examples: use stderr for messages, stdout for data

Reported by: Karel Srot
Bug: https://bugzilla.redhat.com/867462

example/direct_tcpip.c

@@ -135,7 +135,7 @@ int main(int argc, char *argv[])
 
     /* check what authentication methods are available */
     userauthlist = libssh2_userauth_list(session, username, strlen(username));
-    printf("Authentication methods: %s\n", userauthlist);
+    fprintf(stderr, "Authentication methods: %s\n", userauthlist);
     if (strstr(userauthlist, "password"))
         auth |= AUTH_PASSWORD;
     if (strstr(userauthlist, "publickey"))
@@ -157,12 +157,12 @@ int main(int argc, char *argv[])
     } else if (auth & AUTH_PUBLICKEY) {
         if (libssh2_userauth_publickey_fromfile(session, username, keyfile1,
                                                 keyfile2, password)) {
-            printf("\tAuthentication by public key failed!\n");
+            fprintf(stderr, "\tAuthentication by public key failed!\n");
             goto shutdown;
         }
-        printf("\tAuthentication by public key succeeded.\n");
+        fprintf(stderr, "\tAuthentication by public key succeeded.\n");
     } else {
-        printf("No supported authentication methods found!\n");
+        fprintf(stderr, "No supported authentication methods found!\n");
         goto shutdown;
     }
 
@@ -185,7 +185,7 @@ int main(int argc, char *argv[])
         goto shutdown;
     }
 
-    printf("Waiting for TCP connection on %s:%d...\n",
+    fprintf(stderr, "Waiting for TCP connection on %s:%d...\n",
         inet_ntoa(sin.sin_addr), ntohs(sin.sin_port));
 
     forwardsock = accept(listensock, (struct sockaddr *)&sin, &sinlen);
@@ -197,8 +197,8 @@ int main(int argc, char *argv[])
     shost = inet_ntoa(sin.sin_addr);
     sport = ntohs(sin.sin_port);
 
-    printf("Forwarding connection from %s:%d here to remote %s:%d\n", shost,
+    fprintf(stderr, "Forwarding connection from %s:%d here to remote %s:%d\n",
-        sport, remote_desthost, remote_destport);
+        shost, sport, remote_desthost, remote_destport);
 
     channel = libssh2_channel_direct_tcpip_ex(session, remote_desthost,
         remote_destport, shost, sport);
@@ -228,7 +228,8 @@ int main(int argc, char *argv[])
                 perror("read");
                 goto shutdown;
             } else if (0 == len) {
-                printf("The client at %s:%d disconnected!\n", shost, sport);
+                fprintf(stderr, "The client at %s:%d disconnected!\n", shost,
+                    sport);
                 goto shutdown;
             }
             wr = 0;
@@ -259,7 +260,7 @@ int main(int argc, char *argv[])
                 wr += i;
             }
             if (libssh2_channel_eof(channel)) {
-                printf("The server at %s:%d disconnected!\n",
+                fprintf(stderr, "The server at %s:%d disconnected!\n",
                     remote_desthost, remote_destport);
                 goto shutdown;
             }

example/scp_nonblock.c

@@ -250,7 +250,7 @@ int main(int argc, char *argv[])
     gettimeofday(&end, NULL);
 
     time_ms = tvdiff(end, start);
-    printf("Got %d bytes in %ld ms = %.1f bytes/sec spin: %d\n", total,
+    fprintf(stderr, "Got %d bytes in %ld ms = %.1f bytes/sec spin: %d\n", total,
            time_ms, total/(time_ms/1000.0), spin );
 
     libssh2_channel_free(channel);

example/scp_write_nonblock.c

@@ -243,7 +243,7 @@ int main(int argc, char *argv[])
 
     duration = (int)(time(NULL)-start);
 
-    printf("%ld bytes in %d seconds makes %.1f bytes/sec\n",
+    fprintf(stderr, "%ld bytes in %d seconds makes %.1f bytes/sec\n",
            total, duration, total/(double)duration);
 
     fprintf(stderr, "Sending EOF\n");

example/sftp.c

@@ -55,24 +55,24 @@ static void kbd_callback(const char *name, int name_len,
     char buf[1024];
     (void)abstract;
 
