hush: handle expansions in ${var?expanded_word} constructs

function old new delta expand_vars_to_list 2209 2229 +20 Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
author: Denys Vlasenko <vda.linux@googlemail.com> 2010-05-21 17:54:46 +0200
committer: Denys Vlasenko <vda.linux@googlemail.com> 2010-05-21 17:54:46 +0200
commit: 3f78cec34745069cf0a92a16dfccff66d98ef5ba (patch)
tree: 1b2b8cd18d3ecfa92b9ae6b5fde3e66366da0cf7 /shell
parent: 349ef96bb5eae3c487884dd0e88c84a6ba0a1efa (diff)
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3 files changed, 62 insertions, 15 deletions
diff --git a/shell/hush.c b/shell/hush.c
index 1937d24e4..6d91a534a 100644
--- a/shell/hush.c
+++ b/shell/hush.c
@@ -2403,6 +2403,23 @@ static char *expand_pseudo_dquoted(const char *str)
        return exp_str;
 }
+#if ENABLE_SH_MATH_SUPPORT
+static arith_t expand_and_evaluate_arith(const char *arg, int *errcode_p)
+{
+        arith_eval_hooks_t hooks;
+        arith_t res;
+        char *exp_str;
+        hooks.lookupvar = get_local_var_value;
+        hooks.setvar = set_local_var_from_halves;
+        hooks.endofname = endofname;
+        exp_str = expand_pseudo_dquoted(arg);
+        res = arith(exp_str ? exp_str : arg, errcode_p, &hooks);
+        free(exp_str);
+        return res;
+}
+#endif
 /* Expand all variable references in given string, adding words to list[]
 * at n, n+1,... positions. Return updated n (so that list[n] is next one
 * to be filled). This routine is extremely tricky: has to deal with
@@ -2427,7 +2444,7 @@ static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg, char
        while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
                char first_ch;
                int i;
-                char *dyn_val = NULL;
+                char *to_be_freed = NULL;
                const char *val = NULL;
 #if ENABLE_HUSH_TICK
                o_string subst_result = NULL_O_STRING;
@@ -2528,21 +2545,13 @@ static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg, char
 #endif
 #if ENABLE_SH_MATH_SUPPORT
                case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
-                        arith_eval_hooks_t hooks;
                        arith_t res;
                        int errcode;
-                        char *exp_str;
                        arg++; /* skip '+' */
                        *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
                        debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
+                        res = expand_and_evaluate_arith(arg, &errcode);
-                        exp_str = expand_pseudo_dquoted(arg);
-                        hooks.lookupvar = get_local_var_value;
-                        hooks.setvar = set_local_var_from_halves;
-                        hooks.endofname = endofname;
-                        res = arith(exp_str ? exp_str : arg, &errcode, &hooks);
-                        free(exp_str);
                        if (errcode < 0) {
                                const char *msg = "error in arithmetic";
@@ -2628,8 +2637,8 @@ static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg, char
                                                scan_t scan = pick_scan(exp_op, *exp_word, &match_at_left);
                                                if (exp_op == *exp_word)        /* ## or %% */
                                                        exp_word++;
-                                                val = dyn_val = xstrdup(val);
+                                                val = to_be_freed = xstrdup(val);
-                                                loc = scan(dyn_val, exp_word, match_at_left);
+                                                loc = scan(to_be_freed, exp_word, match_at_left);
                                                if (match_at_left) /* # or ## */
                                                        val = loc;
                                                else if (loc) /* % or %% and match was found */
@@ -2662,7 +2671,7 @@ static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg, char
                                                if (len == 0 || !val || beg >= strlen(val))
                                                        val = "";
                                                else
-                                                        val = dyn_val = xstrndup(val + beg, len);
+                                                        val = to_be_freed = xstrndup(val + beg, len);
                                                //bb_error_msg("val:'%s'", val);
                                        } else
 #endif
@@ -2699,13 +2708,16 @@ static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg, char
                                        debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
                                                (exp_save == ':') ? "true" : "false", use_word);
                                        if (use_word) {
+                                                to_be_freed = expand_pseudo_dquoted(exp_word);
+                                                if (to_be_freed)
+                                                        exp_word = to_be_freed;
                                                if (exp_op == '?') {
-//TODO: how interactive bash aborts expansion mid-command?
