feat(rc): string concatenation works

7 files changed, 162 insertions, 115 deletions

diff --git a/sys/cmd/rc/code.c b/sys/cmd/rc/code.c
index c5b1987..70fe818 100644
--- a/sys/cmd/rc/code.c
+++ b/sys/cmd/rc/code.c
@@ -77,7 +77,6 @@ walk(Tree *node)
         walk(node->child[1]);
         break;
 
-#if 0
     case '^':
         emitf(Xmark);
         walk(node->child[1]);
@@ -85,7 +84,6 @@ walk(Tree *node)
         walk(node->child[0]);
         emitf(Xconcatenate);
         break;
-#endif
 
     case Targs:
         walk(node->child[1]);
diff --git a/sys/cmd/rc/exec.c b/sys/cmd/rc/exec.c
index 6d0c0a9..ac0dc08 100644
--- a/sys/cmd/rc/exec.c
+++ b/sys/cmd/rc/exec.c
@@ -578,6 +578,52 @@ Xword(void)
     pushword(runner->code.exe[runner->code.i++].s);
 }
 
+static
+Word*
+catlist(Word *l, Word *r, Word *tail)
+{
+    Word *w;
+    char *buf;
+
+    if(l->link || r->link)
+        tail = catlist( (!l->link)?l:l->link, (!r->link)?r:r->link, tail);
+
+    buf = emalloc(strlen(l->str)+strlen(r->str)+1);
+    strcpy(buf, l->str);
+    strcat(buf, r->str);
+
+    w = makeword(buf, tail);
+    efree(buf);
+
+    return w;
+}
+
+void
+Xconcatenate(void)
+{
+    int rn, ln;
+    Word *l = runner->args->word;
+    Word *r = runner->args->link->word;
+    Word *w = runner->args->link->link->word;
+
+    ln = count(l), rn = count(r);
+    if(ln != 0 || rn != 0) {
+        if(ln == 0 || rn == 0){
+            Xerror("null list in concatenation\n");
+            return;
+        }
+        if(ln != 1 && rn != 1 && ln != rn) {
+            Xerror("mismatched list lengths in concatenation\n");
+            return;
+        }
+        w = catlist(l, r, w);
+    }
+
+    poplist();
+    poplist();
+    runner->args->word = w;
+}
+
 void
 Xdollar(void)
 {
@@ -638,7 +684,6 @@ Xassign(void)
     poplist();
 }
 
-
 void
 Xreadcmd(void)
 {
@@ -982,8 +1027,6 @@ Xreturn(void)
         exit(0);
 }
 
-
-
 void
 Xexit(void)
 {
diff --git a/sys/cmd/rc/exec.h b/sys/cmd/rc/exec.h
index f85c699..d018fed 100644
--- a/sys/cmd/rc/exec.h
+++ b/sys/cmd/rc/exec.h
@@ -20,6 +20,7 @@ void Xasync(void);
 void Xbasic(void);     // Xbasic(args) run command and wait for result
 void Xsubshell(void);
 void Xword(void);
+void Xconcatenate(void);
 void Xcount(void);
 void Xflat(void);
 void Xpipe(void);
diff --git a/sys/cmd/rc/lex.c b/sys/cmd/rc/lex.c
index 31c7cdc..8ddf270 100644
--- a/sys/cmd/rc/lex.c
+++ b/sys/cmd/rc/lex.c
@@ -33,6 +33,9 @@ yyerror(const char *msg)
     print(shell.err, "%s\n", msg);
     flush(shell.err);
 
+    lexer.hadword   = 0;
+    lexer.haddollar = 0;
+
     /* consume remaining tokens */
     while(lexer.c[0] !='\n' && lexer.c[0] != EOF)
         advance();
@@ -193,6 +196,7 @@ yylex(void)
 