-    printf("Performing keyboard-interactive authentication.\n");
+    fprintf(stderr, "Performing keyboard-interactive authentication.\n");
 
-    printf("Authentication name: '");
+    fprintf(stderr, "Authentication name: '");
-    fwrite(name, 1, name_len, stdout);
+    fwrite(name, 1, name_len, stderr);
-    printf("'\n");
+    fprintf(stderr, "'\n");
 
-    printf("Authentication instruction: '");
+    fprintf(stderr, "Authentication instruction: '");
-    fwrite(instruction, 1, instruction_len, stdout);
+    fwrite(instruction, 1, instruction_len, stderr);
-    printf("'\n");
+    fprintf(stderr, "'\n");
 
-    printf("Number of prompts: %d\n\n", num_prompts);
+    fprintf(stderr, "Number of prompts: %d\n\n", num_prompts);
 
     for (i = 0; i < num_prompts; i++) {
-        printf("Prompt %d from server: '", i);
+        fprintf(stderr, "Prompt %d from server: '", i);
-        fwrite(prompts[i].text, 1, prompts[i].length, stdout);
+        fwrite(prompts[i].text, 1, prompts[i].length, stderr);
-        printf("'\n");
+        fprintf(stderr, "'\n");
 
-        printf("Please type response: ");
+        fprintf(stderr, "Please type response: ");
         fgets(buf, sizeof(buf), stdin);
         n = strlen(buf);
         while (n > 0 && strchr("\r\n", buf[n - 1]))
@@ -82,12 +82,13 @@ static void kbd_callback(const char *name, int name_len,
         responses[i].text = strdup(buf);
         responses[i].length = n;
 
-        printf("Response %d from user is '", i);
+        fprintf(stderr, "Response %d from user is '", i);
-        fwrite(responses[i].text, 1, responses[i].length, stdout);
+        fwrite(responses[i].text, 1, responses[i].length, stderr);
-        printf("'\n\n");
+        fprintf(stderr, "'\n\n");
     }
 
-    printf("Done. Sending keyboard-interactive responses to server now.\n");
+    fprintf(stderr,
+        "Done. Sending keyboard-interactive responses to server now.\n");
 }
 
 
@@ -127,7 +128,7 @@ int main(int argc, char *argv[])
 
     rc = libssh2_init (0);
     if (rc != 0) {
-        fprintf (stderr, "libssh2 initialization failed (%d)\n", rc);
+        fprintf(stderr, "libssh2 initialization failed (%d)\n", rc);
         return 1;
     }
 
@@ -178,7 +179,7 @@ int main(int argc, char *argv[])
 
     /* check what authentication methods are available */
     userauthlist = libssh2_userauth_list(session, username, strlen(username));
-    printf("Authentication methods: %s\n", userauthlist);
+    fprintf(stderr, "Authentication methods: %s\n", userauthlist);
     if (strstr(userauthlist, "password") != NULL) {
         auth_pw |= 1;
     }
@@ -211,21 +212,23 @@ int main(int argc, char *argv[])
     } else if (auth_pw & 2) {
         /* Or via keyboard-interactive */
         if (libssh2_userauth_keyboard_interactive(session, username, &kbd_callback) ) {
-            printf("\tAuthentication by keyboard-interactive failed!\n");
+            fprintf(stderr,
+                "\tAuthentication by keyboard-interactive failed!\n");
             goto shutdown;
         } else {
-            printf("\tAuthentication by keyboard-interactive succeeded.\n");
+            fprintf(stderr,
+                "\tAuthentication by keyboard-interactive succeeded.\n");
         }
     } else if (auth_pw & 4) {
         /* Or by public key */
         if (libssh2_userauth_publickey_fromfile(session, username, keyfile1, keyfile2, password)) {
-            printf("\tAuthentication by public key failed!\n");
+            fprintf(stderr, "\tAuthentication by public key failed!\n");
             goto shutdown;
         } else {
-            printf("\tAuthentication by public key succeeded.\n");
+            fprintf(stderr, "\tAuthentication by public key succeeded.\n");
         }
     } else {
-        printf("No supported authentication methods found!\n");
+        fprintf(stderr, "No supported authentication methods found!\n");
         goto shutdown;
     }
 

