Correcting tag name to be like previous ones1_3_0

1 files changed, 505 insertions, 0 deletions

diff --git a/coreutils/expr.c b/coreutils/expr.c
new file mode 100644
index 000000000..191473446
--- /dev/null
+++ b/coreutils/expr.c
@@ -0,0 +1,505 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * Mini expr implementation for busybox
+ *
+ * based on GNU expr Mike Parker.
+ * Copyright (C) 86, 1991-1997, 1999 Free Software Foundation, Inc.
+ *
+ * Busybox modifications
+ * Copyright (c) 2000  Edward Betts <edward@debian.org>.
+ * Copyright (C) 2003-2005  Vladimir Oleynik <dzo@simtreas.ru>
+ *  - reduced 464 bytes.
+ *  - 64 math support
+ *
+ * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
+ */
+
+/* This program evaluates expressions.  Each token (operator, operand,
+ * parenthesis) of the expression must be a separate argument.  The
+ * parser used is a reasonably general one, though any incarnation of
+ * it is language-specific.  It is especially nice for expressions.
+ *
+ * No parse tree is needed; a new node is evaluated immediately.
+ * One function can handle multiple operators all of equal precedence,
+ * provided they all associate ((x op x) op x). */
+
+/* no getopt needed */
+
+#include "busybox.h"
+#include "xregex.h"
+
+/* The kinds of value we can have.  */
+enum valtype {
+	integer,
+	string
+};
+typedef enum valtype TYPE;
+
+#if ENABLE_EXPR_MATH_SUPPORT_64
+typedef int64_t arith_t;
+
+#define PF_REZ      "ll"
+#define PF_REZ_TYPE (long long)
+#define STRTOL(s, e, b) strtoll(s, e, b)
+#else
+typedef long arith_t;
+
+#define PF_REZ      "l"
+#define PF_REZ_TYPE (long)
+#define STRTOL(s, e, b) strtol(s, e, b)
+#endif
+
+/* TODO: use bb_strtol[l]? It's easier to check for errors... */
+
+/* A value is.... */
+struct valinfo {
+	TYPE type;			/* Which kind. */
+	union {				/* The value itself. */
+		arith_t i;
+		char *s;
+	} u;
+};
+typedef struct valinfo VALUE;
+
+/* The arguments given to the program, minus the program name.  */
+static char **args;
+
+static VALUE *docolon(VALUE * sv, VALUE * pv);
+static VALUE *eval(void);
+static VALUE *int_value(arith_t i);
+static VALUE *str_value(char *s);
+static int nextarg(char *str);
+static int null(VALUE * v);
+static int toarith(VALUE * v);
+static void freev(VALUE * v);
+static void tostring(VALUE * v);
+
+int expr_main(int argc, char **argv)
+{
+	VALUE *v;
+
+	if (argc == 1) {
+		bb_error_msg_and_die("too few arguments");
+	}
+
+	args = argv + 1;
+
+	v = eval();
+	if (*args)
+		bb_error_msg_and_die("syntax error");
+
+	if (v->type == integer)
+		printf("%" PF_REZ "d\n", PF_REZ_TYPE v->u.i);
+	else
+		puts(v->u.s);
+
+	fflush_stdout_and_exit(null(v));
+}
+
+/* Return a VALUE for I.  */
+
+static VALUE *int_value(arith_t i)
+{
+	VALUE *v;
+
+	v = xmalloc(sizeof(VALUE));
+	v->type = integer;
+	v->u.i = i;
+	return v;
+}
+
+/* Return a VALUE for S.  */
+
+static VALUE *str_value(char *s)
+{
+	VALUE *v;
+
+	v = xmalloc(sizeof(VALUE));
+	v->type = string;
+	v->u.s = xstrdup(s);
+	return v;
+}
+
+/* Free VALUE V, including structure components.  */
+
+static void freev(VALUE * v)
+{
+	if (v->type == string)
+		free(v->u.s);
+	free(v);
+}
+
+/* Return nonzero if V is a null-string or zero-number.  */
+
+static int null(VALUE * v)
+{
+	if (v->type == integer)
+		return v->u.i == 0;
+	else				/* string: */
+		return v->u.s[0] == '\0' || strcmp(v->u.s, "0") == 0;
+}
+
+/* Coerce V to a string value (can't fail).  */
+
+static void tostring(VALUE * v)
+{
+	if (v->type == integer) {
+		v->u.s = xasprintf("%" PF_REZ "d", PF_REZ_TYPE v->u.i);
+		v->type = string;
+	}
+}
+
+/* Coerce V to an integer value.  Return 1 on success, 0 on failure.  */
+
+static int toarith(VALUE * v)
+{
+	if (v->type == string) {
+		arith_t i;
+		char *e;
+
+		/* Don't interpret the empty string as an integer.  */
+		/* Currently does not worry about overflow or int/long differences. */
+		i = STRTOL(v->u.s, &e, 10);
+		if ((v->u.s == e) || *e)
+			return 0;
+		free(v->u.s);
+		v->u.i = i;
+		v->type = integer;
+	}
+	return 1;
+}
+
+/* Return nonzero if the next token matches STR exactly.
