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freebsd/bin/expr/expr.y
Joerg Wunsch 2a353a9fb4 expr(1) didn't comply to Posix.2 and its own man page: any
comparisions have been made as string comparisions, even in cases
where both operands clearly qualified as integers.

The fix is to make the parser properly analyzing whether an operand is
a valid integer or not.
1995-08-04 17:08:07 +00:00

548 lines
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%{
/* Written by Pace Willisson (pace@blitz.com)
* and placed in the public domain.
*
* Largely rewritten by J.T. Conklin (jtc@wimsey.com)
*
* $Id: expr.y,v 1.9 1995/03/19 13:28:41 joerg Exp $
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <locale.h>
#include <ctype.h>
#include <err.h>
enum valtype {
integer, string
} ;
struct val {
enum valtype type;
union {
char *s;
int i;
} u;
} ;
struct val *result;
struct val *op_or ();
struct val *op_and ();
struct val *op_eq ();
struct val *op_gt ();
struct val *op_lt ();
struct val *op_ge ();
struct val *op_le ();
struct val *op_ne ();
struct val *op_plus ();
struct val *op_minus ();
struct val *op_times ();
struct val *op_div ();
struct val *op_rem ();
struct val *op_colon ();
char **av;
%}
%union
{
struct val *val;
}
%left <val> '|'
%left <val> '&'
%left <val> '=' '>' '<' GE LE NE
%left <val> '+' '-'
%left <val> '*' '/' '%'
%left <val> ':'
%left UNARY
%token <val> TOKEN
%type <val> start expr
%%
start: expr { result = $$; }
expr: TOKEN
| '(' expr ')' { $$ = $2; }
| expr '|' expr { $$ = op_or ($1, $3); }
| expr '&' expr { $$ = op_and ($1, $3); }
| expr '=' expr { $$ = op_eq ($1, $3); }
| expr '>' expr { $$ = op_gt ($1, $3); }
| expr '<' expr { $$ = op_lt ($1, $3); }
| expr GE expr { $$ = op_ge ($1, $3); }
| expr LE expr { $$ = op_le ($1, $3); }
| expr NE expr { $$ = op_ne ($1, $3); }
| expr '+' expr { $$ = op_plus ($1, $3); }
| expr '-' expr { $$ = op_minus ($1, $3); }
| expr '*' expr { $$ = op_times ($1, $3); }
| expr '/' expr { $$ = op_div ($1, $3); }
| expr '%' expr { $$ = op_rem ($1, $3); }
| expr ':' expr { $$ = op_colon ($1, $3); }
;
%%
struct val *
make_integer (i)
int i;
{
struct val *vp;
vp = (struct val *) malloc (sizeof (*vp));
if (vp == NULL) {
err (2, NULL);
}
vp->type = integer;
vp->u.i = i;
return vp;
}
struct val *
make_str (s)
char *s;
{
struct val *vp;
int i, isint;
vp = (struct val *) malloc (sizeof (*vp));
if (vp == NULL || ((vp->u.s = strdup (s)) == NULL)) {
err (2, NULL);
}
for(i = 1, isint = isdigit(s[0]) || s[0] == '-';
isint && i < strlen(s);
i++)
{
if(!isdigit(s[i]))
isint = 0;
}
vp->type = string;
if(isint)
to_integer(vp);
return vp;
}
void
free_value (vp)
struct val *vp;
{
if (vp->type == string)
free (vp->u.s);
}
int
to_integer (vp)
struct val *vp;
{
char *s;
int neg;
int i;
if (vp->type == integer)
return 1;
s = vp->u.s;
i = 0;
neg = (*s == '-');
if (neg)
s++;
for (;*s; s++) {
if (!isdigit (*s))
return 0;
i *= 10;
i += *s - '0';
}
free (vp->u.s);
if (neg)
i *= -1;
vp->type = integer;
vp->u.i = i;
return 1;
}
void
to_string (vp)
struct val *vp;
{
char *tmp;
if (vp->type == string)
return;
tmp = malloc (25);
if (tmp == NULL) {
err (2, NULL);
}
sprintf (tmp, "%d", vp->u.i);
vp->type = string;
vp->u.s = tmp;
}
int
isstring (vp)
struct val *vp;
{
return (vp->type == string);
}
int
yylex ()
{
char *p;
if (*av == NULL)
return (0);
p = *av++;
if (strlen (p) == 1) {
if (strchr ("|&=<>+-*/%:()", *p))
return (*p);
} else if (strlen (p) == 2 && p[1] == '=') {
switch (*p) {
case '>': return (GE);
case '<': return (LE);
case '!': return (NE);
}
}
yylval.val = make_str (p);
return (TOKEN);
}
int
is_zero_or_null (vp)
struct val *vp;
{
if (vp->type == integer) {
return (vp->u.i == 0);
} else {
return (*vp->u.s == 0 || (to_integer (vp) && vp->u.i == 0));
}
/* NOTREACHED */
}
int yyparse ();
void
main (argc, argv)
int argc;
char **argv;
{
setlocale (LC_ALL, "");
av = argv + 1;
yyparse ();
if (result->type == integer)
printf ("%d\n", result->u.i);
else
printf ("%s\n", result->u.s);
exit (is_zero_or_null (result));
}
int
yyerror (s)
char *s;
{
errx (2, "syntax error");
}
