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|
%token ARITH_OR ARITH_AND ARITH_ADD ARITH_SUBT ARITH_MULT ARITH_DIV ARITH_REM ARITH_EQ ARITH_GT ARITH_GEQ ARITH_LT ARITH_LEQ ARITH_NEQ
%token ARITH_NUM ARITH_LPAREN ARITH_RPAREN ARITH_NOT ARITH_UNARYMINUS
%left ARITH_OR
%left ARITH_AND
%left ARITH_EQ ARITH_NEQ
%left ARITH_LT ARITH_GT ARITH_GEQ ARITH_LEQ
%left ARITH_ADD ARITH_SUBT
%left ARITH_MULT ARITH_DIV ARITH_REM
%left ARITH_UNARYMINUS ARITH_NOT
%%
exp: expr = {
return ($1);
}
;
expr: ARITH_LPAREN expr ARITH_RPAREN = { $$ = $2; }
| expr ARITH_OR expr = { $$ = $1 ? $1 : $3 ? $3 : 0; }
| expr ARITH_AND expr = { $$ = $1 ? ( $3 ? $3 : 0 ) : 0; }
| expr ARITH_EQ expr = { $$ = $1 == $3; }
| expr ARITH_GT expr = { $$ = $1 > $3; }
| expr ARITH_GEQ expr = { $$ = $1 >= $3; }
| expr ARITH_LT expr = { $$ = $1 < $3; }
| expr ARITH_LEQ expr = { $$ = $1 <= $3; }
| expr ARITH_NEQ expr = { $$ = $1 != $3; }
| expr ARITH_ADD expr = { $$ = $1 + $3; }
| expr ARITH_SUBT expr = { $$ = $1 - $3; }
| expr ARITH_MULT expr = { $$ = $1 * $3; }
| expr ARITH_DIV expr = {
if ($3 == 0)
yyerror("division by zero");
$$ = $1 / $3;
}
| expr ARITH_REM expr = { $$ = $1 % $3; }
| ARITH_NOT expr = { $$ = !($2); }
| ARITH_UNARYMINUS expr = { $$ = -($2); }
| ARITH_NUM
;
%%
/*-
* Copyright (c) 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Kenneth Almquist.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#ifndef lint
static char sccsid[] = "@(#)arith.y 8.1 (Berkeley) 5/31/93";
#endif /* not lint */
#include "shell.h"
#include "error.h"
#include "output.h"
#include "memalloc.h"
char *arith_buf, *arith_startbuf;
arith(s)
char *s;
{
extern arith_wasoper;
long result;
arith_wasoper = 1;
arith_buf = arith_startbuf = s;
INTOFF;
result = yyparse();
arith_lex_reset(); /* reprime lex */
INTON;
return (result);
}
yyerror(s)
char *s;
{
extern yytext, yylval;
yyerrok;
yyclearin;
arith_lex_reset(); /* reprime lex */
error("arithmetic expression: %s: \"%s\"", s, arith_startbuf);
}
/*
* The exp(1) builtin.
*/
expcmd(argc, argv)
char **argv;
{
char *p;
char *concat;
char **ap;
long i;
if (argc > 1) {
p = argv[1];
if (argc > 2) {
/*
* concatenate arguments
*/
STARTSTACKSTR(concat);
ap = argv + 2;
for (;;) {
while (*p)
STPUTC(*p++, concat);
if ((p = *ap++) == NULL)
break;
STPUTC(' ', concat);
}
STPUTC('\0', concat);
p = grabstackstr(concat);
}
} else
p = "";
i = arith(p);
out1fmt("%d\n", i);
return (! i);
}
/*************************/
#ifdef TEST_ARITH
#include <stdio.h>
main(argc, argv)
char *argv[];
{
printf("%d\n", exp(argv[1]));
}
error(s)
char *s;
{
fprintf(stderr, "exp: %s\n", s);
exit(1);
}
#endif
|
