ash: implement <<<here_string syntax

function                                             old     new   delta
write2pipe                                             -     133    +133
.rodata                                           105992  106009     +17
readtoken1                                          3101    3111     +10
cmdtxt                                               631     641     +10
nodesize                                              27      28      +1
redirect                                             961     916     -45
------------------------------------------------------------------------------
(add/remove: 1/0 grow/shrink: 4/1 up/down: 171/-45)           Total: 126 bytes

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

3 files changed, 129 insertions, 26 deletions

diff --git a/shell/ash.c b/shell/ash.c
index 7a4f7c6a8..b845ac393 100644
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -950,14 +950,15 @@ static const char dolatstr[] ALIGN1 = {
 #endif
 #define NCLOBBER 18
 #define NFROM    19
-#define NFROMTO  20
-#define NAPPEND  21
-#define NTOFD    22
-#define NFROMFD  23
-#define NHERE    24
-#define NXHERE   25
-#define NNOT     26
-#define N_NUMBER 27
+#define NFROMSTR 20
+#define NFROMTO  21
+#define NAPPEND  22
+#define NTOFD    23
+#define NFROMFD  24
+#define NHERE    25
+#define NXHERE   26
+#define NNOT     27
+#define N_NUMBER 28
 
 union node;
 
@@ -1388,6 +1389,7 @@ shcmd(union node *cmd, FILE *fp)
 #endif
                 case NTOFD:    s = ">&"; dftfd = 1; break;
                 case NFROM:    s = "<"; break;
+                case NFROMSTR: s = "<<<"; break;
                 case NFROMFD:  s = "<&"; break;
                 case NFROMTO:  s = "<>"; break;
                 default:       s = "*error*"; break;
@@ -5180,6 +5182,9 @@ cmdtxt(union node *n)
         case NXHERE:
                 p = "<<...";
                 goto dotail2;
+        case NFROMSTR:
+                p = "<<<";
+                goto dotail2;
         case NCASE:
                 cmdputs("case ");
                 cmdputs(n->ncase.expr->narg.text);
@@ -5633,25 +5638,9 @@ stoppedjobs(void)
  * data to a pipe.  If the document is short, we can stuff the data in
  * the pipe without forking.
  */
-/* openhere needs this forward reference */
-static void expandhere(union node *arg);
 static int
-openhere(union node *redir)
+write2pipe(int pip[2], const char *p, size_t len)
 {
-        char *p;
-        int pip[2];
-        size_t len = 0;
-
-        if (pipe(pip) < 0)
-                ash_msg_and_raise_perror("can't create pipe");
-
-        p = redir->nhere.doc->narg.text;
-        if (redir->type == NXHERE) {
-                expandhere(redir->nhere.doc);
-                p = stackblock();
-        }
-
-        len = strlen(p);
         if (len <= PIPE_BUF) {
                 xwrite(pip[1], p, len);
                 goto out;
@@ -5673,6 +5662,42 @@ openhere(union node *redir)
         return pip[0];
 }
 
