hush: fix ${##}, ${#?}, ${#!} handling

function                                             old     new   delta
parse_dollar                                         786     820     +34
expand_one_var                                      1579    1592     +13
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 2/0 up/down: 47/0)               Total: 47 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

diff --git a/shell/ash_test/ash-vars/param_expand_alt.tests b/shell/ash_test/ash-vars/param_expand_alt.tests
index c9c4249aff1b70a75c82d403a1686c74ae5f993e..d80452434b8db7dfa76a32b53a25a91241ef956e 100755 (executable)
--- a/shell/ash_test/ash-vars/param_expand_alt.tests
+++ b/shell/ash_test/ash-vars/param_expand_alt.tests
@@ -6,7 +6,7 @@
 # now some funky ones.
 # ${V+word} "if V unset, then substitute nothing, else substitute word"
 # ${V:+word} "if V unset or '', then substitute nothing, else substitute word"
-# bash doesn't accept ${#+}. ash prints 0 (not $#).
+# bash doesn't accept ${#+}. ash prints 0 (not $#): "len of $+"
 echo _${#+}_ _${#:+}_
 # Forms with non-empty word work as expected in both ash and bash.
 echo _${#+z}_ _${#:+z}_

diff --git a/shell/ash_test/ash-vars/param_expand_len1.right b/shell/ash_test/ash-vars/param_expand_len1.right
new file mode 100644 (file)
index 0000000..dff3c7b
--- /dev/null
+++ b/shell/ash_test/ash-vars/param_expand_len1.right
@@ -0,0 +1,11 @@
+One:1
+Two:2
+Three:3
+
+One:1
+Two:2
+Three:3
+
+Ok ${#$}: 0
+
+Ok ${#!}: 0

diff --git a/shell/ash_test/ash-vars/param_expand_len1.tests b/shell/ash_test/ash-vars/param_expand_len1.tests
new file mode 100755 (executable)
index 0000000..e1beab3
--- /dev/null
+++ b/shell/ash_test/ash-vars/param_expand_len1.tests
@@ -0,0 +1,31 @@
+# ${#c} for any single char c means "length of $c", including all special vars
+
+false
+echo One:${#?}
+(exit 10)
+echo Two:${#?}
+(exit 100)
+echo Three:${#?}
+
+echo
+echo One:${##}
+set -- 1 2 3 4 5 6 7 8 9 0
+echo Two:${##}
+set -- 1 2 3 4 5 6 7 8 9 0  1 2 3 4 5 6 7 8 9 0  1 2 3 4 5 6 7 8 9 0 \
+       1 2 3 4 5 6 7 8 9 0  1 2 3 4 5 6 7 8 9 0  1 2 3 4 5 6 7 8 9 0 \
+       1 2 3 4 5 6 7 8 9 0  1 2 3 4 5 6 7 8 9 0  1 2 3 4 5 6 7 8 9 0 \
+       1 2 3 4 5 6 7 8 9 0  1 2 3 4 5 6 7 8 9 0  1 2 3 4 5 6 7 8 9 0
+echo Three:${##}
+
+echo
+v=$$
+test "${#v}" = "${#$}"
+echo 'Ok ${#$}:' $?
+
+echo
+sleep 0 &
+v=$!
+test "${#v}" = "${#!}"
+echo 'Ok ${#!}:' $?
+
+# TODO: ${#-} ${#_}

diff --git a/shell/hush.c b/shell/hush.c
index 11b33f40a4c4f9baed6ba2353d76b38c2fe1848e..d0225edb91a6be4853ec15fa3a4788cfcd1c39ca 100644 (file)
--- a/shell/hush.c
+++ b/shell/hush.c
@@ -4466,6 +4466,8 @@ static int parse_dollar(o_string *as_string,
        case '@': /* args */
                goto make_one_char_var;
        case '{': {
+               char len_single_ch;
+
                o_addchr(dest, SPECIAL_VAR_SYMBOL);
 
                ch = i_getch(input); /* eat '{' */
@@ -4485,6 +4487,7 @@ static int parse_dollar(o_string *as_string,
                        return 0;
                }
                nommu_addchr(as_string, ch);
+               len_single_ch = ch;
                ch |= quote_mask;
 