+   STR must not be NULL.  */
+
+static int nextarg(char *str)
+{
+	if (*args == NULL)
+		return 0;
+	return strcmp(*args, str) == 0;
+}
+
+/* The comparison operator handling functions.  */
+
+static int cmp_common(VALUE * l, VALUE * r, int op)
+{
+	int cmpval;
+
+	if (l->type == string || r->type == string) {
+		tostring(l);
+		tostring(r);
+		cmpval = strcmp(l->u.s, r->u.s);
+	} else
+		cmpval = l->u.i - r->u.i;
+	if (op == '<')
+		return cmpval < 0;
+	else if (op == ('L' + 'E'))
+		return cmpval <= 0;
+	else if (op == '=')
+		return cmpval == 0;
+	else if (op == '!')
+		return cmpval != 0;
+	else if (op == '>')
+		return cmpval > 0;
+	else				/* >= */
+		return cmpval >= 0;
+}
+
+/* The arithmetic operator handling functions.  */
+
+static arith_t arithmetic_common(VALUE * l, VALUE * r, int op)
+{
+	arith_t li, ri;
+
+	if (!toarith(l) || !toarith(r))
+		bb_error_msg_and_die("non-numeric argument");
+	li = l->u.i;
+	ri = r->u.i;
+	if ((op == '/' || op == '%') && ri == 0)
+		bb_error_msg_and_die("division by zero");
+	if (op == '+')
+		return li + ri;
+	else if (op == '-')
+		return li - ri;
+	else if (op == '*')
+		return li * ri;
+	else if (op == '/')
+		return li / ri;
+	else
+		return li % ri;
+}
+
+/* Do the : operator.
+   SV is the VALUE for the lhs (the string),
+   PV is the VALUE for the rhs (the pattern).  */
+
+static VALUE *docolon(VALUE * sv, VALUE * pv)
+{
+	VALUE *v;
+	regex_t re_buffer;
+	const int NMATCH = 2;
+	regmatch_t re_regs[NMATCH];
+
+	tostring(sv);
+	tostring(pv);
+
+	if (pv->u.s[0] == '^') {
+		fprintf(stderr, "\
+warning: unportable BRE: `%s': using `^' as the first character\n\
+of a basic regular expression is not portable; it is being ignored", pv->u.s);
+	}
+
+	memset(&re_buffer, 0, sizeof(re_buffer));
+	memset(re_regs, 0, sizeof(*re_regs));
+	if (regcomp(&re_buffer, pv->u.s, 0) != 0)
+		bb_error_msg_and_die("invalid regular expression");
+
+	/* expr uses an anchored pattern match, so check that there was a
+	 * match and that the match starts at offset 0. */
+	if (regexec(&re_buffer, sv->u.s, NMATCH, re_regs, 0) != REG_NOMATCH &&
+		re_regs[0].rm_so == 0) {
+		/* Were \(...\) used? */
+		if (re_buffer.re_nsub > 0) {
+			sv->u.s[re_regs[1].rm_eo] = '\0';
+			v = str_value(sv->u.s + re_regs[1].rm_so);
+		} else
+			v = int_value(re_regs[0].rm_eo);
+	} else {
+		/* Match failed -- return the right kind of null.  */
+		if (re_buffer.re_nsub > 0)
+			v = str_value("");
+		else
+			v = int_value(0);
+	}
+	return v;
+}
+
+/* Handle bare operands and ( expr ) syntax.  */
+
+static VALUE *eval7(void)
+{
+	VALUE *v;
+
+	if (!*args)
+		bb_error_msg_and_die("syntax error");
+
+	if (nextarg("(")) {
+		args++;
+		v = eval();
+		if (!nextarg(")"))
+			bb_error_msg_and_die("syntax error");
+		args++;
+		return v;
+	}
+
+	if (nextarg(")"))
+		bb_error_msg_and_die("syntax error");
+
+	return str_value(*args++);
+}
+
+/* Handle match, substr, index, length, and quote keywords.  */
+
+static VALUE *eval6(void)
+{
+	VALUE *l, *r, *v, *i1, *i2;
+
+	if (nextarg("quote")) {
+		args++;
+		if (!*args)
+			bb_error_msg_and_die("syntax error");