+/* openhere needs this forward reference */
+static void expandhere(union node *arg);
+static int
+openhere(union node *redir)
+{
+        char *p;
+        int pip[2];
+
+        if (pipe(pip) < 0)
+                ash_msg_and_raise_perror("can't create pipe");
+
+        p = redir->nhere.doc->narg.text;
+        if (redir->type == NXHERE) {
+                expandhere(redir->nhere.doc);
+                p = stackblock();
+        }
+
+        return write2pipe(pip, p, strlen(p));
+}
+
+static int
+openherestr(char *str)
+{
+        int pip[2];
+        size_t len;
+
+        if (pipe(pip) < 0)
+                ash_msg_and_raise_perror("can't create pipe");
+
+        len = strlen(str);
+        str[len] = '\n';
+        write2pipe(pip, str, len + 1);
+        str[len] = '\0';
+        return pip[0];
+}
+
 static int
 openredirect(union node *redir)
 {
@@ -5687,6 +5712,9 @@ openredirect(union node *redir)
  do_open:
                 f = sh_open(redir->nfile.expfname, flags, 0);
                 break;
+        case NFROMSTR:
+                f = openherestr(redir->nfile.expfname);
+                break;
         case NFROMTO:
                 flags = O_RDWR|O_CREAT;
                 goto do_open;
@@ -9188,6 +9216,7 @@ calcsize(int funcblocksize, union node *n)
 #endif
         case NCLOBBER:
         case NFROM:
+        case NFROMSTR:
         case NFROMTO:
         case NAPPEND:
                 funcblocksize = calcsize(funcblocksize, n->nfile.fname);
@@ -9310,6 +9339,7 @@ copynode(union node *n)
 #endif
         case NCLOBBER:
         case NFROM:
+        case NFROMSTR:
         case NFROMTO:
         case NAPPEND:
                 new->nfile.fname = copynode(n->nfile.fname);
@@ -9778,6 +9808,7 @@ expredir(union node *n)
                 switch (redir->type) {
                 case NFROMTO:
                 case NFROM:
+                case NFROMSTR:
                 case NTO:
 #if BASH_REDIR_OUTPUT
                 case NTO2:
@@ -12970,6 +13001,11 @@ parseredir: {
                 c = pgetc_eatbnl();
                 switch (c) {
                 case '<':
+                        c = pgetc_eatbnl();
+                        if (c == '<') {
+                                np->type = NFROMSTR;
+                                break;
+                        }
                         if (sizeof(struct nfile) != sizeof(struct nhere)) {
                                 np = stzalloc(sizeof(struct nhere));
                                 /*np->nfile.fd = 0; - stzalloc did it */
@@ -12977,7 +13013,6 @@ parseredir: {
                         np->type = NHERE;
                         heredoc = stzalloc(sizeof(struct heredoc));
                         heredoc->here = np;
-                        c = pgetc_eatbnl();
                         if (c == '-') {
                                 heredoc->striptabs = 1;
                         } else {
diff --git a/shell/ash_test/ash-heredoc/herestring1.right b/shell/ash_test/ash-heredoc/herestring1.right
new file mode 100644
index 000000000..555937daa
--- /dev/null
+++ b/shell/ash_test/ash-heredoc/herestring1.right
@@ -0,0 +1,33 @@
+one
+_two
+\_three
+\_four
+\_two
+\_three
+\\_four
+two_newlines
+
+/bin/c*
+star_*
+star_*
+star_*
+star_\*
+star_*
+star_\*
+line1
+line2
+        line3
+line1
+line2
+        line3
+512
+256
+128
+64
+32
+16
+8
+4
+2
+v-$a-\t-\-\"-\x-`-\--\z-\*-\?-
+v-$a-\t-\-"-\x-`-\--\z-\*-\?-
diff --git a/shell/ash_test/ash-heredoc/herestring1.tests b/shell/ash_test/ash-heredoc/herestring1.tests
new file mode 100755
index 000000000..fb7bd0dda
--- /dev/null
+++ b/shell/ash_test/ash-heredoc/herestring1.tests
@@ -0,0 +1,35 @@
+cat <<<one
+cat <<<\_two
+cat <<<"\_three"
+cat <<<'\_four'
+cat <<<\\_two
+cat <<<"\\_three"
+cat <<<'\\_four'
+
+cat <<<$'two_newlines\n'
+
+cat <<</bin/c*
+
+cat <<<star_*
+cat <<<star_\*
+cat <<<"star_*"
+cat <<<"star_\*"
+cat <<<'star_*'
+cat <<<'star_\*'
+
+var=$'line1
+line2
+        line3'
+
+cat <<<$var
+
+cat <<<"$var"
+
+i=10
+until test $((--i)) = 0; do
+        cat <<<$((2**i))
+done
+
+a=qwerty
+cat <<<`echo v'-$a-\t-\\-\"-\x-\`-\--\z-\*-\?-'`
+cat <<<"`echo v'-$a-\t-\\-\"-\x-\`-\--\z-\*-\?-'`"