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-rw-r--r--shell/hush.c29
1 files changed, 16 insertions, 13 deletions
diff --git a/shell/hush.c b/shell/hush.c
index 920d9638c..3faf2b326 100644
--- a/shell/hush.c
+++ b/shell/hush.c
@@ -3800,8 +3800,8 @@ static int encode_string(o_string *as_string,
ch = i_getch(input); /* eat next */
if (ch == '\n')
goto again; /* skip \<newline> */
- } /* else: ch remains == '\\', and we double it */
- o_addqchr(dest, ch); /* \c if c is s glob char, else just c */
+ } /* else: ch remains == '\\', and we double it below: */
+ o_addqchr(dest, ch); /* \c if c is a glob char, else just c */
nommu_addchr(as_string, ch);
goto again;
}
@@ -4618,26 +4618,29 @@ static NOINLINE const char *expand_one_var(char **to_be_freed_pp, char *arg, cha
* Then var's value is matched to it and matching part removed.
*/
if (val && val[0]) {
+ char *t;
char *exp_exp_word;
char *loc;
unsigned scan_flags = pick_scan(exp_op, *exp_word);
if (exp_op == *exp_word) /* ## or %% */
exp_word++;
-//TODO: avoid xstrdup unless needed
-// (see HACK ALERT below for an example)
- val = to_be_freed = xstrdup(val);
exp_exp_word = encode_then_expand_string(exp_word, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
if (exp_exp_word)
exp_word = exp_exp_word;
- loc = scan_and_match(to_be_freed, exp_word, scan_flags);
+ /* HACK ALERT. We depend here on the fact that
+ * G.global_argv and results of utoa and get_local_var_value
+ * are actually in writable memory:
+ * scan_and_match momentarily stores NULs there. */
+ t = (char*)val;
+ loc = scan_and_match(t, exp_word, scan_flags);
//bb_error_msg("op:%c str:'%s' pat:'%s' res:'%s'",
- // exp_op, to_be_freed, exp_word, loc);
+ // exp_op, t, exp_word, loc);
free(exp_exp_word);
if (loc) { /* match was found */
if (scan_flags & SCAN_MATCH_LEFT_HALF) /* #[#] */
- val = loc;
+ val = loc; /* take right part */
else /* %[%] */
- *loc = '\0';
+ val = to_be_freed = xstrndup(val, loc - val); /* left */
}
}
}
@@ -4646,13 +4649,13 @@ static NOINLINE const char *expand_one_var(char **to_be_freed_pp, char *arg, cha
/* It's ${var/[/]pattern[/repl]} thing.
* Note that in encoded form it has TWO parts:
* var/pattern<SPECIAL_VAR_SYMBOL>repl<SPECIAL_VAR_SYMBOL>
+ * and if // is used, it is encoded as \:
+ * var\pattern<SPECIAL_VAR_SYMBOL>repl<SPECIAL_VAR_SYMBOL>
*/
/* Empty variable always gives nothing: */
// "v=''; echo ${v/*/w}" prints "", not "w"
if (val && val[0]) {
- /* It's ${var/[/]pattern[/repl]} thing */
- /*
- * Pattern is taken literally, while
+ /* pattern uses non-standard expansion.
* repl should be unbackslashed and globbed
* by the usual expansion rules:
* >az; >bz;
@@ -7339,7 +7342,7 @@ int hush_main(int argc, char **argv)
/* Deal with HUSH_VERSION */
G.shell_ver.flg_export = 1;
G.shell_ver.flg_read_only = 1;
- /* Code which handles ${var/P/R} needs writable values for all variables,
+ /* Code which handles ${var<op>...} needs writable values for all variables,
* therefore we xstrdup: */
G.shell_ver.varstr = xstrdup(hush_version_str),
G.top_var = &G.shell_ver;