Import sources from 2011-03-30 iso image

1 files changed, 295 insertions, 0 deletions

diff --git a/sys/src/ape/cmd/expr/expr.y b/sys/src/ape/cmd/expr/expr.y
new file mode 100755
index 000000000..88237757c
--- /dev/null
+++ b/sys/src/ape/cmd/expr/expr.y
@@ -0,0 +1,295 @@
+/* Yacc productions for "expr" command: */
+
+%token OR AND ADD SUBT MULT DIV REM EQ GT GEQ LT LEQ NEQ
+%token A_STRING SUBSTR LENGTH INDEX NOARG MATCH
+
+/* operators listed below in increasing precedence: */
+%left OR
+%left AND
+%left EQ LT GT GEQ LEQ NEQ
+%left ADD SUBT
+%left MULT DIV REM
+%left MCH
+%left MATCH
+%left SUBSTR
+%left LENGTH INDEX
+
+%{
+#define YYSTYPE charp
+
+typedef char *charp;
+%}
+
+%%
+
+/* a single `expression' is evaluated and printed: */
+
+expression:	expr NOARG = {
+			prt(1, $1);
+			exit((!strcmp($1,"0")||!strcmp($1,"\0"))? 1: 0);
+			}
+	;
+
+
+expr:	'(' expr ')' = { $$ = $2; }
+	| expr OR expr   = { $$ = conj(OR, $1, $3); }
+	| expr AND expr   = { $$ = conj(AND, $1, $3); }
+	| expr EQ expr   = { $$ = rel(EQ, $1, $3); }
+	| expr GT expr   = { $$ = rel(GT, $1, $3); }
+	| expr GEQ expr   = { $$ = rel(GEQ, $1, $3); }
+	| expr LT expr   = { $$ = rel(LT, $1, $3); }
+	| expr LEQ expr   = { $$ = rel(LEQ, $1, $3); }
+	| expr NEQ expr   = { $$ = rel(NEQ, $1, $3); }
+	| expr ADD expr   = { $$ = arith(ADD, $1, $3); }
+	| expr SUBT expr   = { $$ = arith(SUBT, $1, $3); }
+	| expr MULT expr   = { $$ = arith(MULT, $1, $3); }
+	| expr DIV expr   = { $$ = arith(DIV, $1, $3); }
+	| expr REM expr   = { $$ = arith(REM, $1, $3); }
+	| expr MCH expr	 = { $$ = match($1, $3); }
+	| MATCH expr expr = { $$ = match($2, $3); }
+	| SUBSTR expr expr expr = { $$ = substr($2, $3, $4); }
+	| LENGTH expr       = { $$ = length($2); }
+	| INDEX expr expr = { $$ = index($2, $3); }
+	| A_STRING
+	;
+%%
+/*	expression command */
+#include <stdio.h>
+/* get rid of yacc debug printf's */
+#define printf
+#define ESIZE	512
+#define error(c)	errxx(c)
+#define EQL(x,y) !strcmp(x,y)
+long atol();
+char *ltoa();
+char	**Av;
+int	Ac;
+int	Argi;
+
+char Mstring[1][128];
+char *malloc();
+extern int nbra;
+int yyparse(void);
+
+main(argc, argv) char **argv; {
+	Ac = argc;
+	Argi = 1;
+	Av = argv;
+	yyparse();
+}
+
+char *operator[] = { "|", "&", "+", "-", "*", "/", "%", ":",
+	"=", "==", "<", "<=", ">", ">=", "!=",
+	"match", "substr", "length", "index", "\0" };
+int op[] = { OR, AND, ADD,  SUBT, MULT, DIV, REM, MCH,
+	EQ, EQ, LT, LEQ, GT, GEQ, NEQ,
+	MATCH, SUBSTR, LENGTH, INDEX };
+yylex() {
+	register char *p;
+	register i;
+
+	if(Argi >= Ac) return NOARG;
+
+	p = Av[Argi++];
+
+	if(*p == '(' || *p == ')')
+		return (int)*p;
+	for(i = 0; *operator[i]; ++i)
+		if(EQL(operator[i], p))
+			return op[i];
+
+	yylval = p;
+	return A_STRING;
+}
+
+char *rel(op, r1, r2) register char *r1, *r2; {
+	register i;
+
+	if(ematch(r1, "-\\{0,1\\}[0-9]*$") && ematch(r2, "-\\{0,1\\}[0-9]*$"))
+		i = atol(r1) - atol(r2);
+	else
+		i = strcmp(r1, r2);
+	switch(op) {
+	case EQ: i = i==0; break;