example/sftp_RW_nonblock.c

@@ -141,11 +141,11 @@ int main(int argc, char *argv[])
      * user, that's your call
      */
     fingerprint = libssh2_hostkey_hash(session, LIBSSH2_HOSTKEY_HASH_SHA1);
-    printf("Fingerprint: ");
+    fprintf(stderr, "Fingerprint: ");
     for(i = 0; i < 20; i++) {
-        printf("%02X ", (unsigned char)fingerprint[i]);
+        fprintf(stderr, "%02X ", (unsigned char)fingerprint[i]);
     }
-    printf("\n");
+    fprintf(stderr, "\n");
 
     if(argc > 1) {
         username = argv[1];
@@ -162,7 +162,7 @@ int main(int argc, char *argv[])
 
     tempstorage = fopen(STORAGE, "wb");
     if(!tempstorage) {
-        printf("Can't open temp storage file %s\n", STORAGE);
+        fprintf(stderr, "Can't open temp storage file %s\n", STORAGE);
         goto shutdown;
     }
 
@@ -171,7 +171,7 @@ int main(int argc, char *argv[])
         while ((rc = libssh2_userauth_password(session, username, password))
                == LIBSSH2_ERROR_EAGAIN);
         if (rc) {
-            printf("Authentication by password failed.\n");
+            fprintf(stderr, "Authentication by password failed.\n");
             goto shutdown;
         }
     } else {
@@ -185,7 +185,7 @@ int main(int argc, char *argv[])
                                                     password)) ==
                LIBSSH2_ERROR_EAGAIN);
         if (rc) {
-            printf("\tAuthentication by public key failed\n");
+            fprintf(stderr, "\tAuthentication by public key failed\n");
             goto shutdown;
         }
     }
@@ -341,7 +341,7 @@ int main(int argc, char *argv[])
 #endif
     if (tempstorage)
         fclose(tempstorage);
-    printf("all done\n");
+    fprintf(stderr, "all done\n");
 
     libssh2_exit();
 

example/sftp_append.c

@@ -86,7 +86,7 @@ int main(int argc, char *argv[])
 
     local = fopen(loclfile, "rb");
     if (!local) {
-        printf("Can't local file %s\n", loclfile);
+        fprintf(stderr, "Can't open local file %s\n", loclfile);
         return -1;
     }
 
@@ -129,16 +129,16 @@ int main(int argc, char *argv[])
      * user, that's your call
      */
     fingerprint = libssh2_hostkey_hash(session, LIBSSH2_HOSTKEY_HASH_SHA1);
-    printf("Fingerprint: ");
+    fprintf(stderr, "Fingerprint: ");
     for(i = 0; i < 20; i++) {
-        printf("%02X ", (unsigned char)fingerprint[i]);
+        fprintf(stderr, "%02X ", (unsigned char)fingerprint[i]);
     }
-    printf("\n");
+    fprintf(stderr, "\n");
 
     if (auth_pw) {
         /* We could authenticate via password */
         if (libssh2_userauth_password(session, username, password)) {
-            printf("Authentication by password failed.\n");
+            fprintf(stderr, "Authentication by password failed.\n");
             goto shutdown;
         }
     } else {
@@ -147,7 +147,7 @@ int main(int argc, char *argv[])
                             "/home/username/.ssh/id_rsa.pub",
                             "/home/username/.ssh/id_rsa",
                             password)) {
-            printf("\tAuthentication by public key failed\n");
+            fprintf(stderr, "\tAuthentication by public key failed\n");
             goto shutdown;
         }
     }
@@ -174,12 +174,12 @@ int main(int argc, char *argv[])
     }
 
     if(libssh2_sftp_fstat_ex(sftp_handle, &attrs, 0) < 0) {
-        printf("libssh2_sftp_fstat_ex failed\n");
+        fprintf(stderr, "libssh2_sftp_fstat_ex failed\n");
         goto shutdown;
     }
     else
         libssh2_sftp_seek64(sftp_handle, attrs.filesize);
-    printf("Did a seek to position %ld\n", (long) attrs.filesize);
+    fprintf(stderr, "Did a seek to position %ld\n", (long) attrs.filesize);
 
     fprintf(stderr, "libssh2_sftp_open() a handle for APPEND\n");
 
