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authorDenis Vlasenko2009-04-06 12:24:58 +0000
committerDenis Vlasenko2009-04-06 12:24:58 +0000
commitb1d11bf45ec55d469f47c1341d593fdae790bb6a (patch)
tree1451bb52ef01ba105e7a33315010042f77f793ea
parentd0b4a8c285c6fd79b397dd22131ef3a66d8f3d7f (diff)
downloadbusybox-b1d11bf45ec55d469f47c1341d593fdae790bb6a.zip
busybox-b1d11bf45ec55d469f47c1341d593fdae790bb6a.tar.gz
hush: more efficient filtering of "safe" arithmetic
function old new delta expand_variables 2170 2147 -23
-rw-r--r--shell/hush.c28
1 files changed, 9 insertions, 19 deletions
diff --git a/shell/hush.c b/shell/hush.c
index 3aae7d7..e86f0d2 100644
--- a/shell/hush.c
+++ b/shell/hush.c
@@ -1782,24 +1782,15 @@ static int expand_vars_to_list(o_string *output, int n, char *arg, char or_mask)
debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
/* Optional: skip expansion if expr is simple ("a + 3", "i++" etc) */
- exp_str = arg;
- while (1) {
- unsigned char c = *exp_str++;
- if (c == '\0') {
- exp_str = NULL;
- goto skip_expand;
- }
- if (isdigit(c))
- continue;
- if (strchr(" \t+-*/%<>()_", c) != NULL)
- continue;
- c |= 0x20; /* tolower */
- if (c >= 'a' && c <= 'z')
- continue;
- break;
- }
- /* We need to expand. Example: "echo $(($a + 1)) $((1 + $((2)) ))" */
- {
+ exp_str = NULL;
+ if (strchr(arg, '$') != NULL
+#if ENABLE_HUSH_TICK
+ || strchr(arg, '`') != NULL
+#endif
+ ) {
+ /* We need to expand. Example:
+ * echo $(($a + `echo 1`)) $((1 + $((2)) ))
+ */
struct in_str input;
o_string dest = NULL_O_STRING;
@@ -1810,7 +1801,6 @@ static int expand_vars_to_list(o_string *output, int n, char *arg, char or_mask)
//bb_error_msg("'%s' -> '%s'", dest.data, exp_str);
o_free(&dest);
}
- skip_expand:
hooks.lookupvar = get_local_var_value;
hooks.setvar = arith_set_local_var;
hooks.endofname = endofname;