581 lines
9.3 KiB
Plaintext
581 lines
9.3 KiB
Plaintext
%{
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/* Written by Pace Willisson (pace@blitz.com)
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* and placed in the public domain
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*
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* $Header: /cvsroot/src/bin/expr/expr.y,v 1.6 1993/06/14 19:59:07 jtc Exp $
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*/
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <ctype.h>
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enum valtype {
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integer, string
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} ;
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struct val {
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enum valtype type;
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union {
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char *s;
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int i;
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} u;
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} ;
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struct val *result;
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struct val *op_or ();
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struct val *op_and ();
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struct val *op_eq ();
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struct val *op_gt ();
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struct val *op_lt ();
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struct val *op_ge ();
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struct val *op_le ();
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struct val *op_ne ();
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struct val *op_plus ();
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struct val *op_minus ();
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struct val *op_times ();
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struct val *op_div ();
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struct val *op_rem ();
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struct val *op_colon ();
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char **av;
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%}
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%union
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{
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struct val *val;
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}
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%left <val> '|'
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%left <val> '&'
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%left <val> '=' '>' '<' GE LE NE
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%left <val> '+' '-'
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%left <val> '*' '/' '%'
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%left <val> ':'
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%left UNARY
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%token <val> TOKEN
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%type <val> start expr
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%%
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start: expr { result = $$; }
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expr: TOKEN
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| '(' expr ')' { $$ = $2; }
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| expr '|' expr { $$ = op_or ($1, $3); }
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| expr '&' expr { $$ = op_and ($1, $3); }
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| expr '=' expr { $$ = op_eq ($1, $3); }
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| expr '>' expr { $$ = op_gt ($1, $3); }
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| expr '<' expr { $$ = op_lt ($1, $3); }
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| expr GE expr { $$ = op_ge ($1, $3); }
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| expr LE expr { $$ = op_le ($1, $3); }
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| expr NE expr { $$ = op_ne ($1, $3); }
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| expr '+' expr { $$ = op_plus ($1, $3); }
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| expr '-' expr { $$ = op_minus ($1, $3); }
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| expr '*' expr { $$ = op_times ($1, $3); }
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| expr '/' expr { $$ = op_div ($1, $3); }
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| expr '%' expr { $$ = op_rem ($1, $3); }
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| expr ':' expr { $$ = op_colon ($1, $3); }
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| '-' expr %prec UNARY { $$ = op_minus (NULL, $2); }
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;
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%%
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struct val *
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make_integer (i)
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int i;
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{
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struct val *vp;
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vp = (struct val *) malloc (sizeof (*vp));
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if (vp == NULL) {
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fprintf (stderr, "expr: out of memory\n");
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exit (2);
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}
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vp->type = integer;
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vp->u.i = i;
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return vp;
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}
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struct val *
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make_str (s)
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char *s;
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{
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struct val *vp;
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vp = (struct val *) malloc (sizeof (*vp));
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if (vp == NULL || ((vp->u.s = strdup (s)) == NULL)) {
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fprintf (stderr, "expr: out of memory\n");
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exit (2);
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}
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vp->type = string;
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return vp;
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}
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void
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free_value (vp)
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struct val *vp;
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{
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if (vp->type == string)
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free (vp->u.s);
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}
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int
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to_integer (vp)
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struct val *vp;
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{
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char *s;
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int neg;
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int i;
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if (vp->type == integer)
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return 1;
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s = vp->u.s;
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i = 0;
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neg = (*s == '-');
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if (neg)
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s++;
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for (;*s; s++) {
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if (!isdigit (*s))
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return 0;
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i *= 10;
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i += *s - '0';
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}
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free (vp->u.s);
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if (neg)
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i *= -1;
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vp->type = integer;
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vp->u.i = i;
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return 1;
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}
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void
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to_string (vp)
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struct val *vp;
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{
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char *tmp;
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if (vp->type == string)
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return;
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tmp = malloc (25);
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if (tmp == NULL) {
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fprintf (stderr, "expr: out of memory\n");
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exit (2);
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}
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sprintf (tmp, "%d", vp->u.i);
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vp->type = string;
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vp->u.s = tmp;
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}
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int
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isstring (vp)
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struct val *vp;
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{
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return (vp->type == string);
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}
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int
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yylex ()
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{
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struct val *vp;
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char *p;
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if (*av == NULL)
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return (0);
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p = *av++;
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if (strlen (p) == 1) {
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if (strchr ("|&=<>+-*/%:()", *p))
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return (*p);