@@ -222,7 +222,7 @@ shutdown:
 #endif
     if (local)
         fclose(local);
-    printf("all done\n");
+    fprintf(stderr, "all done\n");
 
     libssh2_exit();
 

example/sftp_mkdir.c

@@ -110,16 +110,16 @@ int main(int argc, char *argv[])
      * user, that's your call
      */
     fingerprint = libssh2_hostkey_hash(session, LIBSSH2_HOSTKEY_HASH_SHA1);
-    printf("Fingerprint: ");
+    fprintf(stderr, "Fingerprint: ");
     for(i = 0; i < 20; i++) {
-        printf("%02X ", (unsigned char)fingerprint[i]);
+        fprintf(stderr, "%02X ", (unsigned char)fingerprint[i]);
     }
-    printf("\n");
+    fprintf(stderr, "\n");
 
     if (auth_pw) {
         /* We could authenticate via password */
         if (libssh2_userauth_password(session, username, password)) {
-            printf("Authentication by password failed.\n");
+            fprintf(stderr, "Authentication by password failed.\n");
             goto shutdown;
         }
     } else {
@@ -128,7 +128,7 @@ int main(int argc, char *argv[])
                             "/home/username/.ssh/id_rsa.pub",
                             "/home/username/.ssh/id_rsa",
                             password)) {
-            printf("\tAuthentication by public key failed\n");
+            fprintf(stderr, "\tAuthentication by public key failed\n");
             goto shutdown;
         }
     }
@@ -164,7 +164,7 @@ int main(int argc, char *argv[])
 #else
     close(sock);
 #endif
-    printf("all done\n");
+    fprintf(stderr, "all done\n");
 
     libssh2_exit();
 

example/sftp_mkdir_nonblock.c

@@ -110,16 +110,16 @@ int main(int argc, char *argv[])
      * user, that's your call
      */
     fingerprint = libssh2_hostkey_hash(session, LIBSSH2_HOSTKEY_HASH_SHA1);
-    printf("Fingerprint: ");
+    fprintf(stderr, "Fingerprint: ");
     for(i = 0; i < 20; i++) {
-        printf("%02X ", (unsigned char)fingerprint[i]);
+        fprintf(stderr, "%02X ", (unsigned char)fingerprint[i]);
     }
-    printf("\n");
+    fprintf(stderr, "\n");
 
     if (auth_pw) {
         /* We could authenticate via password */
         if (libssh2_userauth_password(session, username, password)) {
-            printf("Authentication by password failed.\n");
+            fprintf(stderr, "Authentication by password failed.\n");
             goto shutdown;
         }
     } else {
@@ -128,7 +128,7 @@ int main(int argc, char *argv[])
                             "/home/username/.ssh/id_rsa.pub",
                             "/home/username/.ssh/id_rsa",
                             password)) {
-            printf("\tAuthentication by public key failed\n");
+            fprintf(stderr, "\tAuthentication by public key failed\n");
             goto shutdown;
         }
     }
@@ -164,7 +164,7 @@ int main(int argc, char *argv[])
 #else
     close(sock);
 #endif
-    printf("all done\n");
+    fprintf(stderr, "all done\n");
 
     libssh2_exit();
 

example/sftp_nonblock.c

@@ -251,7 +251,7 @@ int main(int argc, char *argv[])
 
     gettimeofday(&end, NULL);
     time_ms = tvdiff(end, start);
-    printf("Got %d bytes in %ld ms = %.1f bytes/sec spin: %d\n", total,
+    fprintf(stderr, "Got %d bytes in %ld ms = %.1f bytes/sec spin: %d\n", total,
            time_ms, total/(time_ms/1000.0), spin );
 
     libssh2_sftp_close(sftp_handle);
@@ -259,7 +259,7 @@ int main(int argc, char *argv[])
 
 shutdown:
 
-    printf("libssh2_session_disconnect\n");
+    fprintf(stderr, "libssh2_session_disconnect\n");
     while (libssh2_session_disconnect(session,
                                       "Normal Shutdown, Thank you") ==
            LIBSSH2_ERROR_EAGAIN);

example/sftp_write.c

@@ -85,7 +85,7 @@ int main(int argc, char *argv[])
 
     local = fopen(loclfile, "rb");
     if (!local) {
-        printf("Can't local file %s\n", loclfile);
+        fprintf(stderr, "Can't open local file %s\n", loclfile);
         return -1;
     }
 