+		return str_value(*args++);
+	} else if (nextarg("length")) {
+		args++;
+		r = eval6();
+		tostring(r);
+		v = int_value(strlen(r->u.s));
+		freev(r);
+		return v;
+	} else if (nextarg("match")) {
+		args++;
+		l = eval6();
+		r = eval6();
+		v = docolon(l, r);
+		freev(l);
+		freev(r);
+		return v;
+	} else if (nextarg("index")) {
+		args++;
+		l = eval6();
+		r = eval6();
+		tostring(l);
+		tostring(r);
+		v = int_value(strcspn(l->u.s, r->u.s) + 1);
+		if (v->u.i == (arith_t) strlen(l->u.s) + 1)
+			v->u.i = 0;
+		freev(l);
+		freev(r);
+		return v;
+	} else if (nextarg("substr")) {
+		args++;
+		l = eval6();
+		i1 = eval6();
+		i2 = eval6();
+		tostring(l);
+		if (!toarith(i1) || !toarith(i2)
+			|| i1->u.i > (arith_t) strlen(l->u.s)
+			|| i1->u.i <= 0 || i2->u.i <= 0)
+			v = str_value("");
+		else {
+			v = xmalloc(sizeof(VALUE));
+			v->type = string;
+			v->u.s = xstrndup(l->u.s + i1->u.i - 1, i2->u.i);
+		}
+		freev(l);
+		freev(i1);
+		freev(i2);
+		return v;
+	} else
+		return eval7();
+}
+
+/* Handle : operator (pattern matching).
+   Calls docolon to do the real work.  */
+
+static VALUE *eval5(void)
+{
+	VALUE *l, *r, *v;
+
+	l = eval6();
+	while (nextarg(":")) {
+		args++;
+		r = eval6();
+		v = docolon(l, r);
+		freev(l);
+		freev(r);
+		l = v;
+	}
+	return l;
+}
+
+/* Handle *, /, % operators.  */
+
+static VALUE *eval4(void)
+{
+	VALUE *l, *r;
+	int op;
+	arith_t val;
+
+	l = eval5();
+	while (1) {
+		if (nextarg("*"))
+			op = '*';
+		else if (nextarg("/"))
+			op = '/';
+		else if (nextarg("%"))
+			op = '%';
+		else
+			return l;
+		args++;
+		r = eval5();
+		val = arithmetic_common(l, r, op);
+		freev(l);
+		freev(r);
+		l = int_value(val);
+	}
+}
+
+/* Handle +, - operators.  */
+
+static VALUE *eval3(void)
+{
+	VALUE *l, *r;
+	int op;
+	arith_t val;
+
+	l = eval4();
+	while (1) {
+		if (nextarg("+"))
+			op = '+';
+		else if (nextarg("-"))
+			op = '-';
+		else
+			return l;
+		args++;
+		r = eval4();
+		val = arithmetic_common(l, r, op);
+		freev(l);
+		freev(r);
+		l = int_value(val);
+	}
+}
+
+/* Handle comparisons.  */
+
+static VALUE *eval2(void)
+{
+	VALUE *l, *r;
+	int op;
+	arith_t val;
+
+	l = eval3();
+	while (1) {
+		if (nextarg("<"))
+			op = '<';
+		else if (nextarg("<="))
+			op = 'L' + 'E';
+		else if (nextarg("=") || nextarg("=="))
+			op = '=';
+		else if (nextarg("!="))
+			op = '!';
+		else if (nextarg(">="))
+			op = 'G' + 'E';
+		else if (nextarg(">"))
+			op = '>';
+		else
+			return l;
+		args++;
+		r = eval3();
+		toarith(l);
+		toarith(r);
+		val = cmp_common(l, r, op);
+		freev(l);
+		freev(r);
+		l = int_value(val);
+	}
+}
+
+/* Handle &.  */
+
+static VALUE *eval1(void)
+{
+	VALUE *l, *r;
+
+	l = eval2();
+	while (nextarg("&")) {
+		args++;
+		r = eval2();
+		if (null(l) || null(r)) {
+			freev(l);
+			freev(r);
+			l = int_value(0);
+		} else
+			freev(r);
+	}
+	return l;
+}
+
+/* Handle |.  */
+
+static VALUE *eval(void)
+{
+	VALUE *l, *r;
+
+	l = eval1();
+	while (nextarg("|")) {
+		args++;
+		r = eval1();
+		if (null(l)) {
+			freev(l);
+			l = r;
+		} else
+			freev(r);
+	}
+	return l;
+}