"nginx -v" outputs is in stderr.

[Takahiro Kujirai]

Hi all,

This is Takahiro Kujirai.

When I typed "nginx -v > /tmp/nginx.txt"  on nginx 1.9.11, I found output
is in stderr.
-------

[root at localhost ~]# nginx -v > /tmp/nginx.txt
nginx version: nginx/1.9.11
[root at localhost ~]#
[root at localhost ~]# nginx -v 2> /tmp/nginx.txt
[root at localhost ~]# cat /tmp/nginx.txt
nginx version: nginx/1.9.11


I read source code(line374-434 of
https://github.com/nginx/nginx/blob/master/src/core/nginx.c),
I found using ngx_write_stderr.
-------
static void
ngx_show_version_info()
{
    ngx_write_stderr("nginx version: " NGINX_VER_BUILD NGX_LINEFEED);

    if (ngx_show_help) {
        ngx_write_stderr(
            "Usage: nginx [-?hvVtTq] [-s signal] [-c filename] "
                         "[-p prefix] [-g directives]" NGX_LINEFEED
                         NGX_LINEFEED
            "Options:" NGX_LINEFEED
            "  -?,-h         : this help" NGX_LINEFEED
            "  -v            : show version and exit" NGX_LINEFEED
            "  -V            : show version and configure options then
exit"
                               NGX_LINEFEED
            "  -t            : test configuration and exit" NGX_LINEFEED
            "  -T            : test configuration, dump it and exit"
                               NGX_LINEFEED
            "  -q            : suppress non-error messages "
                               "during configuration testing" NGX_LINEFEED
            "  -s signal     : send signal to a master process: "
                               "stop, quit, reopen, reload" NGX_LINEFEED
#ifdef NGX_PREFIX
            "  -p prefix     : set prefix path (default: " NGX_PREFIX ")"
                               NGX_LINEFEED
#else
            "  -p prefix     : set prefix path (default: NONE)"
NGX_LINEFEED
#endif
            "  -c filename   : set configuration file (default: "
NGX_CONF_PATH
                               ")" NGX_LINEFEED
            "  -g directives : set global directives out of configuration "
                               "file" NGX_LINEFEED NGX_LINEFEED
        );
    }

    if (ngx_show_configure) {

#ifdef NGX_COMPILER
        ngx_write_stderr("built by " NGX_COMPILER NGX_LINEFEED);
#endif

#if (NGX_SSL)
        if (SSLeay() == SSLEAY_VERSION_NUMBER) {
            ngx_write_stderr("built with " OPENSSL_VERSION_TEXT
NGX_LINEFEED);
        } else {
            ngx_write_stderr("built with " OPENSSL_VERSION_TEXT
                             " (running with ");
            ngx_write_stderr((char *) (uintptr_t)
                             SSLeay_version(SSLEAY_VERSION));
            ngx_write_stderr(")" NGX_LINEFEED);
        }
#ifdef SSL_CTRL_SET_TLSEXT_HOSTNAME
        ngx_write_stderr("TLS SNI support enabled" NGX_LINEFEED);
#else
        ngx_write_stderr("TLS SNI support disabled" NGX_LINEFEED);
#endif
#endif

        ngx_write_stderr("configure arguments:" NGX_CONFIGURE
NGX_LINEFEED);
    }
}




I think "stdout" is good, not "stderr", is this the design?


And I created patch for this problem.
-------
[root at localhost ~]# diff -u ./src/core/nginx.c ./src2/core/nginx.c
--- ./src/core/nginx.c2016-02-10 22:56:57.915997223 +0900
+++ ./src2/core/nginx.c2016-02-09 23:11:57.000000000 +0900
@@ -374,10 +374,10 @@
 static void
 ngx_show_version_info()
 {
-    ngx_write_stdout("nginx version: " NGINX_VER_BUILD NGX_LINEFEED);
+    ngx_write_stderr("nginx version: " NGINX_VER_BUILD NGX_LINEFEED);

     if (ngx_show_help) {
-        ngx_write_stdout(
+        ngx_write_stderr(
             "Usage: nginx [-?hvVtTq] [-s signal] [-c filename] "
                          "[-p prefix] [-g directives]" NGX_LINEFEED
                          NGX_LINEFEED
@@ -409,27 +409,27 @@
     if (ngx_show_configure) {

 #ifdef NGX_COMPILER
-        ngx_write_stdout("built by " NGX_COMPILER NGX_LINEFEED);
+        ngx_write_stderr("built by " NGX_COMPILER NGX_LINEFEED);
 #endif

 #if (NGX_SSL)
         if (SSLeay() == SSLEAY_VERSION_NUMBER) {
-            ngx_write_stdout("built with " OPENSSL_VERSION_TEXT
NGX_LINEFEED);
+            ngx_write_stderr("built with " OPENSSL_VERSION_TEXT
NGX_LINEFEED);
         } else {
-            ngx_write_stdout("built with " OPENSSL_VERSION_TEXT
+            ngx_write_stderr("built with " OPENSSL_VERSION_TEXT
                              " (running with ");
-            ngx_write_stdout((char *) (uintptr_t)
+            ngx_write_stderr((char *) (uintptr_t)
                              SSLeay_version(SSLEAY_VERSION));
-            ngx_write_stdout(")" NGX_LINEFEED);
+            ngx_write_stderr(")" NGX_LINEFEED);
         }
 #ifdef SSL_CTRL_SET_TLSEXT_HOSTNAME
-        ngx_write_stdout("TLS SNI support enabled" NGX_LINEFEED);
+        ngx_write_stderr("TLS SNI support enabled" NGX_LINEFEED);
 #else
-        ngx_write_stdout("TLS SNI support disabled" NGX_LINEFEED);
+        ngx_write_stderr("TLS SNI support disabled" NGX_LINEFEED);
 #endif
 #endif

-        ngx_write_stdout("configure arguments:" NGX_CONFIGURE
NGX_LINEFEED);
+        ngx_write_stderr("configure arguments:" NGX_CONFIGURE
NGX_LINEFEED);
     }
 }


Best Regards,
Takahiro Kujirai
@Zeus-Enterprise.Co.Ltd