@@ -128,16 +128,16 @@ int main(int argc, char *argv[])
      * user, that's your call
      */
     fingerprint = libssh2_hostkey_hash(session, LIBSSH2_HOSTKEY_HASH_SHA1);
-    printf("Fingerprint: ");
+    fprintf(stderr, "Fingerprint: ");
     for(i = 0; i < 20; i++) {
-        printf("%02X ", (unsigned char)fingerprint[i]);
+        fprintf(stderr, "%02X ", (unsigned char)fingerprint[i]);
     }
-    printf("\n");
+    fprintf(stderr, "\n");
 
     if (auth_pw) {
         /* We could authenticate via password */
         if (libssh2_userauth_password(session, username, password)) {
-            printf("Authentication by password failed.\n");
+            fprintf(stderr, "Authentication by password failed.\n");
             goto shutdown;
         }
     } else {
@@ -146,7 +146,7 @@ int main(int argc, char *argv[])
                             "/home/username/.ssh/id_rsa.pub",
                             "/home/username/.ssh/id_rsa",
                             password)) {
-            printf("\tAuthentication by public key failed\n");
+            fprintf(stderr, "\tAuthentication by public key failed\n");
             goto shutdown;
         }
     }
@@ -206,7 +206,7 @@ shutdown:
 #endif
     if (local)
         fclose(local);
-    printf("all done\n");
+    fprintf(stderr, "all done\n");
 
     libssh2_exit();
 

example/sftp_write_nonblock.c

@@ -125,7 +125,7 @@ int main(int argc, char *argv[])
 
     local = fopen(loclfile, "rb");
     if (!local) {
-        printf("Can't local file %s\n", loclfile);
+        fprintf(stderr, "Can't open local file %s\n", loclfile);
         return -1;
     }
 
@@ -169,18 +169,18 @@ int main(int argc, char *argv[])
      * that's your call
      */
     fingerprint = libssh2_hostkey_hash(session, LIBSSH2_HOSTKEY_HASH_SHA1);
-    printf("Fingerprint: ");
+    fprintf(stderr, "Fingerprint: ");
     for(i = 0; i < 20; i++) {
-        printf("%02X ", (unsigned char)fingerprint[i]);
+        fprintf(stderr, "%02X ", (unsigned char)fingerprint[i]);
     }
-    printf("\n");
+    fprintf(stderr, "\n");
 
     if (auth_pw) {
         /* We could authenticate via password */
         while ((rc = libssh2_userauth_password(session, username, password)) ==
                LIBSSH2_ERROR_EAGAIN);
         if (rc) {
-            printf("Authentication by password failed.\n");
+            fprintf(stderr, "Authentication by password failed.\n");
             goto shutdown;
         }
     } else {
@@ -191,7 +191,7 @@ int main(int argc, char *argv[])
                                                          password)) ==
                LIBSSH2_ERROR_EAGAIN);
     if (rc) {
-            printf("\tAuthentication by public key failed\n");
+            fprintf(stderr, "\tAuthentication by public key failed\n");
             goto shutdown;
         }
     }
@@ -253,7 +253,7 @@ int main(int argc, char *argv[])
 
     duration = (int)(time(NULL)-start);
 
-    printf("%ld bytes in %d seconds makes %.1f bytes/sec\n",
+    fprintf(stderr, "%ld bytes in %d seconds makes %.1f bytes/sec\n",
            total, duration, total/(double)duration);
 
 
@@ -272,7 +272,7 @@ shutdown:
 #else
     close(sock);
 #endif
-    printf("all done\n");
+    fprintf(stderr, "all done\n");
 
     libssh2_exit();
 

example/sftp_write_sliding.c

@@ -125,7 +125,7 @@ int main(int argc, char *argv[])
 
     local = fopen(loclfile, "rb");
     if (!local) {
-        printf("Can't local file %s\n", loclfile);
+        fprintf(stderr, "Can't open local file %s\n", loclfile);
         return -1;
     }
 