struct val *
op_or (a, b)
struct val *a, *b;
{
if (is_zero_or_null (a)) {
free_value (a);
return (b);
} else {
free_value (b);
return (a);
}
}
struct val *
op_and (a, b)
struct val *a, *b;
{
if (is_zero_or_null (a) || is_zero_or_null (b)) {
free_value (a);
free_value (b);
return (make_integer (0));
} else {
free_value (b);
return (a);
}
}
struct val *
op_eq (a, b)
struct val *a, *b;
{
struct val *r;
if (isstring (a) || isstring (b)) {
to_string (a);
to_string (b);
r = make_integer (strcoll (a->u.s, b->u.s) == 0);
} else {
r = make_integer (a->u.i == b->u.i);
}
free_value (a);
free_value (b);
return r;
}
struct val *
op_gt (a, b)
struct val *a, *b;
{
struct val *r;
if (isstring (a) || isstring (b)) {
to_string (a);
to_string (b);
r = make_integer (strcoll (a->u.s, b->u.s) > 0);
} else {
r= make_integer (a->u.i > b->u.i);
}
free_value (a);
free_value (b);
return r;
}
struct val *
op_lt (a, b)
struct val *a, *b;
{
struct val *r;
if (isstring (a) || isstring (b)) {
to_string (a);
to_string (b);
r = make_integer (strcoll (a->u.s, b->u.s) < 0);
} else {
r = make_integer (a->u.i < b->u.i);
}
free_value (a);
free_value (b);
return r;
}
struct val *
op_ge (a, b)
struct val *a, *b;
{
struct val *r;
if (isstring (a) || isstring (b)) {
to_string (a);
to_string (b);
r = make_integer (strcoll (a->u.s, b->u.s) >= 0);
} else {
r = make_integer (a->u.i >= b->u.i);
}
free_value (a);
free_value (b);
return r;
}
struct val *
op_le (a, b)
struct val *a, *b;
{
struct val *r;
if (isstring (a) || isstring (b)) {
to_string (a);
to_string (b);
r = make_integer (strcoll (a->u.s, b->u.s) <= 0);
} else {
r = make_integer (a->u.i <= b->u.i);
}
free_value (a);
free_value (b);
return r;
}
struct val *
op_ne (a, b)
struct val *a, *b;
{
struct val *r;
if (isstring (a) || isstring (b)) {
to_string (a);
to_string (b);
r = make_integer (strcoll (a->u.s, b->u.s) != 0);
} else {
r = make_integer (a->u.i != b->u.i);
}
free_value (a);
free_value (b);
return r;
}
struct val *
op_plus (a, b)
struct val *a, *b;
{
struct val *r;
if (!to_integer (a) || !to_integer (b)) {
errx (2, "non-numeric argument");
}
r = make_integer (a->u.i + b->u.i);
free_value (a);
free_value (b);
return r;
}
struct val *
op_minus (a, b)
struct val *a, *b;
{
struct val *r;
if (!to_integer (a) || !to_integer (b)) {
errx (2, "non-numeric argument");
}
r = make_integer (a->u.i - b->u.i);
free_value (a);
free_value (b);
return r;
}
struct val *
op_times (a, b)
struct val *a, *b;
{
struct val *r;
if (!to_integer (a) || !to_integer (b)) {
errx (2, "non-numeric argument");
}
r = make_integer (a->u.i * b->u.i);
free_value (a);
free_value (b);
return (r);
}
struct val *
op_div (a, b)
struct val *a, *b;
{
struct val *r;
if (!to_integer (a) || !to_integer (b)) {
errx (2, "non-numeric argument");
}
if (b->u.i == 0) {
errx (2, "division by zero");
}
r = make_integer (a->u.i / b->u.i);
free_value (a);
free_value (b);
return r;
}
struct val *
op_rem (a, b)
struct val *a, *b;
{
struct val *r;
if (!to_integer (a) || !to_integer (b)) {
errx (2, "non-numeric argument");
}
if (b->u.i == 0) {
errx (2, "division by zero");
}
r = make_integer (a->u.i % b->u.i);
free_value (a);
free_value (b);
return r;
}
#include <sys/types.h>
#include <regex.h>
struct val *
op_colon (a, b)
struct val *a, *b;
{
regex_t rp;
regmatch_t rm[2];
char errbuf[256];
int eval;
struct val *v;
/* coerce to both arguments to strings */
to_string(a);
to_string(b);
/* compile regular expression */
if ((eval = regcomp (&rp, b->u.s, 0)) != 0) {
regerror (eval, &rp, errbuf, sizeof(errbuf));
errx (2, "%s", errbuf);
}
/* compare string against pattern */
/* remember that patterns are anchored to the beginning of the line */
if (regexec(&rp, a->u.s, 2, rm, 0) == 0 && rm[0].rm_so == 0) {
if (rm[1].rm_so >= 0) {
*(a->u.s + rm[1].rm_eo) = '\0';
v = make_str (a->u.s + rm[1].rm_so);
} else {
v = make_integer (rm[0].rm_eo - rm[0].rm_so);
}
} else {
if (rp.re_nsub == 0) {
v = make_integer (0);
} else {
v = make_str ("");
}
}
/* free arguments and pattern buffer */
free_value (a);
free_value (b);
regfree (&rp);
return v;
}