) {
		begp = p;
		if (*begp == '"' || isdigit(*begp))
			return(dobeep_num("First char of "\
			    "expression error line:", lnm));
	}
	if (*p == '"') {
		if (inquote == 0 && esc == 0) {
			if (*prechr != ' ' && *prechr != '\t')
				return(dobeep_num("Parse error"\
				    " line:", lnm));
			inquote++;
		} else if (inquote > 0 && esc == 1)
			esc = 0;
		else
			inquote--;
	} else if (*prechr == '"' && inquote == 0) {
		return(dobeep_num("Parse error line:", lnm));
	}
	endp = NULL((void *)0);
	spc = 0;
} else if (endp == NULL((void *)0) && (*p == ' ' || *p == '\t')) {
	if (inquote == 0) {
		*p = ' ';
		endp = p;
		spc++;
		if (begp != NULL((void *)0))
			ns++;
	}
	esc = 0;
} else if (*p == '\t' || *p == ' ') {
	if (inquote == 0) {
		*p = ' ';
		spc++;
	}
	esc = 0;
}
if (*p != '\t' && *p != ' ' && inquote == 0)
	lastchr = p;

if (pctr == 0) {
	blkid++;
	expctr = 0;
	defnam = NULL((void *)0);
}
prechr = p;
}

if (pctr4.1
'pctr' is equal to 0
 != 0) {
5
←
Taking false branch→
cleanup();
return(dobeep_num("Opening and closing parentheses error line:",
    lnm));
}
if (ret == FALSE0)
6
←
The left operand of '==' is a garbage value
cleanup();
else
clearexp();	/* leave lists but remove expressions */

return (ret);
286}


289static int
290parse(char *begp, const char *par1, const char *par2, int blkid, int expctr,
  int elen, int ns)
292{
char    *regs;
int 	 ret = FALSE0;

if (strncmp(begp, "define", 6) == 0) {
ret = parsdef(begp, par1, par2, blkid, expctr, elen);
if (ret == TRUE1 || ret == FALSE0)
	return (ret);
} else if (strncmp(begp, "list", 4) == 0)
return(parsval(begp, par1, par2, blkid, expctr, elen));

regs = "^exit$";
if (doregex(regs, begp))
return(exitinterpreter(NULL((void *)0), NULL((void *)0), FALSE0));

/* mg function name regex */	
regs = "^[A-Za-z-]+$";
      if (doregex(regs, begp))
return(excline(begp, 0, 0));

/* Corner case 1 */
if (strncmp(begp, "global-set-key ", 15) == 0)
/* function name as 2nd param screws up multiarg. */
return(excline(begp, 0, 0));

/* Corner case 2 */
if (strncmp(begp, "define-key ", 11) == 0)
/* function name as 3rd param screws up multiarg. */
return(excline(begp, 0, 0));

return (parsexp(begp, par1, par2, blkid, expctr, elen));
323}

325static int
326parsdef(char *begp, const char *par1, const char *par2, int blkid, int expctr,
  int elen)
328{
char    *regs;

if ((defnam == NULL((void *)0)) && (expctr != 1))
return(dobeep_num("'define' incorrectly used line:", lnm));

      /* Does the line have a incorrect variable 'define' like: */
      /* (define i y z) */
      regs = "^define[ ]+[A-Za-z][.0-9_A-Z+a-z-]*[ ]+.+[ ]+.+$";
      if (doregex(regs, begp))
              return(dobeep_num("Invalid use of define line:", lnm));

      /* Does the line have a single variable 'define' like: */
      /* (define i 0) */
      regs = "^define[ ]+[A-Za-z][.0-9_A-Z+a-z-]*[ ]+.*$";
      if (doregex(regs, begp)) {
if (par1 == &lp && par2 == &rp && expctr == 1)
	return(founddef(begp, blkid, expctr, 1, elen));
return(dobeep_num("Invalid use of define line:", lnm));
}
/* Does the line have  '(define i(' */
      regs = "^define[ ]+[A-Za-z][.0-9_A-Z+a-z-]*[ ]*$";
      if (doregex(regs, begp)) {
if (par1 == &lp && par2 == &lp && expctr == 1)
              	return(founddef(begp, blkid, expctr, 0, elen));
return(dobeep_num("Invalid use of 'define' line:", lnm));
}
/* Does the line have  '(define (' */
regs = "^define$";
if (doregex(regs, begp)) {
if (par1 == &lp && par2 == &lp && expctr == 1)
	return(foundfun(begp, expctr));
return(dobeep_num("Invalid use of 'define' line:", lnm));
}

return (ABORT2);
364}

366static int
367parsval(char *begp, const char *par1, const char *par2, int blkid, int expctr,
  int elen)
369{
char    *regs;