     /* inject tokens */
     if(lexer.hadword){
+        lexer.hadword = 0;
         if(d=='('){
             advance();
             strcpy(lexer.buf, "( [Tindex]");
diff --git a/sys/cmd/rc/parse.c b/sys/cmd/rc/parse.c
index edc1006..731c244 100644
--- a/sys/cmd/rc/parse.c
+++ b/sys/cmd/rc/parse.c
@@ -124,17 +124,17 @@ enum yysymbol_kind_t
   YYSYMBOL_Tindex = 19,                    /* Tindex  */
   YYSYMBOL_Twhile = 20,                    /* Twhile  */
   YYSYMBOL_21_n_ = 21,                     /* '\n'  */
-  YYSYMBOL_22_ = 22,                       /* '$'  */
-  YYSYMBOL_Tcount = 23,                    /* Tcount  */
-  YYSYMBOL_Tflat = 24,                     /* Tflat  */
-  YYSYMBOL_25_ = 25,                       /* '('  */
-  YYSYMBOL_26_ = 26,                       /* ')'  */
-  YYSYMBOL_27_ = 27,                       /* '{'  */
-  YYSYMBOL_28_ = 28,                       /* '}'  */
-  YYSYMBOL_29_ = 29,                       /* ';'  */
-  YYSYMBOL_30_ = 30,                       /* '&'  */
-  YYSYMBOL_31_ = 31,                       /* '='  */
-  YYSYMBOL_32_ = 32,                       /* '^'  */
+  YYSYMBOL_22_ = 22,                       /* '^'  */
+  YYSYMBOL_23_ = 23,                       /* '$'  */
+  YYSYMBOL_Tcount = 24,                    /* Tcount  */
+  YYSYMBOL_Tflat = 25,                     /* Tflat  */
+  YYSYMBOL_26_ = 26,                       /* '('  */
+  YYSYMBOL_27_ = 27,                       /* ')'  */
+  YYSYMBOL_28_ = 28,                       /* '{'  */
+  YYSYMBOL_29_ = 29,                       /* '}'  */
+  YYSYMBOL_30_ = 30,                       /* ';'  */
+  YYSYMBOL_31_ = 31,                       /* '&'  */
+  YYSYMBOL_32_ = 32,                       /* '='  */
   YYSYMBOL_YYACCEPT = 33,                  /* $accept  */
   YYSYMBOL_rc = 34,                        /* rc  */
   YYSYMBOL_line = 35,                      /* line  */
@@ -483,7 +483,7 @@ union yyalloc
 /* YYFINAL -- State number of the termination state.  */
 #define YYFINAL  42
 /* YYLAST -- Last index in YYTABLE.  */
-#define YYLAST   158
+#define YYLAST   155
 
 /* YYNTOKENS -- Number of terminals.  */
 #define YYNTOKENS  33
@@ -512,16 +512,16 @@ static const yytype_int8 yytranslate[] =
        0,     2,     2,     2,     2,     2,     2,     2,     2,     2,
       21,     2,     2,     2,     2,     2,     2,     2,     2,     2,
        2,     2,     2,     2,     2,     2,     2,     2,     2,     2,
-       2,     2,     2,     2,     2,     2,    22,     2,    30,     2,
-      25,    26,     2,     2,     2,     2,     2,     2,     2,     2,
-       2,     2,     2,     2,     2,     2,     2,     2,     2,    29,
-       2,    31,     2,     2,     2,     2,     2,     2,     2,     2,
+       2,     2,     2,     2,     2,     2,    23,     2,    31,     2,
+      26,    27,     2,     2,     2,     2,     2,     2,     2,     2,
+       2,     2,     2,     2,     2,     2,     2,     2,     2,    30,
+       2,    32,     2,     2,     2,     2,     2,     2,     2,     2,
        2,     2,     2,     2,     2,     2,     2,     2,     2,     2,
        2,     2,     2,     2,     2,     2,     2,     2,     2,     2,
-       2,     2,     2,     2,    32,     2,     2,     2,     2,     2,
+       2,     2,     2,     2,    22,     2,     2,     2,     2,     2,
        2,     2,     2,     2,     2,     2,     2,     2,     2,     2,
        2,     2,     2,     2,     2,     2,     2,     2,     2,     2,
-       2,     2,     2,    27,     2,    28,     2,     2,     2,     2,
+       2,     2,     2,    28,     2,    29,     2,     2,     2,     2,
        2,     2,     2,     2,     2,     2,     2,     2,     2,     2,
        2,     2,     2,     2,     2,     2,     2,     2,     2,     2,
        2,     2,     2,     2,     2,     2,     2,     2,     2,     2,
@@ -536,19 +536,19 @@ static const yytype_int8 yytranslate[] =
        2,     2,     2,     2,     2,     2,     2,     2,     2,     2,
        2,     2,     2,     2,     2,     2,     1,     2,     3,     4,
        5,     6,     7,     8,     9,    10,    11,    12,    13,    14,
-      15,    16,    17,    18,    19,    20,    23,    24
+      15,    16,    17,    18,    19,    20,    24,    25
 };
 
