feat(rc): string join operator

1 files changed, 41 insertions, 0 deletions

diff --git a/sys/cmd/rc/exec.c b/sys/cmd/rc/exec.c
index ac0dc08..425d00f 100644
--- a/sys/cmd/rc/exec.c
+++ b/sys/cmd/rc/exec.c
@@ -625,6 +625,47 @@ Xconcatenate(void)
 }
 
 void
+Xjoin(void)
+{
+    int  n;
+    char *s;
+    Word *arg, *elt;
+
+    if(count(runner->args->word) != 1){
+        Xerror("variable name is not singleton\n");
+        return;
+    }
+
+    s = runner->args->word->str;
+    // deglob(s)
+
+    arg = var(s)->val;
+    poplist();
+
+    n = count(arg);
+    if(n==0){
+        pushword("");
+        return;
+    }
+
+    for(elt = arg; elt; elt=elt->link)
+        n += strlen(elt->str);
+
+    s = emalloc(n);
+    if(arg){
+        strcpy(s, arg->str);
+        for(elt = arg->link; elt; elt = elt->link){
+            strcat(s, " ");
+            strcat(s, elt->str);
+        }
+    }else
+        s[0] = 0;
+
+    pushword(s);
+    efree(s);
+}
+
+void
 Xdollar(void)
 {
     int n;