/* Does the line have 'list' */
regs = "^list$";
if (doregex(regs, begp))
return(dobeep_num("Invalid use of list line:", lnm));

      /* Does the line have a 'list' like: */
      /* (list "a" "b") */
      regs = "^list[ ]+.*$";
      if (doregex(regs, begp)) {
if (expctr == 1)
	return(dobeep_num("list with no-where to go.", lnm));

if (par1 == &lp && expctr > 1)
	return(foundlst(begp, blkid, expctr, elen));

return(dobeep_num("Invalid use of list line:", lnm));
}
return (FALSE0);
390}

392static int
393parsexp(char *begp, const char *par1, const char *par2, int blkid, int expctr,
  int elen)
395{
struct expentry *e1 = NULL((void *)0);
PF		 funcp;
char		*cmdp, *fendp, *valp, *fname, *funb = NULL((void *)0);;
int		 numparams, ret;

cmdp = begp;
fendp = strchr(cmdp, ' ');
*fendp = '\0';

/*
* If no extant mg command found, just return.
*/
if ((funcp = name_function(cmdp)) == NULL((void *)0))
return (dobeep_msgs("Unknown command:", cmdp));

numparams = numparams_function(funcp);
if (numparams == 0)
return (dobeep_msgs("Command takes no arguments:", cmdp));

if (numparams == -1)
return (dobeep_msgs("Interactive command found:", cmdp));

if ((e1 = malloc(sizeof(struct expentry))) == NULL((void *)0)) {
cleanup();
return (dobeep_msg("malloc Error"));
}
TAILQ_INSERT_HEAD(&ehead, e1, eentry)do { if (((e1)->eentry.tqe_next = (&ehead)->tqh_first
) != ((void *)0)) (&ehead)->tqh_first->eentry.tqe_prev
 = &(e1)->eentry.tqe_next; else (&ehead)->tqh_last
 = &(e1)->eentry.tqe_next; (&ehead)->tqh_first =
 (e1); (e1)->eentry.tqe_prev = &(&ehead)->tqh_first
; } while (0);
if ((e1->fun = strndup(cmdp, BUFSIZE128)) == NULL((void *)0)) {
cleanup();
return(dobeep_msg("strndup error"));
}
cmdp = e1->fun;
fname = e1->fun;
e1->funbuf[0] = '\0';
funb = e1->funbuf;
e1->expctr = expctr;
e1->blkid = blkid;
/* need to think about these two */
e1->par1 = par1;
e1->par2 = par2;

*fendp = ' ';
valp = fendp + 1;

ret = expandvals(cmdp, valp, funb);
if (!ret)
return (ret);

return (multiarg(fname, funb, numparams));
445}

447/*
* Pass a list of arguments to a function.
*/
450static int
451multiarg(char *cmdp, char *argbuf, int numparams)
452{
char	 excbuf[BUFSIZE128];
char	*argp, *p, *s = " ";
char	*regs;
int	 spc, numspc;
int	 fin, inquote;

argp = argbuf;
spc = 1; /* initially fake a space so we find first argument */
numspc = fin = inquote = 0;

for (p = argbuf; *p != '\0'; p++) {
if (*(p + 1) == '\0')
	fin = 1;

if (*p != ' ') {
	if (*p == '"') {
		if (inquote == 1)
			inquote = 0;	
		else
			inquote = 1;
	}
	if (spc == 1)
		if ((numspc % numparams) == 0) {
			argp = p;
		}
	spc = 0;
}
if ((*p == ' ' && inquote == 0) || fin) {
	if (spc == 1)/* || (numspc % numparams == 0))*/
		continue;
	if ((numspc % numparams) != (numparams - 1)) {
		numspc++;
		continue;
	}
	if (*p == ' ') {
		*p = '\0';		/* terminate arg string */
	}
	excbuf[0] = '\0';
	regs = "[\"]+.*[\"]+";

     			if (!doregex(regs, argp)) {
		const char *errstr;

		strtonum(argp, 0, INT_MAX0x7fffffff, &errstr);
		if (errstr != NULL((void *)0))
			return (dobeep_msgs("Var not found:",
			    argp));
	}

	if (strlcpy(excbuf, cmdp, sizeof(excbuf))
	    >= sizeof(excbuf))
		return (dobeep_msg("strlcpy error"));
	if (strlcat(excbuf, s, sizeof(excbuf))
	    >= sizeof(excbuf))
		return (dobeep_msg("strlcat error"));
	if (strlcat(excbuf, argp, sizeof(excbuf))
	    >= sizeof(excbuf))
		return (dobeep_msg("strlcat error"));

	excline(excbuf, 0, 0);

	if (fin)
		break;