 #if YYDEBUG
 /* YYRLINE[YYN] -- Source line where rule number YYN was defined.  */
-static const yytype_int8 yyrline[] =
+static const yytype_uint8 yyrline[] =
 {
-       0,    37,    37,    38,    41,    42,    45,    46,    49,    52,
-      55,    56,    59,    60,    63,    64,    67,    70,    71,    74,
-      75,    78,    79,    80,    81,    82,    83,    84,    85,    86,
-      89,    90,    91,    94,    95,    98,    99,   102,   103,   106,
-     107,   108,   109,   110,   114,   114,   114,   114,   121,   122,
-     123,   125,   127
+       0,    38,    38,    39,    42,    43,    46,    47,    50,    53,
+      56,    57,    60,    61,    64,    65,    68,    71,    72,    75,
+      76,    79,    80,    81,    82,    83,    84,    85,    86,    87,
+      90,    91,    92,    95,    96,    99,   100,   103,   104,   107,
+     108,   109,   110,   111,   115,   115,   115,   115,   122,   123,
+     124,   126,   128
 };
 #endif
 
@@ -567,8 +567,8 @@ static const char *const yytname[] =
   "\"end of file\"", "error", "\"invalid token\"", "Tword", "Twords",
   "Tif", "Telse", "Tbang", "Tsubshell", "Toror", "Tandand", "There",
   "Tredir", "Tpipe", "Tdup", "Tbasic", "Tparen", "Tblock", "Targs",
-  "Tindex", "Twhile", "'\\n'", "'$'", "Tcount", "Tflat", "'('", "')'",
-  "'{'", "'}'", "';'", "'&'", "'='", "'^'", "$accept", "rc", "line",
+  "Tindex", "Twhile", "'\\n'", "'^'", "'$'", "Tcount", "Tflat", "'('",
+  "')'", "'{'", "'}'", "';'", "'&'", "'='", "$accept", "rc", "line",
   "body", "paren", "block", "cmds", "cmdsln", "ifbody", "assign", "redir",
   "epilog", "cmd", "basic", "atom", "word", "executable", "nonkeyword",
   "keyword", "wordsnl", "nl", YY_NULLPTR
@@ -595,14 +595,14 @@ yysymbol_name (yysymbol_kind_t yysymbol)
    STATE-NUM.  */
 static const yytype_int16 yypact[] =
 {
-      22,   -42,   -23,    89,    89,   133,   -42,   133,   133,   133,
-     -42,    89,    18,     7,    -5,    89,    89,    89,    24,   123,
-      20,   -42,    89,   -42,    25,    25,   -42,   -42,   -42,   -42,
-     -42,    23,   -42,   -42,   -42,   -42,   -42,    99,    15,   -42,
-      89,    35,   -42,   -42,    -5,   -42,   -42,    25,    25,   -42,
-     -42,   -42,   -42,    23,   133,   133,    36,    66,   133,   -42,
-     -42,    23,   -42,   -42,   -42,   -42,    66,    23,   -42,   -42,
-     -42,    27,   -42,    25,   -42,   -42,   -42,    66,    25
+      22,   -42,   -24,    75,    75,   129,   -42,   129,   129,   129,
+     -42,    75,    26,   -10,    -5,    75,    75,    75,     8,   105,
+      32,   -42,    75,   -42,    19,    19,   -42,   -42,   -42,   -42,
+     -42,    18,   -42,   -42,   -42,   -42,   -42,    99,     4,   -42,
+      75,    31,   -42,   -42,    -5,   -42,   -42,    19,    19,   -42,
+     -42,   -42,   -42,    18,   129,   129,    24,    67,   129,   -42,
+     -42,    18,   -42,   -42,   -42,   -42,    67,   -42,    18,   -42,
+     -42,   127,   -42,    19,   -42,   -42,   -42,    67,    19
 };
 
