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authorDenys Vlasenko <vda.linux@googlemail.com>2010-05-20 14:27:42 (GMT)
committer Denys Vlasenko <vda.linux@googlemail.com>2010-05-20 14:27:42 (GMT)
commite3be7842be3ccac389efd2ac51b18773c58852c5 (patch)
tree9b0cda850de07e6cb10dafb442d60e98b7fb4aa6
parentcddbb610cb0ea8d74668653aeaded710d2d13768 (diff)
downloadbusybox-e3be7842be3ccac389efd2ac51b18773c58852c5.tar.gz
busybox-e3be7842be3ccac389efd2ac51b18773c58852c5.tar.bz2
hush: shrink variable expansion code
function old new delta expand_vars_to_list 2164 2012 -152 Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
-rw-r--r--shell/hush.c39
1 files changed, 19 insertions, 20 deletions
diff --git a/shell/hush.c b/shell/hush.c
index 8da9439..824a5b5 100644
--- a/shell/hush.c
+++ b/shell/hush.c
@@ -2568,35 +2568,33 @@ static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg, char
#endif
default: /* <SPECIAL_VAR_SYMBOL>varname<SPECIAL_VAR_SYMBOL> */
case_default: {
- bool exp_len = false;
- bool exp_null = false;
char *var = arg;
+ bool exp_len;
+ char exp_op;
char exp_save = exp_save; /* for compiler */
- char exp_op = exp_op; /* for compiler */
+ char *exp_saveptr = exp_saveptr; /* points to expansion operator */
char *exp_word = exp_word; /* for compiler */
- size_t exp_off = 0;
*p = '\0';
arg[0] = first_ch & 0x7f;
/* prepare for expansions */
+ exp_len = false;
+ exp_op = 0;
if (var[0] == '#') {
/* handle length expansion ${#var} */
exp_len = true;
++var;
} else {
/* maybe handle parameter expansion */
- exp_off = strcspn(var, ":-=+?%#");
- if (!var[exp_off])
- exp_off = 0;
- if (exp_off) {
- exp_save = var[exp_off];
- exp_null = exp_save == ':';
- exp_word = var + exp_off;
- if (exp_null)
- ++exp_word;
+ exp_saveptr = var + strcspn(var, ":-=+?%#");
+ exp_save = *exp_saveptr;
+ if (exp_save) {
+ exp_word = exp_saveptr;
+ if (exp_save == ':')
+ exp_word++;
exp_op = *exp_word++;
- var[exp_off] = '\0';
+ *exp_saveptr = '\0';
}
}
@@ -2615,7 +2613,7 @@ static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg, char
debug_printf_expand("expand: length of '%s' = ", val);
val = utoa(val ? strlen(val) : 0);
debug_printf_expand("%s\n", val);
- } else if (exp_off) {
+ } else if (exp_op) {
if (exp_op == '%' || exp_op == '#') {
if (val) {
/* we need to do a pattern match */
@@ -2623,7 +2621,7 @@ static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg, char
char *loc;
scan_t scan = pick_scan(exp_op, *exp_word, &match_at_left);
if (exp_op == *exp_word) /* ## or %% */
- ++exp_word;
+ exp_word++;
val = dyn_val = xstrdup(val);
loc = scan(dyn_val, exp_word, match_at_left);
if (match_at_left) /* # or ## */
@@ -2631,13 +2629,14 @@ static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg, char
else if (loc) /* % or %% and match was found */
*loc = '\0';
}
- } else {
+ } else { /* one of :-=+? */
+//TODO: handle ${VAR:N[:M]} here. N, M can be expressions similar to $((EXPR)): 2+2, 2+var etc
/* we need to do an expansion */
- int exp_test = (!val || (exp_null && !val[0]));
+ int exp_test = (!val || ((exp_save == ':') && !val[0]));
if (exp_op == '+')
exp_test = !exp_test;
debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
- exp_null ? "true" : "false", exp_test);
+ (exp_save == ':') ? "true" : "false", exp_test);
if (exp_test) {
if (exp_op == '?') {
//TODO: how interactive bash aborts expansion mid-command?
@@ -2666,7 +2665,7 @@ static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg, char
}
}
- var[exp_off] = exp_save;
+ *exp_saveptr = exp_save;
}
arg[0] = first_ch;