	*p = ' ';		/* unterminate arg string */
	numspc++;
	spc = 1;
}
}
return (TRUE1);
523}

525/*
* Is an item a value or a variable?
*/
528static int
529isvar(char **argp, char **varbuf, int sizof)
530{
struct varentry *v1 = NULL((void *)0);

if (SLIST_EMPTY(&varhead)(((&varhead)->slh_first) == ((void *)0)))
return (FALSE0);
535#ifdef  MGLOG
mglog_isvar(*varbuf, *argp, sizof);
537#endif
SLIST_FOREACH(v1, &varhead, entry)for((v1) = ((&varhead)->slh_first); (v1) != ((void *)0
); (v1) = ((v1)->entry.sle_next)) {
if (strcmp(*argp, v1->v_name) == 0) {
	(void)(strlcpy(*varbuf, v1->v_buf, sizof) >= sizof);
	return (TRUE1);
}
}
return (FALSE0);
545}


548static int
549foundfun(char *defstr, int expctr)
550{
return (TRUE1);
552}

554static int
555foundlst(char *defstr, int blkid, int expctr, int elen)
556{
char		*p;

p = strstr(defstr, " ");
p = skipwhite(p);
expandvals(NULL((void *)0), p, defnam);

return (TRUE1);
564}

566/*
* 'define' strings follow the regex in parsdef().
*/
569static int
570founddef(char *defstr, int blkid, int expctr, int hasval, int elen)
571{
struct varentry *vt, *v1 = NULL((void *)0);
char		*p, *vnamep, *vendp = NULL((void *)0), *valp;

p = strstr(defstr, " ");        /* move to first ' ' char.    */
vnamep = skipwhite(p);		/* find first char of var name. */
vendp = vnamep;

/* now find the end of the define/list name */
while (1) {
++vendp;
if (*vendp == ' ')
	break;
}
*vendp = '\0';

/*
* Check list name is not an existing mg function.
*/
if (name_function(vnamep) != NULL((void *)0))
return(dobeep_msgs("Variable/function name clash:", vnamep));

if (!SLIST_EMPTY(&varhead)(((&varhead)->slh_first) == ((void *)0))) {
SLIST_FOREACH_SAFE(v1, &varhead, entry, vt)for ((v1) = ((&varhead)->slh_first); (v1) && (
(vt) = ((v1)->entry.sle_next), 1); (v1) = (vt)) {
	if (strcmp(vnamep, v1->v_name) == 0)
		SLIST_REMOVE(&varhead, v1, varentry, entry)do { if ((&varhead)->slh_first == (v1)) { do { ((&
varhead))->slh_first = ((&varhead))->slh_first->
entry.sle_next; } while (0); } else { struct varentry *curelm
 = (&varhead)->slh_first; while (curelm->entry.sle_next
 != (v1)) curelm = curelm->entry.sle_next; curelm->entry
.sle_next = curelm->entry.sle_next->entry.sle_next; } ;
 } while (0);
}
}
if ((v1 = malloc(sizeof(struct varentry))) == NULL((void *)0))
return (ABORT2);
SLIST_INSERT_HEAD(&varhead, v1, entry)do { (v1)->entry.sle_next = (&varhead)->slh_first; (
&varhead)->slh_first = (v1); } while (0);
if ((v1->v_name = strndup(vnamep, BUFSIZE128)) == NULL((void *)0))
return(dobeep_msg("strndup error"));
vnamep = v1->v_name;
v1->v_count = 0;
v1->v_vals = NULL((void *)0);
v1->v_buf[0] = '\0';

defnam = v1->v_buf;

if (hasval) {
valp = skipwhite(vendp + 1);

expandvals(NULL((void *)0), valp, defnam);
defnam = NULL((void *)0);
}
*vendp = ' ';	
return (TRUE1);
619}


622static int
623expandvals(char *cmdp, char *valp, char *bp)
624{
char	 excbuf[BUFSIZE128], argbuf[BUFSIZE128];
char	 contbuf[BUFSIZE128], varbuf[BUFSIZE128];
char	*argp, *endp, *p, *v, *s = " ";
char	*regs;
int	 spc, cnt;
int	 sizof, fin, inquote;

