* - reduced 464 bytes.
* - 64 math support
*
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
- *
+ * Licensed under GPLv2 or later, see file LICENSE in this source tree.
*/
/* This program evaluates expressions. Each token (operator, operand,
/* no getopt needed */
-#include <stdio.h>
-#include <string.h>
-#include <stdlib.h>
-#include <regex.h>
-#include <sys/types.h>
-#include <errno.h>
-#include "busybox.h"
-
-
-/* The kinds of value we can have. */
-enum valtype {
- integer,
- string
-};
-typedef enum valtype TYPE;
+//usage:#define expr_trivial_usage
+//usage: "EXPRESSION"
+//usage:#define expr_full_usage "\n\n"
+//usage: "Print the value of EXPRESSION to stdout\n"
+//usage: "\n"
+//usage: "EXPRESSION may be:\n"
+//usage: " ARG1 | ARG2 ARG1 if it is neither null nor 0, otherwise ARG2\n"
+//usage: " ARG1 & ARG2 ARG1 if neither argument is null or 0, otherwise 0\n"
+//usage: " ARG1 < ARG2 1 if ARG1 is less than ARG2, else 0. Similarly:\n"
+//usage: " ARG1 <= ARG2\n"
+//usage: " ARG1 = ARG2\n"
+//usage: " ARG1 != ARG2\n"
+//usage: " ARG1 >= ARG2\n"
+//usage: " ARG1 > ARG2\n"
+//usage: " ARG1 + ARG2 Sum of ARG1 and ARG2. Similarly:\n"
+//usage: " ARG1 - ARG2\n"
+//usage: " ARG1 * ARG2\n"
+//usage: " ARG1 / ARG2\n"
+//usage: " ARG1 % ARG2\n"
+//usage: " STRING : REGEXP Anchored pattern match of REGEXP in STRING\n"
+//usage: " match STRING REGEXP Same as STRING : REGEXP\n"
+//usage: " substr STRING POS LENGTH Substring of STRING, POS counted from 1\n"
+//usage: " index STRING CHARS Index in STRING where any CHARS is found, or 0\n"
+//usage: " length STRING Length of STRING\n"
+//usage: " quote TOKEN Interpret TOKEN as a string, even if\n"
+//usage: " it is a keyword like 'match' or an\n"
+//usage: " operator like '/'\n"
+//usage: " (EXPRESSION) Value of EXPRESSION\n"
+//usage: "\n"
+//usage: "Beware that many operators need to be escaped or quoted for shells.\n"
+//usage: "Comparisons are arithmetic if both ARGs are numbers, else\n"
+//usage: "lexicographical. Pattern matches return the string matched between\n"
+//usage: "\\( and \\) or null; if \\( and \\) are not used, they return the number\n"
+//usage: "of characters matched or 0."
+
+#include "libbb.h"
+#include "xregex.h"
#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... */
+
+/* The kinds of value we can have. */
+enum {
+ INTEGER,
+ STRING
+};
+
/* A value is.... */
struct valinfo {
- TYPE type; /* Which kind. */
+ smallint type; /* Which kind. */
union { /* The value itself. */
arith_t i;
char *s;
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;
+struct globals {
+ char **args;
+} FIX_ALIASING;
+#define G (*(struct globals*)&bb_common_bufsiz1)
+#define INIT_G() do { } while (0)
- 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");
+/* forward declarations */
+static VALUE *eval(void);
- if (v->type == integer)
- printf ("%" PF_REZ "d\n", v->u.i);
- else
- puts (v->u.s);
-
- exit (null (v));
-}
/* Return a VALUE for I. */
-static VALUE *int_value (arith_t i)
+static VALUE *int_value(arith_t i)
{
VALUE *v;
- v = xmalloc (sizeof(VALUE));
- v->type = integer;
+ v = xzalloc(sizeof(VALUE));
+ if (INTEGER) /* otherwise xzaaloc did it already */
+ v->type = INTEGER;
v->u.i = i;
return v;
}
/* Return a VALUE for S. */
-static VALUE *str_value (char *s)
+static VALUE *str_value(const char *s)
{
VALUE *v;
- v = xmalloc (sizeof(VALUE));
- v->type = string;
- v->u.s = bb_xstrdup (s);
+ v = xzalloc(sizeof(VALUE));
+ if (STRING) /* otherwise xzaaloc did it already */
+ v->type = STRING;
+ v->u.s = xstrdup(s);
return v;
}
/* Free VALUE V, including structure components. */
-static void freev (VALUE *v)
+static void freev(VALUE *v)
{
- if (v->type == string)
- free (v->u.s);
- free (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)
+static int null(VALUE *v)
{
- switch (v->type) {
- case integer:
- return v->u.i == 0;
- default: /* string: */
- return v->u.s[0] == '\0' || strcmp (v->u.s, "0") == 0;
- }
+ if (v->type == INTEGER)
+ return v->u.i == 0;
+ /* STRING: */
+ return v->u.s[0] == '\0' || LONE_CHAR(v->u.s, '0');
}
-/* Coerce V to a string value (can't fail). */
+/* Coerce V to a STRING value (can't fail). */
-static void tostring (VALUE *v)
+static void tostring(VALUE *v)
{
- if (v->type == integer) {
- v->u.s = bb_xasprintf ("%" PF_REZ "d", v->u.i);
- v->type = string;
+ 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. */
+/* Coerce V to an INTEGER value. Return 1 on success, 0 on failure. */
-static int toarith (VALUE *v)
+static bool toarith(VALUE *v)
{
- if(v->type == string) {
+ if (v->type == STRING) {
arith_t i;
char *e;
i = STRTOL(v->u.s, &e, 10);
if ((v->u.s == e) || *e)
return 0;
- free (v->u.s);
+ free(v->u.s);
v->u.i = i;
- v->type = integer;
+ v->type = INTEGER;
}
return 1;
}
-/* Return nonzero if the next token matches STR exactly.