                                                        /* mimic bash message */
                                                        die_if_script("%s: %s",
                                                                var,
                                                                exp_word[0] ? exp_word : "parameter null or not set"
                                                        );
+//TODO: how interactive bash aborts expansion mid-command?
                                                } else {
                                                        val = exp_word;
                                                }
@@ -2750,7 +2762,7 @@ static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg, char
                if (val) {
                        o_addQstr(output, val, strlen(val));
                }
-                free(dyn_val);
+                free(to_be_freed);
                /* Do the check to avoid writing to a const string */
                if (*p != SPECIAL_VAR_SYMBOL)
                        *p = SPECIAL_VAR_SYMBOL;
diff --git a/shell/hush_test/hush-vars/param_expand_indicate_error.right b/shell/hush_test/hush-vars/param_expand_indicate_error.right
index 590bb2001..06fcc5104 100644
--- a/shell/hush_test/hush-vars/param_expand_indicate_error.right
+++ b/shell/hush_test/hush-vars/param_expand_indicate_error.right
@@ -1,26 +1,41 @@
 hush: syntax error: unterminated ${name}
 0
 0
+====
 _
 hush: 1: parameter null or not set
 hush: 1: parameter null or not set
 hush: 1: message1
 hush: 1: message1
+hush: 1: unset!
+hush: 1: null or unset!
+====
 _aaaa
 _aaaa
 _aaaa
 _aaaa
 _aaaa
+_aaaa
+_aaaa
+====
 _
 hush: f: parameter null or not set
 hush: f: parameter null or not set
 hush: f: message3
 hush: f: message3
+hush: f: unset!
+hush: f: null or unset!
+====
 _
 _
 hush: f: parameter null or not set
 _
 hush: f: message4
+_
+hush: f: null or unset!
+====
+_fff
+_fff
 _fff
 _fff
 _fff
diff --git a/shell/hush_test/hush-vars/param_expand_indicate_error.tests b/shell/hush_test/hush-vars/param_expand_indicate_error.tests
index bccba3e1b..be14b1e37 100755
--- a/shell/hush_test/hush-vars/param_expand_indicate_error.tests
+++ b/shell/hush_test/hush-vars/param_expand_indicate_error.tests
@@ -5,36 +5,56 @@
 "$THIS_SH" -c 'echo ${:?}'
 # then some funky ones
+# note: bash prints 1 - treats it as "length of $#"? We print 0
 "$THIS_SH" -c 'echo ${#?}'
+# bash prints 0
 "$THIS_SH" -c 'echo ${#:?}'
 # now some valid ones
+export msg_unset="unset!"
+export msg_null_or_unset="null or unset!"
+echo ====
 "$THIS_SH" -c 'set --; echo _$1'
 "$THIS_SH" -c 'set --; echo _${1?}'
 "$THIS_SH" -c 'set --; echo _${1:?}'
 "$THIS_SH" -c 'set --; echo _${1?message1}'
 "$THIS_SH" -c 'set --; echo _${1:?message1}'
+"$THIS_SH" -c 'set --; echo _${1?$msg_unset}'
+"$THIS_SH" -c 'set --; echo _${1:?$msg_null_or_unset}'
+echo ====
 "$THIS_SH" -c 'set -- aaaa; echo _$1'
 "$THIS_SH" -c 'set -- aaaa; echo _${1?}'
 "$THIS_SH" -c 'set -- aaaa; echo _${1:?}'
 "$THIS_SH" -c 'set -- aaaa; echo _${1?word}'
 "$THIS_SH" -c 'set -- aaaa; echo _${1:?word}'
+"$THIS_SH" -c 'set -- aaaa; echo _${1?$msg_unset}'
+"$THIS_SH" -c 'set -- aaaa; echo _${1:?$msg_null_or_unset}'
+echo ====
 "$THIS_SH" -c 'unset f; echo _$f'