@@ -169,18 +169,18 @@ int main(int argc, char *argv[])
      * that's your call
      */
     fingerprint = libssh2_hostkey_hash(session, LIBSSH2_HOSTKEY_HASH_SHA1);
-    printf("Fingerprint: ");
+    fprintf(stderr, "Fingerprint: ");
     for(i = 0; i < 20; i++) {
-        printf("%02X ", (unsigned char)fingerprint[i]);
+        fprintf(stderr, "%02X ", (unsigned char)fingerprint[i]);
     }
-    printf("\n");
+    fprintf(stderr, "\n");
 
     if (auth_pw) {
         /* We could authenticate via password */
         while ((rc = libssh2_userauth_password(session, username, password)) ==
                LIBSSH2_ERROR_EAGAIN);
         if (rc) {
-            printf("Authentication by password failed.\n");
+            fprintf(stderr, "Authentication by password failed.\n");
             goto shutdown;
         }
     } else {
@@ -191,7 +191,7 @@ int main(int argc, char *argv[])
                                                          password)) ==
                LIBSSH2_ERROR_EAGAIN);
     if (rc) {
-            printf("\tAuthentication by public key failed\n");
+            fprintf(stderr, "\tAuthentication by public key failed\n");
             goto shutdown;
         }
     }
@@ -262,7 +262,7 @@ int main(int argc, char *argv[])
 
     duration = (int)(time(NULL)-start);
 
-    printf("%ld bytes in %d seconds makes %.1f bytes/sec\n",
+    fprintf(stderr, "%ld bytes in %d seconds makes %.1f bytes/sec\n",
            total, duration, total/(double)duration);
 
 
@@ -281,7 +281,7 @@ shutdown:
 #else
     close(sock);
 #endif
-    printf("all done\n");
+    fprintf(stderr, "all done\n");
 
     libssh2_exit();
 

example/sftpdir.c

@@ -130,16 +130,16 @@ int main(int argc, char *argv[])
      * user, that's your call
      */
     fingerprint = libssh2_hostkey_hash(session, LIBSSH2_HOSTKEY_HASH_SHA1);
-    printf("Fingerprint: ");
+    fprintf(stderr, "Fingerprint: ");
     for(i = 0; i < 20; i++) {
-        printf("%02X ", (unsigned char)fingerprint[i]);
+        fprintf(stderr, "%02X ", (unsigned char)fingerprint[i]);
     }
-    printf("\n");
+    fprintf(stderr, "\n");
 
     if (auth_pw) {
         /* We could authenticate via password */
         if (libssh2_userauth_password(session, username, password)) {
-            printf("Authentication by password failed.\n");
+            fprintf(stderr, "Authentication by password failed.\n");
             goto shutdown;
         }
     } else {
@@ -148,7 +148,7 @@ int main(int argc, char *argv[])
                             "/home/username/.ssh/id_rsa.pub",
                             "/home/username/.ssh/id_rsa",
                             password)) {
-            printf("\tAuthentication by public key failed\n");
+            fprintf(stderr, "\tAuthentication by public key failed\n");
             goto shutdown;
         }
     }
@@ -229,7 +229,7 @@ int main(int argc, char *argv[])
 #else
     close(sock);
 #endif
-    printf("all done\n");
+    fprintf(stderr, "all done\n");
 
     libssh2_exit();
 

example/sftpdir_nonblock.c

@@ -134,11 +134,11 @@ int main(int argc, char *argv[])
      * user, that's your call
      */
     fingerprint = libssh2_hostkey_hash(session, LIBSSH2_HOSTKEY_HASH_SHA1);
-    printf("Fingerprint: ");
+    fprintf(stderr, "Fingerprint: ");
     for(i = 0; i < 20; i++) {
-        printf("%02X ", (unsigned char)fingerprint[i]);
+        fprintf(stderr, "%02X ", (unsigned char)fingerprint[i]);
     }
-    printf("\n");
+    fprintf(stderr, "\n");
 
     if (auth_pw) {
         /* We could authenticate via password */
@@ -239,7 +239,7 @@ int main(int argc, char *argv[])
 #else
     close(sock);
 #endif
-    printf("all done\n");
+    fprintf(stderr, "all done\n");
 
     libssh2_exit();
 

example/ssh2.c

@@ -126,15 +126,15 @@ int main(int argc, char *argv[])
      * call
      */
     fingerprint = libssh2_hostkey_hash(session, LIBSSH2_HOSTKEY_HASH_SHA1);
-    printf("Fingerprint: ");
+    fprintf(stderr, "Fingerprint: ");
     for(i = 0; i < 20; i++) {
-        printf("%02X ", (unsigned char)fingerprint[i]);
+        fprintf(stderr, "%02X ", (unsigned char)fingerprint[i]);
     }
-    printf("\n");
+    fprintf(stderr, "\n");
 