+/* Return str[0]+str[1] if the next token matches STR exactly.
STR must not be NULL. */
-static int
-nextarg (char *str)
+static int nextarg(const char *str)
{
- if (*args == NULL)
+ if (*G.args == NULL || strcmp(*G.args, str) != 0)
return 0;
- return strcmp (*args, str) == 0;
+ return (unsigned char)str[0] + (unsigned char)str[1];
}
/* The comparison operator handling functions. */
-static int cmp_common (VALUE *l, VALUE *r, int op)
+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;
- switch(op) {
- case '<':
- return cmpval < 0;
- case ('L'+'E'):
- return cmpval <= 0;
- case '=':
- return cmpval == 0;
- case '!':
- return cmpval != 0;
- case '>':
- return cmpval > 0;
- default: /* >= */
- return cmpval >= 0;
+ arith_t ll, rr;
+
+ ll = l->u.i;
+ rr = r->u.i;
+ if (l->type == STRING || r->type == STRING) {
+ tostring(l);
+ tostring(r);
+ ll = strcmp(l->u.s, r->u.s);
+ rr = 0;
}
+ /* calculating ll - rr and checking the result is prone to overflows.
+ * We'll do it differently: */
+ if (op == '<')
+ return ll < rr;
+ if (op == ('<' + '='))
+ return ll <= rr;
+ if (op == '=' || (op == '=' + '='))
+ return ll == rr;
+ if (op == '!' + '=')
+ return ll != rr;
+ if (op == '>')
+ return ll > rr;
+ /* >= */
+ return ll >= rr;
}
/* The arithmetic operator handling functions. */
-static arith_t arithmetic_common (VALUE *l, VALUE *r, int op)
+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");
- switch(op) {
- case '+':
+ 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 == '+')
return li + ri;
- case '-':
+ if (op == '-')
return li - ri;
- case '*':
+ if (op == '*')
return li * ri;
- case '/':
+ if (ri == 0)
+ bb_error_msg_and_die("division by zero");
+ if (op == '/')
return li / ri;
- default:
- return li % ri;
- }
+ 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)
+static VALUE *docolon(VALUE *sv, VALUE *pv)
{
+ enum { NMATCH = 2 };
VALUE *v;
regex_t re_buffer;
- const int NMATCH = 2;
regmatch_t re_regs[NMATCH];
- tostring (sv);
- tostring (pv);
+ 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);
+ bb_error_msg(
+"warning: '%s': using '^' as the first character\n"
+"of a basic regular expression is not portable; it is 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");
+ memset(&re_buffer, 0, sizeof(re_buffer));
+ memset(re_regs, 0, sizeof(re_regs));
+ xregcomp(&re_buffer, pv->u.s, 0);
/* 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) {
+ 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) {
+ if (re_buffer.re_nsub > 0 && re_regs[1].rm_so >= 0) {
sv->u.s[re_regs[1].rm_eo] = '\0';
- v = str_value (sv->u.s + re_regs[1].rm_so);
+ v = str_value(sv->u.s + re_regs[1].rm_so);
+ } else {
+ v = int_value(re_regs[0].rm_eo);
}
- else
- v = int_value (re_regs[0].rm_eo);
- }
- else {
+ } else {
/* Match failed -- return the right kind of null. */
if (re_buffer.re_nsub > 0)
- v = str_value ("");
+ v = str_value("");
else
- v = int_value (0);
+ v = int_value(0);
}
+ regfree(&re_buffer);
return v;
}
/* Handle bare operands and ( expr ) syntax. */
-static VALUE *eval7 (void)
+static VALUE *eval7(void)
{
VALUE *v;
- if (!*args)
- bb_error_msg_and_die ( "syntax error");
+ if (!*G.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("(")) {
+ G.args++;
+ v = eval();
+ if (!nextarg(")"))
+ bb_error_msg_and_die("syntax error");
+ G.args++;
+ return v;
+ }
- if (nextarg (")"))
- bb_error_msg_and_die ( "syntax error");
+ if (nextarg(")"))
+ bb_error_msg_and_die("syntax error");
- return str_value (*args++);
+ return str_value(*G.args++);
}
/* Handle match, substr, index, length, and quote keywords. */
-static VALUE *eval6 (void)
+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++);
+ static const char keywords[] ALIGN1 =
+ "quote\0""length\0""match\0""index\0""substr\0";
