apps/hello: Demo fgets

apps/hello.c

@@ -3,4 +3,10 @@
 int main(int argc, char** argv)
 {
     printf("Hello world! argc=%d, argv[0]=%s, argv[1]=%s, argv[2]=%s\n", argc, argv[0], argv[1], argv[2]);
+
+    char buf[1024];
+    char* rc = fgets(buf, sizeof(buf), stdin);
+    if (!rc) perror("fgets");
+
+    fputs(buf, stdout);
 }