hush: speed up set_local_var
function old new delta
set_local_var 265 290 +25
diff --git a/shell/hush.c b/shell/hush.c
index 58a57d9..53b1f3f 100644
--- a/shell/hush.c
+++ b/shell/hush.c
@@ -1266,16 +1266,16 @@
static int set_local_var(char *str, int flg_export, int flg_read_only)
{
struct variable *cur;
- char *value;
+ char *eq_sign;
int name_len;
- value = strchr(str, '=');
- if (!value) { /* not expected to ever happen? */
+ eq_sign = strchr(str, '=');
+ if (!eq_sign) { /* not expected to ever happen? */
free(str);
return -1;
}
- name_len = value - str + 1; /* including '=' */
+ name_len = eq_sign - str + 1; /* including '=' */
cur = G.top_var; /* cannot be NULL (we have HUSH_VERSION and it's RO) */
while (1) {
if (strncmp(cur->varstr, str, name_len) != 0) {
@@ -1288,7 +1288,6 @@
continue;
}
/* We found an existing var with this name */
- *value = '\0';
if (cur->flg_read_only) {
#if !BB_MMU
if (!flg_read_only)
@@ -1297,11 +1296,13 @@
free(str);
return -1;
}
-//TODO: optimize out redundant unsetenv/putenv's?
- debug_printf_env("%s: unsetenv '%s'\n", __func__, str);
- unsetenv(str); /* just in case */
- *value = '=';
- if (strcmp(cur->varstr, str) == 0) {
+ if (flg_export == -1) {
+ debug_printf_env("%s: unsetenv '%s'\n", __func__, str);
+ *eq_sign = '\0';
+ unsetenv(str);
+ *eq_sign = '=';
+ }
+ if (strcmp(cur->varstr + name_len, eq_sign + 1) == 0) {
free_and_exp:
free(str);
goto exp;