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} else if (strlen (p) == 2 && p[1] == '=') {
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switch (*p) {
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case '>': return (GE);
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case '<': return (LE);
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case '!': return (NE);
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}
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}
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yylval.val = make_str (p);
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return (TOKEN);
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}
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int
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is_zero_or_null (vp)
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struct val *vp;
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{
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/* Like most other versions of expr, this version will return
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false for a string value of multiple zeros.*/
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if (vp->type == integer) {
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return (vp->u.i == 0);
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} else {
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return (*vp->u.s == 0 || strcmp (vp->u.s, "0") == 0);
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}
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/* NOTREACHED */
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}
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void
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main (argc, argv)
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int argc;
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char **argv;
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{
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av = argv + 1;
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yyparse ();
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if (result->type == integer)
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printf ("%d\n", result->u.i);
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else
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printf ("%s\n", result->u.s);
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if (is_zero_or_null (result))
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exit (1);
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else
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exit (0);
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}
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int
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yyerror (s)
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char *s;
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{
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fprintf (stderr, "expr: syntax error\n");
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exit (2);
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}
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struct val *
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op_or (a, b)
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struct val *a, *b;
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{
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if (is_zero_or_null (a)) {
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free_value (a);
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return (b);
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} else {
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free_value (b);
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return (a);
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}
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}
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struct val *
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op_and (a, b)
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struct val *a, *b;
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{
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if (is_zero_or_null (a) || is_zero_or_null (b)) {
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free_value (a);
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free_value (b);
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return (make_integer (0));
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} else {
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free_value (b);
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return (a);
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}
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}
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struct val *
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op_eq (a, b)
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struct val *a, *b;
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{
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struct val *r;
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/* attempt to coerce both arguments to integers */
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(void) to_integer (a);
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(void) to_integer (b);
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/* But if either one of them really is a string, do
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a string comparison */
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if (isstring (a) || isstring (b)) {
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to_string (a);
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to_string (b);
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r = make_integer (strcmp (a->u.s, b->u.s) == 0);
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} else {
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r = make_integer (a->u.i == b->u.i);
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}
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free_value (a);
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free_value (b);
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return r;
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}
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struct val *
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op_gt (a, b)
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struct val *a, *b;
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{
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struct val *r;
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/* attempt to coerce both arguments to integers */
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(void) to_integer (a);
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(void) to_integer (b);
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/* But if either one of them really is a string, do
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a string comparison */
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if (isstring (a) || isstring (b)) {
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to_string (a);
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to_string (b);
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r = make_integer (strcmp (a->u.s, b->u.s) > 0);
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} else {
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r= make_integer (a->u.i > b->u.i);
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}
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free_value (a);
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free_value (b);
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return r;
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}
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struct val *
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op_lt (a, b)
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struct val *a, *b;
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{
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struct val *r;
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/* attempt to coerce both arguments to integers */
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(void) to_integer (a);
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(void) to_integer (b);
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/* But if either one of them really is a string, do
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a string comparison */
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if (isstring (a) || isstring (b)) {
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to_string (a);
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to_string (b);
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r = make_integer (strcmp (a->u.s, b->u.s) < 0);
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} else {
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r = make_integer (a->u.i < b->u.i);
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}
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free_value (a);
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free_value (b);
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return r;
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}
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struct val *
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op_ge (a, b)
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struct val *a, *b;
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{
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struct val *r;
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/* attempt to coerce both arguments to integers */
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(void) to_integer (a);
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(void) to_integer (b);
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/* But if either one of them really is a string, do
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a string comparison */
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if (isstring (a) || isstring (b)) {
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to_string (a);
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to_string (b);
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r = make_integer (strcmp (a->u.s, b->u.s) >= 0);
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} else {
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r = make_integer (a->u.i >= b->u.i);
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}
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free_value (a);
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free_value (b);
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return r;
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}
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struct val *
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op_le (a, b)
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struct val *a, *b;
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{