 "$THIS_SH" -c 'unset f; echo _${f?}'
 "$THIS_SH" -c 'unset f; echo _${f:?}'
 "$THIS_SH" -c 'unset f; echo _${f?message3}'
 "$THIS_SH" -c 'unset f; echo _${f:?message3}'
+"$THIS_SH" -c 'unset f; echo _${f?$msg_unset}'
+"$THIS_SH" -c 'unset f; echo _${f:?$msg_null_or_unset}'
+echo ====
 "$THIS_SH" -c 'f=; echo _$f'
 "$THIS_SH" -c 'f=; echo _${f?}'
 "$THIS_SH" -c 'f=; echo _${f:?}'
 "$THIS_SH" -c 'f=; echo _${f?word}'
 "$THIS_SH" -c 'f=; echo _${f:?message4}'
+"$THIS_SH" -c 'f=; echo _${f?$msg_unset}'
+"$THIS_SH" -c 'f=; echo _${f:?$msg_null_or_unset}'
+echo ====
 "$THIS_SH" -c 'f=fff; echo _$f'
 "$THIS_SH" -c 'f=fff; echo _${f?}'
 "$THIS_SH" -c 'f=fff; echo _${f:?}'
 "$THIS_SH" -c 'f=fff; echo _${f?word}'
 "$THIS_SH" -c 'f=fff; echo _${f:?word}'
+"$THIS_SH" -c 'f=fff; echo _${f?$msg_unset}'
+"$THIS_SH" -c 'f=fff; echo _${f:?$msg_null_or_unset}'
author	Denys Vlasenko <vda.linux@googlemail.com>	2010-05-21 17:54:46 +0200
committer	Denys Vlasenko <vda.linux@googlemail.com>	2010-05-21 17:54:46 +0200
commit	3f78cec34745069cf0a92a16dfccff66d98ef5ba (patch)
tree	1b2b8cd18d3ecfa92b9ae6b5fde3e66366da0cf7 /shell
parent	349ef96bb5eae3c487884dd0e88c84a6ba0a1efa (diff)
download	busybox-w32-3f78cec34745069cf0a92a16dfccff66d98ef5ba.tar.gz busybox-w32-3f78cec34745069cf0a92a16dfccff66d98ef5ba.tar.bz2 busybox-w32-3f78cec34745069cf0a92a16dfccff66d98ef5ba.zip

diff --git a/shell/hush.c b/shell/hush.c index 1937d24e4..6d91a534a 100644 --- a/shell/hush.c +++ b/shell/hush.c
@@ -2403,6 +2403,23 @@ static char expand_pseudo_dquoted(const char str)
2403	return exp_str;	2403	return exp_str;
2404	}	2404	}
2405		2405
		2406	#if ENABLE_SH_MATH_SUPPORT
		2407	static arith_t expand_and_evaluate_arith(const char arg, int errcode_p)
		2408	{
		2409	arith_eval_hooks_t hooks;
		2410	arith_t res;
		2411	char *exp_str;
		2412
		2413	hooks.lookupvar = get_local_var_value;
		2414	hooks.setvar = set_local_var_from_halves;
		2415	hooks.endofname = endofname;
		2416	exp_str = expand_pseudo_dquoted(arg);
		2417	res = arith(exp_str ? exp_str : arg, errcode_p, &hooks);
		2418	free(exp_str);
		2419	return res;
		2420	}
		2421	#endif
		2422
2406	/* Expand all variable references in given string, adding words to list[]	2423	/* Expand all variable references in given string, adding words to list[]
2407	* at n, n+1,... positions. Return updated n (so that list[n] is next one	2424	* at n, n+1,... positions. Return updated n (so that list[n] is next one
2408	* to be filled). This routine is extremely tricky: has to deal with	2425	* to be filled). This routine is extremely tricky: has to deal with
@@ -2427,7 +2444,7 @@ static NOINLINE int expand_vars_to_list(o_string output, int n, char arg, char
2427	while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {	2444	while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
2428	char first_ch;	2445	char first_ch;
2429	int i;	2446	int i;
2430	char *dyn_val = NULL;	2447	char *to_be_freed = NULL;
2431	const char *val = NULL;	2448	const char *val = NULL;
2432	#if ENABLE_HUSH_TICK	2449	#if ENABLE_HUSH_TICK
2433	o_string subst_result = NULL_O_STRING;	2450	o_string subst_result = NULL_O_STRING;
@@ -2528,21 +2545,13 @@ static NOINLINE int expand_vars_to_list(o_string output, int n, char arg, char
2528	#endif	2545	#endif
