From 5ab527e66920681f9fcd44449d96bfd08f96fa31 Mon Sep 17 00:00:00 2001
From: Kefu Chai <kefu.chai@scylladb.com>
Date: Fri, 19 Apr 2024 14:28:23 +0800
Subject: [PATCH] main: do not echo parsed options when calling scylla
 interactively

in 2f0f53ac, we added logging of parsed command line options so that we
can see how scylla is launched in case it fails to boot. but when scylla
is called interactively in console. this echo is a little bit annoying.
see following console session
```console
$ scylla --help-loggers
Scylla version 5.5.0~dev-0.20240419.3c9651adf297 with build-id 7dd6a110e608535e5c259a03548eda6517ab4bde starting ...
command used: "./RelWithDebInfo/scylla --help-loggers"
pid: 996503
parsed command line options: [help-loggers]
Available loggers:
    BatchStatement
    LeveledManifest
    alter_keyspace
    alter_table
...
```

so in this change, we check if the stdin is associated with a terminal
device, if that the case, we don't print the scylla version, parsed
command line and pid. and the interactive session looks like:

```console
$ scylla --help-loggers
Available loggers:
    BatchStatement
    LeveledManifest
    alter_keyspace
    alter_table
```
no more distracting information printed. the original behavior
can be tested like:

```console
$ : | ./RelWithDebInfo/scylla --help-loggers
```

assuming scylla is always launched with systemd, which connects
stdin to /dev/null. see
https://www.freedesktop.org/software/systemd/man/latest/systemd.exec.html#Logging%20and%20Standard%20Input/Output
. so this behavior is preserved with this change.

Refs #4203

Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>

Closes scylladb/scylladb#18309
---
 main.cc | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/main.cc b/main.cc
index 6be7fe77ec..ce5eb5f149 100644
--- a/main.cc
+++ b/main.cc
@@ -59,6 +59,7 @@
 #include "repair/row_level.hh"
 #include <cstdio>
 #include <seastar/core/file.hh>
+#include <unistd.h>
 #include <sys/time.h>
 #include <sys/resource.h>
 #include <sys/prctl.h>
@@ -638,8 +639,10 @@ To start the scylla server proper, simply invoke as: scylla server (or just scyl
 
     // If --version is requested, print it out and exit immediately to avoid
     // Seastar-specific warnings that may occur when running the app
-    auto parsed_opts = bpo::command_line_parser(ac, av).options(app.get_options_description()).allow_unregistered().run();
-    print_starting_message(ac, av, parsed_opts);
+    if (!isatty(fileno(stdin))) {
+        auto parsed_opts = bpo::command_line_parser(ac, av).options(app.get_options_description()).allow_unregistered().run();
+        print_starting_message(ac, av, parsed_opts);
+    }
 
     sharded<locator::shared_token_metadata> token_metadata;
     sharded<locator::effective_replication_map_factory> erm_factory;