+
+ VALUE *r, *i1, *i2;
+ VALUE *l = l; /* silence gcc */
+ VALUE *v = v; /* silence gcc */
+ int key = *G.args ? index_in_strings(keywords, *G.args) + 1 : 0;
+
+ if (key == 0) /* not a keyword */
+ return eval7();
+ G.args++; /* We have a valid token, so get the next argument. */
+ if (key == 1) { /* quote */
+ if (!*G.args)
+ bb_error_msg_and_die("syntax error");
+ return str_value(*G.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;
+ if (key == 2) { /* length */
+ r = eval6();
+ tostring(r);
+ v = int_value(strlen(r->u.s));
+ freev(r);
+ } else
+ l = eval6();
+
+ if (key == 3) { /* match */
+ r = eval6();
+ v = docolon(l, r);
+ freev(l);
+ freev(r);
}
- 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)
+ if (key == 4) { /* index */
+ 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;
+ freev(l);
+ freev(r);
}
- 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 ("");
+ if (key == 5) { /* substr */
+ 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 = bb_xstrndup(l->u.s + i1->u.i - 1, i2->u.i);
+ 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;
+ freev(l);
+ freev(i1);
+ freev(i2);
}
- else
- return eval7 ();
+ return v;
}
/* Handle : operator (pattern matching).
Calls docolon to do the real work. */
-static VALUE *eval5 (void)
+static VALUE *eval5(void)
{
VALUE *l, *r, *v;
- l = eval6 ();
- while (nextarg (":")) {
- args++;
- r = eval6 ();
- v = docolon (l, r);
- freev (l);
- freev (r);
+ l = eval6();
+ while (nextarg(":")) {
+ G.args++;
+ r = eval6();
+ v = docolon(l, r);
+ freev(l);
+ freev(r);
l = v;
}
return l;
/* Handle *, /, % operators. */
-static VALUE *eval4 (void)
+static VALUE *eval4(void)
{
VALUE *l, *r;
int op;
arith_t val;
- l = eval5 ();
+ 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);
+ op = nextarg("*");
+ if (!op) { op = nextarg("/");
+ if (!op) { op = nextarg("%");
+ if (!op) return l;
+ }}
+ G.args++;
+ r = eval5();
+ val = arithmetic_common(l, r, op);
+ freev(l);
+ freev(r);
+ l = int_value(val);
}
}
/* Handle +, - operators. */
-static VALUE *eval3 (void)
+static VALUE *eval3(void)
{
VALUE *l, *r;
int op;
arith_t val;
- l = eval4 ();
+ 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);
+ op = nextarg("+");
+ if (!op) {
+ op = nextarg("-");
+ if (!op) return l;
+ }
+ G.args++;
+ r = eval4();
+ val = arithmetic_common(l, r, op);
+ freev(l);
+ freev(r);
+ l = int_value(val);
}
}
/* Handle comparisons. */
-static VALUE *eval2 (void)
+static VALUE *eval2(void)
{
VALUE *l, *r;
int op;
arith_t val;
- l = eval3 ();
+ 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);
+ op = nextarg("<");
+ if (!op) { op = nextarg("<=");
+ if (!op) { op = nextarg("=");
+ if (!op) { op = nextarg("==");
+ if (!op) { op = nextarg("!=");
+ if (!op) { op = nextarg(">=");
+ if (!op) { op = nextarg(">");
+ if (!op) return l;
+ }}}}}}
+ G.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)
+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);
+ l = eval2();
+ while (nextarg("&")) {
+ G.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)
+static VALUE *eval(void)
{
VALUE *l, *r;
- l = eval1 ();
- while (nextarg ("|")) {
- args++;
- r = eval1 ();
- if (null (l)) {
- freev (l);
+ l = eval1();
+ while (nextarg("|")) {
+ G.args++;
+ r = eval1();
+ if (null(l)) {
+ freev(l);
l = r;
- }
- else
- freev (r);
+ } else
+ freev(r);
}
return l;
}
+
+int expr_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+int expr_main(int argc UNUSED_PARAM, char **argv)
+{
+ VALUE *v;
+
+ INIT_G();
+
+ xfunc_error_retval = 2; /* coreutils compat */
+ G.args = argv + 1;
+ if (*G.args == NULL) {
+ bb_error_msg_and_die("too few arguments");
+ }
+ v = eval();
+ if (*G.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));
+}