2529	#if ENABLE_SH_MATH_SUPPORT	2546	#if ENABLE_SH_MATH_SUPPORT
2530	case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */	2547	case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
2531	arith_eval_hooks_t hooks;
2532	arith_t res;	2548	arith_t res;
2533	int errcode;	2549	int errcode;
2534	char *exp_str;
2535		2550
2536	arg++; /* skip '+' */	2551	arg++; /* skip '+' */
2537	p = '\0'; / replace trailing <SPECIAL_VAR_SYMBOL> */	2552	p = '\0'; / replace trailing <SPECIAL_VAR_SYMBOL> */
2538	debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);	2553	debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
2539		2554	res = expand_and_evaluate_arith(arg, &errcode);
2540	exp_str = expand_pseudo_dquoted(arg);
2541	hooks.lookupvar = get_local_var_value;
2542	hooks.setvar = set_local_var_from_halves;
2543	hooks.endofname = endofname;
2544	res = arith(exp_str ? exp_str : arg, &errcode, &hooks);
2545	free(exp_str);
2546		2555
2547	if (errcode < 0) {	2556	if (errcode < 0) {
2548	const char *msg = "error in arithmetic";	2557	const char *msg = "error in arithmetic";
@@ -2628,8 +2637,8 @@ static NOINLINE int expand_vars_to_list(o_string output, int n, char arg, char
2628	scan_t scan = pick_scan(exp_op, *exp_word, &match_at_left);	2637	scan_t scan = pick_scan(exp_op, *exp_word, &match_at_left);
2629	if (exp_op == exp_word) / ## or %% */	2638	if (exp_op == exp_word) / ## or %% */
2630	exp_word++;	2639	exp_word++;
2631	val = dyn_val = xstrdup(val);	2640	val = to_be_freed = xstrdup(val);
2632	loc = scan(dyn_val, exp_word, match_at_left);	2641	loc = scan(to_be_freed, exp_word, match_at_left);
2633	if (match_at_left) /* # or ## */	2642	if (match_at_left) /* # or ## */
2634	val = loc;	2643	val = loc;
2635	else if (loc) /* % or %% and match was found */	2644	else if (loc) /* % or %% and match was found */
@@ -2662,7 +2671,7 @@ static NOINLINE int expand_vars_to_list(o_string output, int n, char arg, char
2662	if (len == 0 \|\| !val \|\| beg >= strlen(val))	2671	if (len == 0 \|\| !val \|\| beg >= strlen(val))
2663	val = "";	2672	val = "";
2664	else	2673	else
2665	val = dyn_val = xstrndup(val + beg, len);	2674	val = to_be_freed = xstrndup(val + beg, len);
2666	//bb_error_msg("val:'%s'", val);	2675	//bb_error_msg("val:'%s'", val);
2667	} else	2676	} else
2668	#endif	2677	#endif
@@ -2699,13 +2708,16 @@ static NOINLINE int expand_vars_to_list(o_string output, int n, char arg, char
2699	debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,	2708	debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
2700	(exp_save == ':') ? "true" : "false", use_word);	2709	(exp_save == ':') ? "true" : "false", use_word);
2701	if (use_word) {	2710	if (use_word) {
		2711	to_be_freed = expand_pseudo_dquoted(exp_word);
		2712	if (to_be_freed)
		2713	exp_word = to_be_freed;
2702	if (exp_op == '?') {	2714	if (exp_op == '?') {
2703	//TODO: how interactive bash aborts expansion mid-command?
2704	/* mimic bash message */	2715	/* mimic bash message */
2705	die_if_script("%s: %s",	2716	die_if_script("%s: %s",
2706	var,	2717	var,
2707	exp_word[0] ? exp_word : "parameter null or not set"	2718	exp_word[0] ? exp_word : "parameter null or not set"
2708	);	2719	);
		2720	//TODO: how interactive bash aborts expansion mid-command?
