--stderr does not direct all stderr writes to file

[u20221022]

I did this

curl.exe -I --stderr err.txt --write-out "%{stderr}%{json}" "https://curl.se/" > Nul
{"content_type":"text/html","errormsg":null,"exitcode":0,"filename_effective":null,"ftp_entry_path":null,"http_code":200,"http_connect":0,"http_version":"2","local_ip":"?.?.?.?","local_port":?,"method":"HEAD","num_connects":1,"num_headers":21,"num_redirects":0,"proxy_ssl_verify_result":0,"redirect_url":null,"referer":null,"remote_ip":"151.101.65.91","remote_port":443,"response_code":200,"scheme":"HTTPS","size_download":0,"size_header":845,"size_request":70,"size_upload":0,"speed_download":0,"speed_upload":0,"ssl_verify_result":0,"time_appconnect":1.604500,"time_connect":0.221004,"time_namelookup":0.019257,"time_pretransfer":1.384094,"time_redirect":0.000000,"time_starttransfer":1.469586,"time_total":1.470412,"url":"https://curl.se/","url_effective":"https://curl.se/","urlnum":0,"curl_version":"libcurl/7.87.0 OpenSSL/3.0.8 (Schannel) zlib/1.2.13 brotli/1.0.9 zstd/1.5.4 WinIDN libssh2/1.10.0 nghttp2/1.51.0 ngtcp2/0.13.1 nghttp3/0.8.0 libgsasl/2.2.0"}
dir err.txt
Том в устройстве ? имеет метку ?
Серийный номер тома: ?

Содержимое папки ?:?\curl-7.87.0_7-win64-mingw\bin

13.02.2023 05:00 0 err.txt
1 файлов 0 байт
0 папок ? байт свободно
curl.exe -I --stderr err.txt --write-out "%{stderr}%{json}" "htps://curl.se/" > Nul
{"content_type":null,"errormsg":"Protocol "htps" not supported or disabled in libcurl","exitcode":1,"filename_effective":null,"ftp_entry_path":null,"http_code":0,"http_connect":0,"http_version":"0","local_ip":"","local_port":0,"method":"HEAD","num_connects":0,"num_headers":0,"num_redirects":0,"proxy_ssl_verify_result":0,"redirect_url":null,"referer":null,"remote_ip":"","remote_port":0,"response_code":0,"scheme":null,"size_download":0,"size_header":0,"size_request":0,"size_upload":0,"speed_download":0,"speed_upload":0,"ssl_verify_result":0,"time_appconnect":0.000000,"time_connect":0.000000,"time_namelookup":0.000000,"time_pretransfer":0.000000,"time_redirect":0.000000,"time_starttransfer":0.000000,"time_total":0.000000,"url":"htps://curl.se/","url_effective":"htps://curl.se/","urlnum":0,"curl_version":"libcurl/7.87.0 OpenSSL/3.0.8 (Schannel) zlib/1.2.13 brotli/1.0.9 zstd/1.5.4 WinIDN libssh2/1.10.0 nghttp2/1.51.0 ngtcp2/0.13.1 nghttp3/0.8.0 libgsasl/2.2.0"}
type err.txt
curl: (1) Protocol "htps" not supported or disabled in libcurl

I expected the following

Какой-нибудь глюк типа «not-a-bug» (#10459 и другие). Иначе не стал бы время тратить на такую примитивную проверку.
«Верной дорогой идёте, товарищи!»©

curl/libcurl version

7.87.0
[curl -V output]
curl 7.87.0 (x86_64-w64-mingw32) libcurl/7.87.0 OpenSSL/3.0.8 (Schannel) zlib/1.2.13 brotli/1.0.9 zstd/1.5.4 WinIDN libssh2/1.10.0 nghttp2/1.51.0 ngtcp2/0.13.1 nghttp3/0.8.0 libgsasl/2.2.0
Release-Date: 2022-12-21
Protocols: dict file ftp ftps gopher gophers http https imap imaps ldap ldaps mqtt pop3 pop3s rtsp scp sftp smb smbs smtp smtps telnet tftp ws wss
Features: alt-svc AsynchDNS brotli gsasl HSTS HTTP2 HTTP3 HTTPS-proxy IDN IPv6 Kerberos Largefile libz MultiSSL NTLM SPNEGO SSL SSPI threadsafe TLS-SRP UnixSockets zstd

operating system

MS Windows

[u20221022]

Я не понимаю, что происходит, поэтому не могу быть уверен в том, что подобрал подходящий заголовок; извините.