     /* check what authentication methods are available */
     userauthlist = libssh2_userauth_list(session, username, strlen(username));
-    printf("Authentication methods: %s\n", userauthlist);
+    fprintf(stderr, "Authentication methods: %s\n", userauthlist);
     if (strstr(userauthlist, "password") != NULL) {
         auth_pw |= 1;
     }
@@ -161,31 +161,33 @@ int main(int argc, char *argv[])
     if (auth_pw & 1) {
         /* We could authenticate via password */
         if (libssh2_userauth_password(session, username, password)) {
-            printf("\tAuthentication by password failed!\n");
+            fprintf(stderr, "\tAuthentication by password failed!\n");
             goto shutdown;
         } else {
-            printf("\tAuthentication by password succeeded.\n");
+            fprintf(stderr, "\tAuthentication by password succeeded.\n");
         }
     } else if (auth_pw & 2) {
         /* Or via keyboard-interactive */
         if (libssh2_userauth_keyboard_interactive(session, username,
                                                   &kbd_callback) ) {
-            printf("\tAuthentication by keyboard-interactive failed!\n");
+            fprintf(stderr,
+                "\tAuthentication by keyboard-interactive failed!\n");
             goto shutdown;
         } else {
-            printf("\tAuthentication by keyboard-interactive succeeded.\n");
+            fprintf(stderr,
+                "\tAuthentication by keyboard-interactive succeeded.\n");
         }
     } else if (auth_pw & 4) {
         /* Or by public key */
         if (libssh2_userauth_publickey_fromfile(session, username, keyfile1,
                                                 keyfile2, password)) {
-            printf("\tAuthentication by public key failed!\n");
+            fprintf(stderr, "\tAuthentication by public key failed!\n");
             goto shutdown;
         } else {
-            printf("\tAuthentication by public key succeeded.\n");
+            fprintf(stderr, "\tAuthentication by public key succeeded.\n");
         }
     } else {
-        printf("No supported authentication methods found!\n");
+        fprintf(stderr, "No supported authentication methods found!\n");
         goto shutdown;
     }
 
@@ -250,7 +252,7 @@ int main(int argc, char *argv[])
 #else
     close(sock);
 #endif
-    printf("all done!\n");
+    fprintf(stderr, "all done!\n");
 
     libssh2_exit();
 

example/ssh2_agent.c

@@ -105,15 +105,15 @@ int main(int argc, char *argv[])
      * call
      */
     fingerprint = libssh2_hostkey_hash(session, LIBSSH2_HOSTKEY_HASH_SHA1);
-    printf("Fingerprint: ");
+    fprintf(stderr, "Fingerprint: ");
     for(i = 0; i < 20; i++) {
-        printf("%02X ", (unsigned char)fingerprint[i]);
+        fprintf(stderr, "%02X ", (unsigned char)fingerprint[i]);
     }
-    printf("\n");
+    fprintf(stderr, "\n");
 
     /* check what authentication methods are available */
     userauthlist = libssh2_userauth_list(session, username, strlen(username));
-    printf("Authentication methods: %s\n", userauthlist);
+    fprintf(stderr, "Authentication methods: %s\n", userauthlist);
     if (strstr(userauthlist, "publickey") == NULL) {
         fprintf(stderr, "\"publickey\" authentication is not supported\n");
         goto shutdown;
@@ -147,11 +147,11 @@ int main(int argc, char *argv[])
             goto shutdown;
         }
         if (libssh2_agent_userauth(agent, username, identity)) {
-            printf("\tAuthentication with username %s and "
+            fprintf(stderr, "\tAuthentication with username %s and "
                    "public key %s failed!\n",
                    username, identity->comment);
         } else {
-            printf("\tAuthentication with username %s and "
+            fprintf(stderr, "\tAuthentication with username %s and "
                    "public key %s succeeded!\n",
                    username, identity->comment);
             break;
@@ -234,7 +234,7 @@ int main(int argc, char *argv[])
 #endif
     }
 