2709	} else {	2721	} else {
2710	val = exp_word;	2722	val = exp_word;
2711	}	2723	}
@@ -2750,7 +2762,7 @@ static NOINLINE int expand_vars_to_list(o_string output, int n, char arg, char
2750	if (val) {	2762	if (val) {
2751	o_addQstr(output, val, strlen(val));	2763	o_addQstr(output, val, strlen(val));
2752	}	2764	}
2753	free(dyn_val);	2765	free(to_be_freed);
2754	/* Do the check to avoid writing to a const string */	2766	/* Do the check to avoid writing to a const string */
2755	if (*p != SPECIAL_VAR_SYMBOL)	2767	if (*p != SPECIAL_VAR_SYMBOL)
2756	*p = SPECIAL_VAR_SYMBOL;	2768	*p = SPECIAL_VAR_SYMBOL;


diff --git a/shell/hush_test/hush-vars/param_expand_indicate_error.right b/shell/hush_test/hush-vars/param_expand_indicate_error.right index 590bb2001..06fcc5104 100644 --- a/shell/hush_test/hush-vars/param_expand_indicate_error.right +++ b/shell/hush_test/hush-vars/param_expand_indicate_error.right
@@ -1,26 +1,41 @@
1	hush: syntax error: unterminated ${name}	1	hush: syntax error: unterminated ${name}
2	0	2	0
3	0	3	0
		4	====
4	_	5	_
5	hush: 1: parameter null or not set	6	hush: 1: parameter null or not set
6	hush: 1: parameter null or not set	7	hush: 1: parameter null or not set
7	hush: 1: message1	8	hush: 1: message1
8	hush: 1: message1	9	hush: 1: message1
		10	hush: 1: unset!
		11	hush: 1: null or unset!
		12	====
9	_aaaa	13	_aaaa
10	_aaaa	14	_aaaa
11	_aaaa	15	_aaaa
12	_aaaa	16	_aaaa
13	_aaaa	17	_aaaa
		18	_aaaa
		19	_aaaa
		20	====
14	_	21	_
15	hush: f: parameter null or not set	22	hush: f: parameter null or not set
16	hush: f: parameter null or not set	23	hush: f: parameter null or not set
17	hush: f: message3	24	hush: f: message3
18	hush: f: message3	25	hush: f: message3
		26	hush: f: unset!
		27	hush: f: null or unset!
		28	====
19	_	29	_
20	_	30	_
21	hush: f: parameter null or not set	31	hush: f: parameter null or not set
22	_	32	_
23	hush: f: message4	33	hush: f: message4
		34	_
		35	hush: f: null or unset!
		36	====
		37	_fff
		38	_fff
24	_fff	39	_fff
25	_fff	40	_fff
26	_fff	41	_fff


diff --git a/shell/hush_test/hush-vars/param_expand_indicate_error.tests b/shell/hush_test/hush-vars/param_expand_indicate_error.tests index bccba3e1b..be14b1e37 100755 --- a/shell/hush_test/hush-vars/param_expand_indicate_error.tests +++ b/shell/hush_test/hush-vars/param_expand_indicate_error.tests
@@ -5,36 +5,56 @@
5	"$THIS_SH" -c 'echo ${:?}'	5	"$THIS_SH" -c 'echo ${:?}'
6		6
7	# then some funky ones	7	# then some funky ones
		8	# note: bash prints 1 - treats it as "length of $#"? We print 0
8	"$THIS_SH" -c 'echo ${#?}'	9	"$THIS_SH" -c 'echo ${#?}'
		10	# bash prints 0
9	"$THIS_SH" -c 'echo ${#:?}'	11	"$THIS_SH" -c 'echo ${#:?}'
10		12
11	# now some valid ones	13	# now some valid ones
		14	export msg_unset="unset!"
		15	export msg_null_or_unset="null or unset!"