 /* YYDEFACT[STATE-NUM] -- Default reduction number in state STATE-NUM.
@@ -616,15 +616,15 @@ static const yytype_int8 yydefact[] =
       35,    18,    33,    34,    40,    42,    43,     0,     0,    12,
       21,     6,     1,     3,    19,    23,     5,    26,    25,    51,
       10,    11,    32,    31,     0,     0,     0,    21,     0,    49,
-      41,    50,     9,     7,    13,    20,    21,    16,    38,     8,
+      41,    50,     9,     7,    13,    20,    21,    38,    16,     8,
       52,    19,    27,    14,    36,    24,    51,    21,    15
 };
 
 /* YYPGOTO[NTERM-NUM].  */
 static const yytype_int8 yypgoto[] =
 {
-     -42,   -42,    46,    10,   -42,    19,    11,   -42,   -42,   -42,
-     -13,    28,     0,   -42,    12,   -14,   -42,     5,   -42,   -42,
+     -42,   -42,    34,    15,   -42,    -4,    28,   -42,   -42,   -42,
+     -13,    12,     0,   -42,    11,   -14,   -42,     5,   -42,   -42,
      -41
 };
 
@@ -642,54 +642,54 @@ static const yytype_int8 yydefgoto[] =
 static const yytype_int8 yytable[] =
 {
       18,    44,    22,    24,    25,    53,    52,     5,    66,     6,
-      32,    15,    32,    32,    32,    18,    47,    48,    42,    34,
-      35,    36,    -2,    61,    32,     1,    15,     2,    43,     3,
-       4,    44,    56,    76,     5,    77,     6,    49,    49,     5,
-      67,     6,    32,    62,     7,     8,     9,    10,    49,    11,
-      63,    54,    55,    50,    51,    58,    64,    73,    44,    32,
-      32,    46,    69,    32,    50,    51,    75,    68,     0,     1,
-      74,     2,    65,     3,     4,     0,    71,    78,     5,     0,
-       6,     0,     0,     0,     0,     0,     0,    70,     7,     8,
-       9,    10,     1,    11,     2,     0,     3,     4,     0,     0,
-       0,     5,     1,     6,    26,    27,    28,    29,     0,     0,
-       0,     7,     8,     9,    10,     0,    11,     0,     0,     0,
-      59,     7,     8,     9,    10,    60,     1,     0,    26,    27,
-      28,    29,     0,     0,     0,     5,     1,     6,    26,    27,
-      28,    29,     0,     0,     0,     7,     8,     9,    10,     0,
-       0,     0,     0,     0,     0,     7,     8,     9,    10
+      32,    43,    32,    32,    32,    18,    47,    48,    34,    35,
+      36,    49,    -2,    61,    32,     1,    42,     2,    15,     3,
+       4,    44,    49,    62,     5,    77,     6,    56,    50,    51,
+      58,    68,    32,    15,    49,     7,     8,     9,    10,    46,
+      11,    69,    64,    71,    54,    63,    65,    73,    44,    32,
+      32,    50,    51,    32,    55,    67,    75,     0,     0,    74,
+       1,     0,     2,     0,     3,     4,     0,    78,     1,     5,
+       2,     6,     3,     4,     0,     0,     0,     5,    70,     6,
+       7,     8,     9,    10,     0,    11,     0,     0,     7,     8,
+       9,    10,     1,    11,    26,    27,    28,    29,     1,     0,
+      26,    27,    28,    29,     0,     0,     0,     5,     0,     6,
+      59,     0,     7,     8,     9,    10,    60,     0,     7,     8,
+       9,    10,     1,    76,    26,    27,    28,    29,     0,     5,
+       0,     6,     0,     0,     0,     0,     0,     0,     0,     0,
+       0,     0,     7,     8,     9,    10
 };
 
