From b1d11bf45ec55d469f47c1341d593fdae790bb6a Mon Sep 17 00:00:00 2001 From: Denis Vlasenko Date: Mon, 6 Apr 2009 12:24:58 +0000 Subject: [PATCH] hush: more efficient filtering of "safe" arithmetic function old new delta expand_variables 2170 2147 -23 --- shell/hush.c | 28 +++++++++------------------- 1 file changed, 9 insertions(+), 19 deletions(-) diff --git a/shell/hush.c b/shell/hush.c index 3aae7d7c1..e86f0d22f 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; -- 2.25.1