---

I don't understand what's going on, so I can't be sure I've picked the right title; Sorry.

[jay]

Please tell us in English. It looks like you are reporting that --write-out %{stderr} does not direct its output to the --stderr file. That is true, it goes directly to stderr. I'm not sure if that was intended or not. The --stderr documentation does say "Redirect all writes to stderr to the specified file instead." hm.

curl/src/tool_writeout.c

Lines 425 to 427 in 7ce140b

	case VAR_STDERR:
	stream = stderr;
	break;

The code could be changed to use the stream opened by --stderr (see below) but I wonder if we are just covering up a larger problem here, like maybe it would be better to freopen stderr when --stderr?

diff --git a/src/tool_operate.c b/src/tool_operate.c
index c9583b8..ca361bd 100644
--- a/src/tool_operate.c
+++ b/src/tool_operate.c
@@ -660,7 +660,7 @@ static CURLcode post_per_transfer(struct GlobalConfig *global,
 
   /* Write the --write-out data before cleanup but after result is final */
   if(config->writeout)
-    ourWriteOut(config->writeout, per, result);
+    ourWriteOut(config, per, result);
 
   /* Close function-local opened file descriptors */
   if(per->heads.fopened && per->heads.stream)
diff --git a/src/tool_writeout.c b/src/tool_writeout.c
index 5246db2..d93de82 100644
--- a/src/tool_writeout.c
+++ b/src/tool_writeout.c
@@ -376,15 +376,19 @@ static int writeOffset(FILE *stream, const struct writeoutvar *wovar,
   return 1; /* return 1 if anything was written */
 }
 
-void ourWriteOut(const char *writeinfo, struct per_transfer *per,
+void ourWriteOut(struct OperationConfig *config, struct per_transfer *per,
                  CURLcode per_result)
 {
   FILE *stream = stdout;
+  const char *writeinfo = config->writeout;
   const char *ptr = writeinfo;
   bool done = FALSE;
   struct curl_certinfo *certinfo;
   CURLcode res = curl_easy_getinfo(per->curl, CURLINFO_CERTINFO, &certinfo);
 
+  if(!writeinfo)
+    return;
+
   if(!res && certinfo)
     per->certinfo = certinfo;
 
@@ -423,7 +427,7 @@ void ourWriteOut(const char *writeinfo, struct per_transfer *per,
                 stream = stdout;
                 break;
               case VAR_STDERR:
-                stream = stderr;
+                stream = config->global->errors;
                 break;
               case VAR_JSON:
                 ourWriteOutJSON(stream, variables, per, per_result);
diff --git a/src/tool_writeout.h b/src/tool_writeout.h
index 0c07f22..fac7bdd 100644
--- a/src/tool_writeout.h
+++ b/src/tool_writeout.h
@@ -84,7 +84,7 @@ struct writeoutvar {
                    bool use_json);
 };
 
-void ourWriteOut(const char *writeinfo, struct per_transfer *per,
+void ourWriteOut(struct OperationConfig *config, struct per_transfer *per,
                  CURLcode per_result);
 
 #endif /* HEADER_CURL_TOOL_WRITEOUT_H */

[bagder]

I'm not sure if that was intended or not

I don't think it was intended but an oversight. I think you can do a proper PR with your change.

We never defined exactly what --stderr should redirect, but I consider it an alternative for systems that cannot redirect stderr with 2>file so basically everything stderr should go there.