/* now find the first argument */
p = skipwhite(valp);

if (strlcpy(argbuf, p, sizeof(argbuf)) >= sizeof(argbuf))
return (dobeep_msg("strlcpy error"));
argp = argbuf;
spc = 1; /* initially fake a space so we find first argument */
fin = inquote = cnt = spc = 0;

for (p = argbuf; *p != '\0'; p++) {
if (*(p + 1) == '\0')
	fin = 1;

if (*p != ' ') {
	if (*p == '"') {
		if (inquote == 1)
			inquote = 0;	
		else
			inquote = 1;
	}
	if (spc == 1)
		argp = p;
	spc = 0;
}
if ((*p == ' ' && inquote == 0) || fin) {
	if (spc == 1)
		continue;
	/* terminate arg string */
	if (*p == ' ') {
		*p = '\0';		
	}
	endp = p + 1;
	excbuf[0] = '\0';
	varbuf[0] = '\0';
	contbuf[0] = '\0';			
	sizof = sizeof(varbuf);
	v = varbuf;
	regs = "[\"]+.*[\"]+";
     			if (doregex(regs, argp))
		;			/* found quotes */
	else if (isvar(&argp, &v, sizof)) {

		(void)(strlcat(varbuf, " ",
                                  sizof) >= sizof);

		*p = ' ';
		(void)(strlcpy(contbuf, endp,
		    sizeof(contbuf)) >= sizeof(contbuf));

		(void)(strlcat(varbuf, contbuf,
		    sizof) >= sizof);
		
		argbuf[0] = ' ';
		argbuf[1] = '\0';
		(void)(strlcat(argbuf, varbuf,
		    sizof) >= sizof);

		p = argp = argbuf;
		spc = 1;
		fin = 0;
		continue;
	} else {
		const char *errstr;

		strtonum(argp, 0, INT_MAX0x7fffffff, &errstr);
		if (errstr != NULL((void *)0))
			return (dobeep_msgs("Var not found:",
			    argp));
	}
701#ifdef  MGLOG
      mglog_misc("x|%s|%p|%d|\n", bp, defnam, BUFSIZE128);
703#endif
	if (*bp != '\0') {
		if (strlcat(bp, s, BUFSIZE128) >= BUFSIZE128)
			return (dobeep_msg("strlcat error"));
	}
	if (strlcat(bp, argp, BUFSIZE128) >= BUFSIZE128) {
		return (dobeep_msg("strlcat error"));
	}
711/*			v1->v_count++;*/
	
	if (fin)
		break;

	*p = ' ';		/* unterminate arg string */
	spc = 1;
}
}
return (TRUE1);
721}

723/*
* Finished with buffer evaluation, so clean up any vars.
* Perhaps keeps them in mg even after use,...
*/
727/*static int
728clearvars(void)
729{
struct varentry	*v1 = NULL;

while (!SLIST_EMPTY(&varhead)) {
v1 = SLIST_FIRST(&varhead);
SLIST_REMOVE_HEAD(&varhead, entry);
free(v1->v_name);
free(v1);
}
return (FALSE);
739}
740*/
741/*
* Finished with block evaluation, so clean up any expressions.
*/
744static void
745clearexp(void)
746{
struct expentry	*e1 = NULL((void *)0);

while (!TAILQ_EMPTY(&ehead)(((&ehead)->tqh_first) == ((void *)0))) {
e1 = TAILQ_FIRST(&ehead)((&ehead)->tqh_first);
TAILQ_REMOVE(&ehead, e1, eentry)do { if (((e1)->eentry.tqe_next) != ((void *)0)) (e1)->
eentry.tqe_next->eentry.tqe_prev = (e1)->eentry.tqe_prev
; else (&ehead)->tqh_last = (e1)->eentry.tqe_prev; *
(e1)->eentry.tqe_prev = (e1)->eentry.tqe_next; ; ; } while
 (0);
free(e1->fun);
free(e1);
}
return;
756}

758/*
* Cleanup before leaving.
*/
761void
762cleanup(void)
763{
defnam = NULL((void *)0);

clearexp();
767/*	clearvars();*/
768}

770/*
* Test a string against a regular expression.
*/
773static int
774doregex(char *r, char *e)
775{
regex_t  regex_buff;

if (regcomp(&regex_buff, r, REG_EXTENDED0001)) {
regfree(&regex_buff);
return(dobeep_num("Regex compilation error line:", lnm));
}
if (!regexec(&regex_buff, e, 0, NULL((void *)0), 0)) {
regfree(&regex_buff);
return(TRUE1);
}
regfree(&regex_buff);
return(FALSE0);
788}

790/*
* Display a message so it is apparent that this is the method which stopped
* execution.
*/
794static int
795exitinterpreter(char *ptr, char *dobuf, int dosiz)
796{
cleanup();
if (batch == 0)
return(dobeep_msg("Interpreter exited via exit command."));
return(FALSE0);
801}

803/*
* All code below commented out (until end of file).
*
* Need to think about how interpreter functions are done.
* Probably don't have a choice with string-append().