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struct val *r;
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/* attempt to coerce both arguments to integers */
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(void) to_integer (a);
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(void) to_integer (b);
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/* But if either one of them really is a string, do
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a string comparison */
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if (isstring (a) || isstring (b)) {
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to_string (a);
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to_string (b);
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r = make_integer (strcmp (a->u.s, b->u.s) <= 0);
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} else {
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r = make_integer (a->u.i <= b->u.i);
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}
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free_value (a);
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free_value (b);
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return r;
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}
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struct val *
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op_ne (a, b)
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struct val *a, *b;
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{
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struct val *r;
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/* attempt to coerce both arguments to integers */
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(void) to_integer (a);
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(void) to_integer (b);
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/* But if either one of them really is a string, do
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a string comparison */
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if (isstring (a) || isstring (b)) {
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to_string (a);
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to_string (b);
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r = make_integer (strcmp (a->u.s, b->u.s) != 0);
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} else {
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r = make_integer (a->u.i != b->u.i);
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}
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free_value (a);
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free_value (b);
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return r;
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}
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struct val *
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op_plus (a, b)
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struct val *a, *b;
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{
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struct val *r;
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if (!to_integer (a) || !to_integer (b)) {
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fprintf (stderr, "expr: non-numeric argument\n");
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exit (2);
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}
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r = make_integer (a->u.i + b->u.i);
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free_value (a);
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free_value (b);
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return r;
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}
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struct val *
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op_minus (a, b)
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struct val *a, *b;
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{
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struct val *r;
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if (!to_integer (a) || !to_integer (b)) {
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fprintf (stderr, "expr: non-numeric argument\n");
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exit (2);
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}
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r = make_integer (a->u.i - b->u.i);
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free_value (a);
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free_value (b);
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return r;
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}
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struct val *
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op_times (a, b)
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struct val *a, *b;
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{
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struct val *r;
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if (!to_integer (a) || !to_integer (b)) {
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fprintf (stderr, "expr: non-numeric argument\n");
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exit (2);
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}
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r = make_integer (a->u.i * b->u.i);
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free_value (a);
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free_value (b);
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return (r);
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}
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struct val *
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op_div (a, b)
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struct val *a, *b;
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{
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struct val *r;
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if (!to_integer (a) || !to_integer (b)) {
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fprintf (stderr, "expr: non-numeric argument\n");
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exit (2);
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}
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if (b->u.i == 0) {
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fprintf (stderr, "expr: division by zero\n");
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exit (2);
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}
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r = make_integer (a->u.i / b->u.i);
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free_value (a);
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free_value (b);
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return r;
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}
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struct val *
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op_rem (a, b)
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struct val *a, *b;
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{
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struct val *r;
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if (!to_integer (a) || !to_integer (b)) {
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fprintf (stderr, "expr: non-numeric argument\n");
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exit (2);
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}
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if (b->u.i == 0) {
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fprintf (stderr, "expr: division by zero\n");
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exit (2);
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}
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r = make_integer (a->u.i % b->u.i);
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free_value (a);
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free_value (b);
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return r;
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}
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#include <regex.h>
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#define SE_MAX 30
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struct val *
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op_colon (a, b)
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struct val *a, *b;
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{
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regex_t rp;
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regmatch_t rm[SE_MAX];
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char errbuf[256];
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int eval;
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char *newpat;
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struct val *v;
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/* patterns are anchored to the beginning of the line */
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newpat = malloc (strlen (b->u.s) + 2);
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strcpy (newpat, "^");
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strcat (newpat, b->u.s);
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/* compile regular expression */
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if ((eval = regcomp (&rp, newpat, 0)) != 0) {
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regerror (eval, &rp, errbuf, sizeof(errbuf));
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fprintf (stderr, "expr: %s\n", errbuf);
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exit (2);
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}
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free (newpat);
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/* compare string against pattern */
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if (regexec(&rp, a->u.s, SE_MAX, rm, 0) == 0) {
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if (rm[1].rm_so >= 0) {
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*(a->u.s + rm[1].rm_eo) = 0;
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v = make_str (a->u.s + rm[1].rm_so);
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} else {
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v = make_integer (rm[0].rm_eo - rm[0].rm_so);
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}
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} else {
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v = make_integer (0);
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}
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/* free arguments and pattern buffer */
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free_value (a);
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free_value (b);
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regfree (&rp);
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return v;
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}
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