freebsd-src/bin/expr/expr.y
1999-08-27 23:15:48 +00:00

546 lines
8.3 KiB
Plaintext

%{
/* Written by Pace Willisson (pace@blitz.com)
* and placed in the public domain.
*
* Largely rewritten by J.T. Conklin (jtc@wimsey.com)
*
* $FreeBSD$
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <locale.h>
#include <ctype.h>
#include <err.h>
enum valtype {
integer, numeric_string, 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> ':'
%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) {
errx (2, "malloc() failed");
}
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)) {
errx (2, "malloc() failed");
}
for(i = 1, isint = isdigit(s[0]) || s[0] == '-';
isint && i < strlen(s);
i++)
{
if(!isdigit(s[i]))
isint = 0;
}
if (isint)
vp->type = numeric_string;
else
vp->type = string;
return vp;
}
void
free_value (vp)
struct val *vp;
{
if (vp->type == string || vp->type == numeric_string)
free (vp->u.s);
}
int
to_integer (vp)
struct val *vp;
{
int i;
if (vp->type == integer)
return 1;
if (vp->type == string)
return 0;
/* vp->type == numeric_string, make it numeric */
i = atoi(vp->u.s);
free (vp->u.s);
vp->u.i = i;
vp->type = integer;
return 1;
}
void
to_string (vp)
struct val *vp;
{
char *tmp;
if (vp->type == string || vp->type == numeric_string)
return;
tmp = malloc (25);
if (tmp == NULL) {
errx (2, "malloc() failed");
}
sprintf (tmp, "%d", vp->u.i);
vp->type = string;
vp->u.s = tmp;
}
int
isstring (vp)
struct val *vp;
{
/* only TRUE if this string is not a valid integer */
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 ();
int
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);
return (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 {
(void)to_integer(a);
(void)to_integer(b);
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 {
(void)to_integer(a);
(void)to_integer(b);
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 {
(void)to_integer(a);
(void)to_integer(b);
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 {
(void)to_integer(a);
(void)to_integer(b);
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 {
(void)to_integer(a);
(void)to_integer(b);
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 {
(void)to_integer(a);
(void)to_integer(b);
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;
}