+	case GT: i = i>0; break;
+	case GEQ: i = i>=0; break;
+	case LT: i = i<0; break;
+	case LEQ: i = i<=0; break;
+	case NEQ: i = i!=0; break;
+	}
+	return i? "1": "0";
+}
+
+char *arith(op, r1, r2) char *r1, *r2; {
+	long i1, i2;
+	register char *rv;
+
+	if(!(ematch(r1, "-\\{0,1\\}[0-9]*$") && ematch(r2, "-\\{0,1\\}[0-9]*$")))
+		yyerror("non-numeric argument");
+	i1 = atol(r1);
+	i2 = atol(r2);
+
+	switch(op) {
+	case ADD: i1 = i1 + i2; break;
+	case SUBT: i1 = i1 - i2; break;
+	case MULT: i1 = i1 * i2; break;
+	case DIV: i1 = i1 / i2; break;
+	case REM: i1 = i1 % i2; break;
+	}
+	rv = malloc(16);
+	strcpy(rv, ltoa(i1));
+	return rv;
+}
+char *conj(op, r1, r2) char *r1, *r2; {
+	register char *rv;
+
+	switch(op) {
+
+	case OR:
+		if(EQL(r1, "0")
+		|| EQL(r1, ""))
+			if(EQL(r2, "0")
+			|| EQL(r2, ""))
+				rv = "0";
+			else
+				rv = r2;
+		else
+			rv = r1;
+		break;
+	case AND:
+		if(EQL(r1, "0")
+		|| EQL(r1, ""))
+			rv = "0";
+		else if(EQL(r2, "0")
+		|| EQL(r2, ""))
+			rv = "0";
+		else
+			rv = r1;
+		break;
+	}
+	return rv;
+}
+
+char *substr(v, s, w) char *v, *s, *w; {
+register si, wi;
+register char *res;
+
+	si = atol(s);
+	wi = atol(w);
+	while(--si) if(*v) ++v;
+
+	res = v;
+
+	while(wi--) if(*v) ++v;
+
+	*v = '\0';
+	return res;
+}
+
+char *length(s) register char *s; {
+	register i = 0;
+	register char *rv;
+
+	while(*s++) ++i;
+
+	rv = malloc(8);
+	strcpy(rv, ltoa((long)i));
+	return rv;
+}
+
+char *index(s, t) char *s, *t; {
+	register i, j;
+	register char *rv;
+
+	for(i = 0; s[i] ; ++i)
+		for(j = 0; t[j] ; ++j)
+			if(s[i]==t[j]) {
+				strcpy(rv=malloc(8), ltoa((long)++i));
+				return rv;
+			}
+	return "0";
+}
+
+char *match(s, p)
+{
+	register char *rv;
+
+	strcpy(rv=malloc(8), ltoa((long)ematch(s, p)));
+	if(nbra) {
+		rv = malloc(strlen(Mstring[0])+1);
+		strcpy(rv, Mstring[0]);
+	}
+	return rv;
+}
+
+#define INIT	register char *sp = instring;
+#define GETC()		(*sp++)
+#define PEEKC()		(*sp)
+#define UNGETC(c)	(--sp)
+#define RETURN(c)	return
+#define ERROR(c)	errxx(c)
+
+
+ematch(s, p)
+char *s;
+register char *p;
+{
+	static char expbuf[ESIZE];
+	char *compile();
+	register num;
+	extern char *braslist[], *braelist[], *loc2;
+
+	compile(p, expbuf, &expbuf[ESIZE], 0);
+	if(nbra > 1)
+		yyerror("Too many '\\('s");
+	if(advance(s, expbuf)) {
+		if(nbra == 1) {
+			p = braslist[0];
+			num = braelist[0] - p;
+			strncpy(Mstring[0], p, num);
+			Mstring[0][num] = '\0';
+		}
+		return(loc2-s);
+	}
+	return(0);
+}
+
+errxx(c)
+{
+	yyerror("RE error");
+}
+
+#include  "regexp.h"
+yyerror(s)
+
+{
+	write(2, "expr: ", 6);
+	prt(2, s);
+	exit(2);
+}
+prt(fd, s)
+char *s;
+{
+	write(fd, s, strlen(s));
+	write(fd, "\n", 1);
+}
+char *ltoa(l)
+long l;
+{
+	static char str[20];
+	register char *sp = &str[18];
+	register i;
+	register neg = 0;
+
+	if(l < 0)
+		++neg, l *= -1;
+	str[19] = '\0';
+	do {
+		i = l % 10;
+		*sp-- = '0' + i;
+		l /= 10;
+	} while(l);
+	if(neg)
+		*sp-- = '-';
+	return ++sp;
+}