attack the biggest stack users:

-mkfs_minix_main [busybox_unstripped]:                  4288
-mkfs_minix_main [busybox_unstripped]:                  4276
-grave [busybox_unstripped]:                            4260
(bzip2 users too - not listed)

price we pay in code size increase:
mainSort                                            2458    2515     +57
grave                                               1005    1058     +53
sendMTFValues                                       2177    2195     +18
BZ2_blockSort                                        122     125      +3
mkfs_minix_main                                     3070    3022     -48
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 4/1 up/down: 131/-48)            Total: 83 bytes

1 files changed, 14 insertions, 1 deletions

diff --git a/shell/msh.c b/shell/msh.c
index 32953f4ed..9f95fe28a 100644
--- a/shell/msh.c
+++ b/shell/msh.c
@@ -735,6 +735,9 @@ struct globals {
         char filechar_cmdbuf[BUFSIZ];
         char line[LINELIM];
         char child_cmd[LINELIM];
+
+        char grave__var_name[LINELIM];
+        char grave__alt_value[LINELIM];
 };
 
 #define G (*ptr_to_globals)
@@ -746,6 +749,9 @@ struct globals {
 #define filechar_cmdbuf (G.filechar_cmdbuf)
 #define line            (G.line           )
 #define child_cmd       (G.child_cmd      )
+#define INIT_G() do { \
+        PTR_TO_GLOBALS = xzalloc(sizeof(G)); \
+} while (0)
 
 
 #ifdef MSHDEBUG
@@ -4042,8 +4048,12 @@ static int grave(int quoted)
                         ignore_once = 1;
                 if (*src == '$' && !ignore && !ignore_once) {
                         struct var *vp;
+                        /* moved to G to reduce stack usage
                         char var_name[LINELIM];
                         char alt_value[LINELIM];
+                        */
+#define var_name (G.grave__var_name)
+#define alt_value (G.grave__alt_value)
                         int var_index = 0;
                         int alt_index = 0;
                         char operator = 0;
@@ -4131,6 +4141,8 @@ static int grave(int quoted)
                                         count++;
                                 }
                         }
+#undef var_name
+#undef alt_value
                 } else {
                         *dest++ = *src++;
                         count++;
@@ -5173,7 +5185,8 @@ int msh_main(int argc, char **argv)
         char *name, **ap;
         int (*iof) (struct ioarg *);
 
-        PTR_TO_GLOBALS = xzalloc(sizeof(G));
+        INIT_G();
+
         sharedbuf.id = AFID_NOBUF;
         mainbuf.id = AFID_NOBUF;
         e.linep = line;