3 files changed, 31 insertions, 14 deletions

diff --git a/include/libbb.h b/include/libbb.h
index b65043cf3..17a5940ca 100644
--- a/include/libbb.h
+++ b/include/libbb.h
@@ -289,8 +289,6 @@ char *concat_path_file(const char *path, const char *filename);
 char *concat_subpath_file(const char *path, const char *filename);
 char *last_char_is(const char *s, int c);
 
-extern long arith (const char *startbuf, int *errcode);
-
 int read_package_field(const char *package_buffer, char **field_name, char **field_value);
 //#warning yuk!
 char *fgets_str(FILE *file, const char *terminating_string);
diff --git a/shell/Config.in b/shell/Config.in
index b064ed41b..c8f4a936c 100644
--- a/shell/Config.in
+++ b/shell/Config.in
@@ -67,6 +67,15 @@ config CONFIG_ASH_MATH_SUPPORT
         help
           Enable math support in the ash shell.
 
+config CONFIG_ASH_MATH_SUPPORT_64
+        bool "    Extend Posix math support to 64 bit"
+        default n
+        depends on CONFIG_ASH_MATH_SUPPORT
+        help
+          Enable 64-bit math support in the ash shell.  This will make
+          the shell slightly larger, but will allow computation with very
+          large numbers.
+
 config CONFIG_ASH_GETOPTS
         bool "  Enable getopt builtin to parse positional parameters"
         default n
diff --git a/shell/ash.c b/shell/ash.c
index e2205efd2..a1c4f346b 100644
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -1446,7 +1446,13 @@ static void defun(char *, union node *);
 static void unsetfunc(const char *);
 
 #ifdef CONFIG_ASH_MATH_SUPPORT
-static long dash_arith(const char *);
+#ifdef CONFIG_ASH_MATH_SUPPORT_64
+typedef int64_t arith_t;
+#else
+typedef long arith_t;
+#endif
+static arith_t dash_arith(const char *);
+static arith_t arith(const char *expr, int *perrcode);
 #endif
 
 #ifdef CONFIG_ASH_RANDOM_SUPPORT
@@ -4531,7 +4537,7 @@ static void ifsfree(void);
 static void expandmeta(struct strlist *, int);
 static int patmatch(char *, const char *);
 
-static int cvtnum(long);
+static int cvtnum(arith_t);
 static size_t esclen(const char *, const char *);
 static char *scanleft(char *, char *, char *, char *, int, int);
 static char *scanright(char *, char *, char *, char *, int, int);
@@ -5902,12 +5908,16 @@ casematch(union node *pattern, char *val)
  */
 
 static int
-cvtnum(long num)
+cvtnum(arith_t num)
 {
         int len;
 
         expdest = makestrspace(32, expdest);
+#ifdef CONFIG_ASH_MATH_SUPPORT_64
+        len = fmtstr(expdest, 32, "%lld", (long long) num);
+#else
         len = fmtstr(expdest, 32, "%ld", num);
+#endif
         STADJUST(len, expdest);
         return len;
 }
@@ -12488,10 +12498,10 @@ static int timescmd(int ac, char **av)
 }
 
 #ifdef CONFIG_ASH_MATH_SUPPORT
-static long
+static arith_t
 dash_arith(const char *s)
 {
-        long result;
+        arith_t result;
         int errcode = 0;
 
         INTOFF;
@@ -12523,7 +12533,7 @@ static int
 letcmd(int argc, char **argv)
 {
         char **ap;
-        long i;
+        arith_t i;
 
         ap = argv + 1;
         if(!*ap)
@@ -13094,8 +13104,8 @@ static inline int is_right_associativity(operator prec)
 
 
 typedef struct ARITCH_VAR_NUM {
-        long val;
-        long contidional_second_val;
+        arith_t val;
+        arith_t contidional_second_val;
         char contidional_second_val_initialized;
         char *var;      /* if NULL then is regular number,
                            else is variable name */
@@ -13152,9 +13162,9 @@ static int arith_lookup_val(v_n_t *t)
 static inline int
 arith_apply(operator op, v_n_t *numstack, v_n_t **numstackptr)
 {
-        long numptr_val;
+        int64_t numptr_val;
         v_n_t *numptr_m1;
-        long rez;
+        int64_t rez;
         int ret_arith_lookup_val;
 
         if (NUMPTR == numstack) goto err; /* There is no operator that can work
@@ -13280,7 +13290,7 @@ arith_apply(operator op, v_n_t *numstack, v_n_t **numstackptr)
                         goto err;
                 }
                 /* save to shell variable */
-                sprintf(buf, "%ld", rez);
+                sprintf(buf, "%lld", (long long) rez);
                 setvar(numptr_m1->var, buf, 0);
                 /* after saving, make previous value for v++ or v-- */
                 if(op == TOK_POST_INC)
@@ -13343,7 +13353,7 @@ static const char op_tokens[] = {
 #define endexpression &op_tokens[sizeof(op_tokens)-7]
 
 
-extern long arith (const char *expr, int *perrcode)
+static arith_t arith (const char *expr, int *perrcode)
 {
     register char arithval; /* Current character under analysis */
     operator lasttok, op;