		16
		17	echo ====
12	"$THIS_SH" -c 'set --; echo _$1'	18	"$THIS_SH" -c 'set --; echo _$1'
13	"$THIS_SH" -c 'set --; echo _${1?}'	19	"$THIS_SH" -c 'set --; echo _${1?}'
14	"$THIS_SH" -c 'set --; echo _${1:?}'	20	"$THIS_SH" -c 'set --; echo _${1:?}'
15	"$THIS_SH" -c 'set --; echo _${1?message1}'	21	"$THIS_SH" -c 'set --; echo _${1?message1}'
16	"$THIS_SH" -c 'set --; echo _${1:?message1}'	22	"$THIS_SH" -c 'set --; echo _${1:?message1}'
		23	"$THIS_SH" -c 'set --; echo _${1?$msg_unset}'
		24	"$THIS_SH" -c 'set --; echo _${1:?$msg_null_or_unset}'
17		25
		26	echo ====
18	"$THIS_SH" -c 'set -- aaaa; echo _$1'	27	"$THIS_SH" -c 'set -- aaaa; echo _$1'
19	"$THIS_SH" -c 'set -- aaaa; echo _${1?}'	28	"$THIS_SH" -c 'set -- aaaa; echo _${1?}'
20	"$THIS_SH" -c 'set -- aaaa; echo _${1:?}'	29	"$THIS_SH" -c 'set -- aaaa; echo _${1:?}'
21	"$THIS_SH" -c 'set -- aaaa; echo _${1?word}'	30	"$THIS_SH" -c 'set -- aaaa; echo _${1?word}'
22	"$THIS_SH" -c 'set -- aaaa; echo _${1:?word}'	31	"$THIS_SH" -c 'set -- aaaa; echo _${1:?word}'
		32	"$THIS_SH" -c 'set -- aaaa; echo _${1?$msg_unset}'
		33	"$THIS_SH" -c 'set -- aaaa; echo _${1:?$msg_null_or_unset}'
23		34
		35	echo ====
24	"$THIS_SH" -c 'unset f; echo _$f'	36	"$THIS_SH" -c 'unset f; echo _$f'
25	"$THIS_SH" -c 'unset f; echo _${f?}'	37	"$THIS_SH" -c 'unset f; echo _${f?}'
26	"$THIS_SH" -c 'unset f; echo _${f:?}'	38	"$THIS_SH" -c 'unset f; echo _${f:?}'
27	"$THIS_SH" -c 'unset f; echo _${f?message3}'	39	"$THIS_SH" -c 'unset f; echo _${f?message3}'
28	"$THIS_SH" -c 'unset f; echo _${f:?message3}'	40	"$THIS_SH" -c 'unset f; echo _${f:?message3}'
		41	"$THIS_SH" -c 'unset f; echo _${f?$msg_unset}'
		42	"$THIS_SH" -c 'unset f; echo _${f:?$msg_null_or_unset}'
29		43
		44	echo ====
30	"$THIS_SH" -c 'f=; echo _$f'	45	"$THIS_SH" -c 'f=; echo _$f'
31	"$THIS_SH" -c 'f=; echo _${f?}'	46	"$THIS_SH" -c 'f=; echo _${f?}'
32	"$THIS_SH" -c 'f=; echo _${f:?}'	47	"$THIS_SH" -c 'f=; echo _${f:?}'
33	"$THIS_SH" -c 'f=; echo _${f?word}'	48	"$THIS_SH" -c 'f=; echo _${f?word}'
34	"$THIS_SH" -c 'f=; echo _${f:?message4}'	49	"$THIS_SH" -c 'f=; echo _${f:?message4}'
		50	"$THIS_SH" -c 'f=; echo _${f?$msg_unset}'
		51	"$THIS_SH" -c 'f=; echo _${f:?$msg_null_or_unset}'
35		52
		53	echo ====
36	"$THIS_SH" -c 'f=fff; echo _$f'	54	"$THIS_SH" -c 'f=fff; echo _$f'
37	"$THIS_SH" -c 'f=fff; echo _${f?}'	55	"$THIS_SH" -c 'f=fff; echo _${f?}'
38	"$THIS_SH" -c 'f=fff; echo _${f:?}'	56	"$THIS_SH" -c 'f=fff; echo _${f:?}'
39	"$THIS_SH" -c 'f=fff; echo _${f?word}'	57	"$THIS_SH" -c 'f=fff; echo _${f?word}'
40	"$THIS_SH" -c 'f=fff; echo _${f:?word}'	58	"$THIS_SH" -c 'f=fff; echo _${f:?word}'
		59	"$THIS_SH" -c 'f=fff; echo _${f?$msg_unset}'
		60	"$THIS_SH" -c 'f=fff; echo _${f:?$msg_null_or_unset}'