 static const yytype_int8 yycheck[] =
 {
-       0,    14,    25,     3,     4,    19,    19,    12,    49,    14,
-       5,     0,     7,     8,     9,    15,    16,    17,     0,     7,
-       8,     9,     0,    37,    19,     3,    15,     5,    21,     7,
-       8,    44,    22,     6,    12,    76,    14,    13,    13,    12,
-      54,    14,    37,    28,    22,    23,    24,    25,    13,    27,
-      40,    31,    32,    29,    30,    32,    21,    57,    71,    54,
-      55,    15,    26,    58,    29,    30,    66,    55,    -1,     3,
-      58,     5,    44,     7,     8,    -1,    57,    77,    12,    -1,
-      14,    -1,    -1,    -1,    -1,    -1,    -1,    21,    22,    23,
-      24,    25,     3,    27,     5,    -1,     7,     8,    -1,    -1,
-      -1,    12,     3,    14,     5,     6,     7,     8,    -1,    -1,
-      -1,    22,    23,    24,    25,    -1,    27,    -1,    -1,    -1,
-      21,    22,    23,    24,    25,    26,     3,    -1,     5,     6,
-       7,     8,    -1,    -1,    -1,    12,     3,    14,     5,     6,
-       7,     8,    -1,    -1,    -1,    22,    23,    24,    25,    -1,
-      -1,    -1,    -1,    -1,    -1,    22,    23,    24,    25
+       0,    14,    26,     3,     4,    19,    19,    12,    49,    14,
+       5,    21,     7,     8,     9,    15,    16,    17,     7,     8,
+       9,    13,     0,    37,    19,     3,     0,     5,     0,     7,
+       8,    44,    13,    29,    12,    76,    14,    22,    30,    31,
+      22,    55,    37,    15,    13,    23,    24,    25,    26,    15,
+      28,    27,    21,    57,    22,    40,    44,    57,    71,    54,
+      55,    30,    31,    58,    32,    54,    66,    -1,    -1,    58,
+       3,    -1,     5,    -1,     7,     8,    -1,    77,     3,    12,
+       5,    14,     7,     8,    -1,    -1,    -1,    12,    21,    14,
+      23,    24,    25,    26,    -1,    28,    -1,    -1,    23,    24,
+      25,    26,     3,    28,     5,     6,     7,     8,     3,    -1,
+       5,     6,     7,     8,    -1,    -1,    -1,    12,    -1,    14,
+      21,    -1,    23,    24,    25,    26,    27,    -1,    23,    24,
+      25,    26,     3,     6,     5,     6,     7,     8,    -1,    12,
+      -1,    14,    -1,    -1,    -1,    -1,    -1,    -1,    -1,    -1,
+      -1,    -1,    23,    24,    25,    26
 };
 
 /* YYSTOS[STATE-NUM] -- The symbol kind of the accessing symbol of
    state STATE-NUM.  */
 static const yytype_int8 yystos[] =
 {
-       0,     3,     5,     7,     8,    12,    14,    22,    23,    24,
-      25,    27,    34,    35,    38,    39,    42,    43,    45,    46,
-      49,    50,    25,    37,    45,    45,     5,     6,     7,     8,
+       0,     3,     5,     7,     8,    12,    14,    23,    24,    25,
+      26,    28,    34,    35,    38,    39,    42,    43,    45,    46,
+      49,    50,    26,    37,    45,    45,     5,     6,     7,     8,
       47,    48,    50,    51,    47,    47,    47,    52,    36,    39,
       40,    45,     0,    21,    43,    44,    35,    45,    45,    13,
-      29,    30,    43,    48,    31,    32,    36,    53,    32,    21,
-      26,    48,    28,    36,    21,    44,    53,    48,    47,    26,
+      30,    31,    43,    48,    22,    32,    36,    53,    22,    21,
+      27,    48,    29,    36,    21,    44,    53,    47,    48,    27,
       21,    38,    41,    45,    47,    45,     6,    53,    45
 };
 