                /* It's possible to just call add_till_closing_bracket() at this point.
@@ -4509,9 +4512,18 @@ static int parse_dollar(o_string *as_string,
                                /* handle parameter expansions
                                 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
                                 */
-                               if (!strchr(VAR_SUBST_OPS, ch)) /* ${var<bad_char>... */
-                                       goto bad_dollar_syntax;
-
+                               if (!strchr(VAR_SUBST_OPS, ch)) { /* ${var<bad_char>... */
+                                       if (len_single_ch != '#'
+                                       /*|| !strchr(SPECIAL_VARS_STR, ch) - disallow errors like ${#+} ? */
+                                        || i_peek(input) != '}'
+                                       ) {
+                                               goto bad_dollar_syntax;
+                                       }
+                                       /* else: it's "length of C" ${#C} op,
+                                        * where C is a single char
+                                        * special var name, e.g. ${#!}.
+                                        */
+                               }
                                /* Eat everything until closing '}' (or ':') */
                                end_ch = '}';
                                if (BASH_SUBSTR
@@ -4568,6 +4580,7 @@ static int parse_dollar(o_string *as_string,
                                }
                                break;
                        }
+                       len_single_ch = 0; /* it can't be ${#C} op */
                }
                o_addchr(dest, SPECIAL_VAR_SYMBOL);
                break;
@@ -5559,10 +5572,10 @@ static NOINLINE const char *expand_one_var(char **to_be_freed_pp, char *arg, cha
        first_char = arg[0] = arg0 & 0x7f;
        exp_op = 0;
 
-       if (first_char == '#' && arg[1] /* ${#... but not ${#} */
-        && (!exp_saveptr               /* and (not ${#<op_char>...} */
-           || (arg[1] == '?' && arg[2] == '\0') /* or ${#?} - "len of $?") */
-           )
+       if (first_char == '#' && arg[1] /* ${#...} but not ${#} */
+        && (!exp_saveptr               /* and ( not(${#<op_char>...}) */
+           || (arg[2] == '\0' && strchr(SPECIAL_VARS_STR, arg[1])) /* or ${#C} "len of $C" ) */
+           )           /* NB: skipping ^^^specvar check mishandles ${#::2} */
        ) {
                /* It must be length operator: ${#var} */
                var++;

diff --git a/shell/hush_test/hush-vars/param_expand_alt.tests b/shell/hush_test/hush-vars/param_expand_alt.tests
index c9c4249aff1b70a75c82d403a1686c74ae5f993e..d80452434b8db7dfa76a32b53a25a91241ef956e 100755 (executable)
--- a/shell/hush_test/hush-vars/param_expand_alt.tests
+++ b/shell/hush_test/hush-vars/param_expand_alt.tests
@@ -6,7 +6,7 @@
 # now some funky ones.
 # ${V+word} "if V unset, then substitute nothing, else substitute word"
 # ${V:+word} "if V unset or '', then substitute nothing, else substitute word"
-# bash doesn't accept ${#+}. ash prints 0 (not $#).
+# bash doesn't accept ${#+}. ash prints 0 (not $#): "len of $+"
 echo _${#+}_ _${#:+}_
 # Forms with non-empty word work as expected in both ash and bash.
 echo _${#+z}_ _${#:+z}_

diff --git a/shell/hush_test/hush-vars/param_expand_len1.right b/shell/hush_test/hush-vars/param_expand_len1.right
new file mode 100644 (file)
index 0000000..dff3c7b
--- /dev/null
+++ b/shell/hush_test/hush-vars/param_expand_len1.right
@@ -0,0 +1,11 @@
+One:1
+Two:2
+Three:3
+
+One:1
+Two:2
+Three:3
+
+Ok ${#$}: 0
+
+Ok ${#!}: 0

diff --git a/shell/hush_test/hush-vars/param_expand_len1.tests b/shell/hush_test/hush-vars/param_expand_len1.tests
new file mode 100755 (executable)
index 0000000..e1beab3
--- /dev/null
+++ b/shell/hush_test/hush-vars/param_expand_len1.tests
@@ -0,0 +1,31 @@
+# ${#c} for any single char c means "length of $c", including all special vars
+
+false
+echo One:${#?}
+(exit 10)
+echo Two:${#?}
+(exit 100)
+echo Three:${#?}
+
+echo
+echo One:${##}
+set -- 1 2 3 4 5 6 7 8 9 0
+echo Two:${##}
+set -- 1 2 3 4 5 6 7 8 9 0  1 2 3 4 5 6 7 8 9 0  1 2 3 4 5 6 7 8 9 0 \
+       1 2 3 4 5 6 7 8 9 0  1 2 3 4 5 6 7 8 9 0  1 2 3 4 5 6 7 8 9 0 \
+       1 2 3 4 5 6 7 8 9 0  1 2 3 4 5 6 7 8 9 0  1 2 3 4 5 6 7 8 9 0 \
+       1 2 3 4 5 6 7 8 9 0  1 2 3 4 5 6 7 8 9 0  1 2 3 4 5 6 7 8 9 0
+echo Three:${##}
+
+echo
+v=$$
+test "${#v}" = "${#$}"
+echo 'Ok ${#$}:' $?
+
+echo
+sleep 0 &
+v=$!
+test "${#v}" = "${#!}"
+echo 'Ok ${#!}:' $?
+
+# TODO: ${#-} ${#_}