809static int 	 getenvironmentvariable(char *, char *, int);
810static int	 stringappend(char *, char *, int);

812typedef int	 (*PFI)(char *, char *, int);


815struct ifunmap {
PFI		 fn_funct;
const char 	*fn_name;
struct ifunmap	*fn_next;
819};
820static struct ifunmap *ifuns;

822static struct ifunmap ifunctnames[] = {
{exitinterpreter, "exit"},
{getenvironmentvariable, "get-environment-variable"},
{stringappend, "string-append"},
{NULL, NULL}
827};

829void
830ifunmap_init(void)
831{
struct ifunmap *fn;

for (fn = ifunctnames; fn->fn_name != NULL; fn++) {
fn->fn_next = ifuns;
ifuns = fn;
}
838}

840PFI
841name_ifun(const char *ifname)
842{
struct ifunmap 	*fn;

for (fn = ifuns; fn != NULL; fn = fn->fn_next) {
if (strcmp(fn->fn_name, ifname) == 0)
	return (fn->fn_funct);
}

return (NULL);
851}


854int
855dofunc(char **ifname, char **tmpbuf, int sizof)
856{
PFI 	 fnc;
char	*p, *tmp;

p = strstr(*ifname, " ");
*p = '\0';

fnc = name_ifun(*ifname);
if (fnc == NULL)
return (FALSE);

*p = ' ';

tmp = *tmpbuf;

fnc(p, tmp, sizof);

return (TRUE);
874}

876static int
877getenvironmentvariable(char *ptr, char *dobuf, int dosiz)
878{
char		*t;
char		*tmp;
const char	*q = "\"";

t = skipwhite(ptr);

if (t[0] == *q || t[strlen(t) - 1] == *q)
return (dobeep_msgs("Please remove '\"' around:", t));
if ((tmp = getenv(t)) == NULL || *tmp == '\0')
return(dobeep_msgs("Envar not found:", t));

dobuf[0] = '\0';
if (strlcat(dobuf, q, dosiz) >= dosiz)
return (dobeep_msg("strlcat error"));
if (strlcat(dobuf, tmp, dosiz) >= dosiz)
return (dobeep_msg("strlcat error"));
if (strlcat(dobuf, q, dosiz) >= dosiz)
return (dobeep_msg("strlcat error"));

return (TRUE);
899}

901static int
902stringappend(char *ptr, char *dobuf, int dosiz)
903{
char		 varbuf[BUFSIZE], funbuf[BUFSIZE];
char            *p, *f, *v, *vendp;
int		 sizof, fin = 0;

varbuf[0] = funbuf[0] = '\0';
f = funbuf;
v = varbuf;
sizof = sizeof(varbuf);
*dobuf = '\0';

p = skipwhite(ptr);

while (*p != '\0') {
vendp = p;
while (1) {
	if (*vendp == ' ') {
		break;
	} else if (*vendp == '\0') {
		fin = 1;
		break;
	}
	++vendp;
}
      	*vendp = '\0';

if (isvar(&p, &v, sizof)) {
	if (v[0] == '"' && v[strlen(v) - 1] == '"' ) {
		v[strlen(v) - 1] = '\0';
		v = v + 1;
	}
	if (strlcat(f, v, sizof) >= sizof)
		return (dobeep_msg("strlcat error"));		
} else {
	if (p[0] == '"' && p[strlen(p) - 1] == '"' ) {
		p[strlen(p) - 1] = '\0';
		p = p + 1;
	}
	if (strlcat(f, p, sizof) >= sizof)
		return (dobeep_msg("strlcat error"));		
}
if (fin)
	break;
vendp++;
if (*vendp == '\0')
	break;
p = skipwhite(vendp);
}

(void)snprintf(dobuf, dosiz, "\"%s\"", f);

return (TRUE);
955}

957Index: main.c
958===================================================================
959RCS file: /cvs/src/usr.bin/mg/main.c,v
960retrieving revision 1.89
961diff -u -p -u -p -r1.89 main.c
962--- main.c      20 Mar 2021 09:00:49 -0000      1.89
963+++ main.c      12 Apr 2021 17:58:52 -0000
964@@ -133,10 +133,12 @@ main(int argc, char **argv)
              extern void grep_init(void);
              extern void cmode_init(void);
              extern void dired_init(void);
968+               extern void ifunmap_init(void);

              dired_init();
              grep_init();
              cmode_init();
973+               ifunmap_init();
      }


977*/