@@ -1446,199 +1446,199 @@ yyreduce:
   switch (yyn)
     {
   case 2: /* rc: %empty  */
-#line 37 "sys/cmd/rc/syntax.y"
+#line 38 "sys/cmd/rc/syntax.y"
             { return 0; }
 #line 1452 "sys/cmd/rc/parse.c"
     break;
 
   case 3: /* rc: line '\n'  */
-#line 38 "sys/cmd/rc/syntax.y"
+#line 39 "sys/cmd/rc/syntax.y"
             { return compile((yyvsp[-1].tree)); }
 #line 1458 "sys/cmd/rc/parse.c"
     break;
 
   case 5: /* line: cmds line  */
-#line 42 "sys/cmd/rc/syntax.y"
+#line 43 "sys/cmd/rc/syntax.y"
             { (yyval.tree) = maketree2(';', (yyvsp[-1].tree), (yyvsp[0].tree)); }
 #line 1464 "sys/cmd/rc/parse.c"
     break;
 
   case 7: /* body: cmdsln body  */
-#line 46 "sys/cmd/rc/syntax.y"
+#line 47 "sys/cmd/rc/syntax.y"
               { (yyval.tree) = maketree2(';', (yyvsp[-1].tree), (yyvsp[0].tree)); }
 #line 1470 "sys/cmd/rc/parse.c"
     break;
 
   case 8: /* paren: '(' body ')'  */
-#line 49 "sys/cmd/rc/syntax.y"
+#line 50 "sys/cmd/rc/syntax.y"
                { (yyval.tree) = maketree1(Tparen, (yyvsp[-1].tree)); }
 #line 1476 "sys/cmd/rc/parse.c"
     break;
 
   case 9: /* block: '{' body '}'  */
-#line 52 "sys/cmd/rc/syntax.y"
+#line 53 "sys/cmd/rc/syntax.y"
                { (yyval.tree) = maketree1(Tblock, (yyvsp[-1].tree)); }
 #line 1482 "sys/cmd/rc/parse.c"
     break;
 
   case 11: /* cmds: cmd '&'  */
-#line 56 "sys/cmd/rc/syntax.y"
+#line 57 "sys/cmd/rc/syntax.y"
           { (yyval.tree) = maketree1('&', (yyvsp[-1].tree)); }
 #line 1488 "sys/cmd/rc/parse.c"
     break;
 
   case 14: /* ifbody: cmd  */
-#line 63 "sys/cmd/rc/syntax.y"
+#line 64 "sys/cmd/rc/syntax.y"
                      { (yyval.tree) = maketree2(Tif, nil, (yyvsp[0].tree)); }
 #line 1494 "sys/cmd/rc/parse.c"
     break;
 
   case 15: /* ifbody: block Telse nl cmd  */
-#line 64 "sys/cmd/rc/syntax.y"
+#line 65 "sys/cmd/rc/syntax.y"
                      { (yyval.tree) = maketree3(Tif, nil, (yyvsp[-3].tree), (yyvsp[-2].tree)); }
 #line 1500 "sys/cmd/rc/parse.c"
     break;
 
   case 16: /* assign: executable '=' word  */
-#line 67 "sys/cmd/rc/syntax.y"
+#line 68 "sys/cmd/rc/syntax.y"
                         { (yyval.tree) = maketree2('=', (yyvsp[-2].tree), (yyvsp[0].tree)); }
 #line 1506 "sys/cmd/rc/parse.c"
     break;
 
   case 18: /* redir: Tredir word  */
-#line 71 "sys/cmd/rc/syntax.y"
+#line 72 "sys/cmd/rc/syntax.y"
                            { (yyval.tree) = hangchild1((yyvsp[-1].tree), (yyvsp[0].tree), 0); }
 #line 1512 "sys/cmd/rc/parse.c"
     break;
 
   case 19: /* epilog: %empty  */
-#line 74 "sys/cmd/rc/syntax.y"
+#line 75 "sys/cmd/rc/syntax.y"
                 { (yyval.tree) = nil; }
 #line 1518 "sys/cmd/rc/parse.c"
     break;
 
   case 20: /* epilog: redir epilog  */
-#line 75 "sys/cmd/rc/syntax.y"
+#line 76 "sys/cmd/rc/syntax.y"
                 { (yyval.tree) = hangchild1((yyvsp[-1].tree), (yyvsp[0].tree), 1); }
 #line 1524 "sys/cmd/rc/parse.c"
     break;
 
   case 21: /* cmd: %empty  */
-#line 78 "sys/cmd/rc/syntax.y"
+#line 79 "sys/cmd/rc/syntax.y"
                           { (yyval.tree) = nil; }
 #line 1530 "sys/cmd/rc/parse.c"
     break;
 
   case 22: /* cmd: basic  */
-#line 79 "sys/cmd/rc/syntax.y"
+#line 80 "sys/cmd/rc/syntax.y"
                           { (yyval.tree) = maketree1(Tbasic, (yyvsp[0].tree)); }
 #line 1536 "sys/cmd/rc/parse.c"
     break;
 
   case 23: /* cmd: block epilog  */
-#line 80 "sys/cmd/rc/syntax.y"
+#line 81 "sys/cmd/rc/syntax.y"
                           { (yyval.tree) = hangepilog((yyvsp[-1].tree), (yyvsp[0].tree)); }
 #line 1542 "sys/cmd/rc/parse.c"
     break;
 
   case 24: /* cmd: cmd Tpipe nl cmd  */
-#line 81 "sys/cmd/rc/syntax.y"
+#line 82 "sys/cmd/rc/syntax.y"
                           { (yyval.tree) = hangchild2((yyvsp[-2].tree), (yyvsp[-3].tree), 0, (yyvsp[0].tree), 1); }
 #line 1548 "sys/cmd/rc/parse.c"
     break;
 
   case 25: /* cmd: redir cmd  */
-#line 82 "sys/cmd/rc/syntax.y"
+#line 83 "sys/cmd/rc/syntax.y"
                           { (yyval.tree) = hangchild1((yyvsp[-1].tree), (yyvsp[0].tree), 1); }
 #line 1554 "sys/cmd/rc/parse.c"
     break;
 
   case 26: /* cmd: assign cmd  */
-#line 83 "sys/cmd/rc/syntax.y"
+#line 84 "sys/cmd/rc/syntax.y"
                           { (yyval.tree) = hangchild1((yyvsp[-1].tree), (yyvsp[0].tree), 2); }
 #line 1560 "sys/cmd/rc/parse.c"
     break;
 
   case 27: /* cmd: Tif paren nl ifbody  */
-#line 84 "sys/cmd/rc/syntax.y"
+#line 85 "sys/cmd/rc/syntax.y"
                           { (yyval.tree) = hangchild1((yyvsp[-2].tree), (yyvsp[-3].tree), 0); }
 #line 1566 "sys/cmd/rc/parse.c"
     break;
 
   case 28: /* cmd: Tbang cmd  */
-#line 85 "sys/cmd/rc/syntax.y"
+#line 86 "sys/cmd/rc/syntax.y"
                           { (yyval.tree) = maketree1(Tbang, (yyvsp[0].tree)); }
 #line 1572 "sys/cmd/rc/parse.c"
     break;
 
   case 29: /* cmd: Tsubshell cmd  */
-#line 86 "sys/cmd/rc/syntax.y"
+#line 87 "sys/cmd/rc/syntax.y"
                           { (yyval.tree) = maketree1(Tsubshell, (yyvsp[0].tree)); }
 #line 1578 "sys/cmd/rc/parse.c"
     break;
 
   case 31: /* basic: basic word  */
-#line 90 "sys/cmd/rc/syntax.y"
+#line 91 "sys/cmd/rc/syntax.y"
                 { (yyval.tree) = maketree2(Targs, (yyvsp[-1].tree), (yyvsp[0].tree)); }
 #line 1584 "sys/cmd/rc/parse.c"
     break;
 
   case 32: /* basic: basic redir  */
-#line 91 "sys/cmd/rc/syntax.y"
+#line 92 "sys/cmd/rc/syntax.y"
                 { (yyval.tree) = maketree2(Targs, (yyvsp[-1].tree), (yyvsp[0].tree)); }
 #line 1590 "sys/cmd/rc/parse.c"
     break;
 
   case 34: /* atom: keyword  */
-#line 95 "sys/cmd/rc/syntax.y"
+#line 96 "sys/cmd/rc/syntax.y"
                       { (yyval.tree) = maketree1(Tword, (yyvsp[0].tree)); }
 #line 1596 "sys/cmd/rc/parse.c"
     break;
 
   case 36: /* word: word '^' atom  */
-#line 99 "sys/cmd/rc/syntax.y"
+#line 100 "sys/cmd/rc/syntax.y"
                       { (yyval.tree) = maketree2('^', (yyvsp[-2].tree), (yyvsp[0].tree)); }
 #line 1602 "sys/cmd/rc/parse.c"
     break;
 
   case 38: /* executable: executable '^' atom  */
-#line 103 "sys/cmd/rc/syntax.y"
+#line 104 "sys/cmd/rc/syntax.y"
                       { (yyval.tree) = maketree2('^', (yyvsp[-2].tree), (yyvsp[0].tree)); }
 #line 1608 "sys/cmd/rc/parse.c"
     break;
 
   case 40: /* nonkeyword: '$' atom  */
-#line 107 "sys/cmd/rc/syntax.y"
+#line 108 "sys/cmd/rc/syntax.y"
                   { (yyval.tree) = maketree1('$', (yyvsp[0].tree)); }
 #line 1614 "sys/cmd/rc/parse.c"
     break;
 
   case 41: /* nonkeyword: '(' wordsnl ')'  */
-#line 108 "sys/cmd/rc/syntax.y"
+#line 109 "sys/cmd/rc/syntax.y"
                   { (yyval.tree) = (yyvsp[-1].tree); }
 #line 1620 "sys/cmd/rc/parse.c"
     break;
 
   case 42: /* nonkeyword: Tcount atom  */
-#line 109 "sys/cmd/rc/syntax.y"
+#line 110 "sys/cmd/rc/syntax.y"
                   { (yyval.tree) = maketree1(Tcount, (yyvsp[0].tree)); }
 #line 1626 "sys/cmd/rc/parse.c"
     break;
 
   case 43: /* nonkeyword: Tflat atom  */
-#line 110 "sys/cmd/rc/syntax.y"
+#line 111 "sys/cmd/rc/syntax.y"
                   { (yyval.tree) = maketree1(Tflat, (yyvsp[0].tree)); }
 #line 1632 "sys/cmd/rc/parse.c"
     break;
 
   case 48: /* wordsnl: %empty  */
-#line 121 "sys/cmd/rc/syntax.y"
+#line 122 "sys/cmd/rc/syntax.y"
                { (yyval.tree) = nil; }
 #line 1638 "sys/cmd/rc/parse.c"
     break;
 
   case 50: /* wordsnl: wordsnl word  */
-#line 123 "sys/cmd/rc/syntax.y"
+#line 124 "sys/cmd/rc/syntax.y"
                {(yyval.tree) = (!(yyvsp[-1].tree)) ? ((!(yyvsp[0].tree)) ? nil : (yyvsp[0].tree)) : ((!(yyvsp[0].tree)) ? (yyvsp[-1].tree) : maketree2(Twords, (yyvsp[-1].tree), (yyvsp[0].tree))); }
 #line 1644 "sys/cmd/rc/parse.c"
     break;
@@ -1868,5 +1868,5 @@ yyreturnlab:
   return yyresult;
 }
 
-#line 128 "sys/cmd/rc/syntax.y"
+#line 129 "sys/cmd/rc/syntax.y"
 
diff --git a/sys/cmd/rc/parse.h b/sys/cmd/rc/parse.h
index c30606d..ef389bc 100644
--- a/sys/cmd/rc/parse.h
+++ b/sys/cmd/rc/parse.h
@@ -107,7 +107,7 @@ extern int yydebug;
 #if ! defined YYSTYPE && ! defined YYSTYPE_IS_DECLARED
 union YYSTYPE
 {
-#line 23 "sys/cmd/rc/syntax.y"
+#line 24 "sys/cmd/rc/syntax.y"
 
     struct Tree *tree;
 
diff --git a/sys/cmd/rc/syntax.y b/sys/cmd/rc/syntax.y
index cb4a174..76bcd88 100644
--- a/sys/cmd/rc/syntax.y
+++ b/sys/cmd/rc/syntax.y
@@ -16,6 +16,7 @@
 %left '\n'
 %left Tbang Tsubshell
 %left Tpipe;
+%left '^';
 %right '$' Tcount Tflat
 %left Tindex