-    printf("all done!\n");
+    fprintf(stderr, "all done!\n");
 
     libssh2_exit();
 

example/ssh2_echo.c

@@ -327,7 +327,7 @@ int main(int argc, char *argv[])
         }
 
         if (exitsignal)
-            printf("\nGot signal: %s\n", exitsignal);
+            fprintf(stderr, "\nGot signal: %s\n", exitsignal);
 
         libssh2_channel_free(channel);
         channel = NULL;

example/ssh2_exec.c

@@ -292,9 +292,9 @@ int main(int argc, char *argv[])
     }
 
     if (exitsignal)
-        printf("\nGot signal: %s\n", exitsignal);
+        fprintf(stderr, "\nGot signal: %s\n", exitsignal);
     else 
-        printf("\nEXIT: %d bytecount: %d\n", exitcode, bytecount);
+        fprintf(stderr, "\nEXIT: %d bytecount: %d\n", exitcode, bytecount);
 
     libssh2_channel_free(channel);
     channel = NULL;

example/subsystem_netconf.c

@@ -173,7 +173,7 @@ int main(int argc, char *argv[])
 
     /* check what authentication methods are available */
     userauthlist = libssh2_userauth_list(session, username, strlen(username));
-    printf("Authentication methods: %s\n", userauthlist);
+    fprintf(stderr, "Authentication methods: %s\n", userauthlist);
     if (strstr(userauthlist, "password"))
         auth |= AUTH_PASSWORD;
     if (strstr(userauthlist, "publickey"))
@@ -195,12 +195,12 @@ int main(int argc, char *argv[])
     } else if (auth & AUTH_PUBLICKEY) {
         if (libssh2_userauth_publickey_fromfile(session, username, keyfile1,
                                                 keyfile2, password)) {
-            printf("Authentication by public key failed!\n");
+            fprintf(stderr, "Authentication by public key failed!\n");
             goto shutdown;
         }
-        printf("Authentication by public key succeeded.\n");
+        fprintf(stderr, "Authentication by public key succeeded.\n");
     } else {
-        printf("No supported authentication methods found!\n");
+        fprintf(stderr, "No supported authentication methods found!\n");
         goto shutdown;
     }
 
@@ -223,7 +223,7 @@ int main(int argc, char *argv[])
 
     /* NETCONF: http://tools.ietf.org/html/draft-ietf-netconf-ssh-06 */
 
-    printf("Sending NETCONF client <hello>\n");
+    fprintf(stderr, "Sending NETCONF client <hello>\n");
     snprintf(buf, sizeof(buf),
       "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n"
       "<hello>"
@@ -235,14 +235,14 @@ int main(int argc, char *argv[])
     if (-1 == netconf_write(channel, buf, len))
         goto shutdown;
 
-    printf("Reading NETCONF server <hello>\n");
+    fprintf(stderr, "Reading NETCONF server <hello>\n");
     len = netconf_read_until(channel, "</hello>", buf, sizeof(buf));
     if (-1 == len)
         goto shutdown;
 
-    printf("Got %d bytes:\n----------------------\n%s", (int)len, buf);
+    fprintf(stderr, "Got %d bytes:\n----------------------\n%s", (int)len, buf);
 
-    printf("Sending NETCONF <rpc>\n");
+    fprintf(stderr, "Sending NETCONF <rpc>\n");
     snprintf(buf, sizeof(buf),
       "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n"
       "<rpc xmlns=\"urn:ietf:params:xml:ns:netconf:base:1.0\">"
@@ -252,12 +252,12 @@ int main(int argc, char *argv[])
     if (-1 == netconf_write(channel, buf, len))
         goto shutdown;
 
-    printf("Reading NETCONF <rpc-reply>\n");
+    fprintf(stderr, "Reading NETCONF <rpc-reply>\n");
     len = netconf_read_until(channel, "</rpc-reply>", buf, sizeof(buf));
     if (-1 == len)
         goto shutdown;
 
-    printf("Got %d bytes:\n----------------------\n%s", (int)len, buf);
+    fprintf(stderr, "Got %d bytes:\n----------------------\n%s", (int)len, buf);
 
 shutdown:
     if (channel)

example/tcpip-forward.c

@@ -137,7 +137,7 @@ int main(int argc, char *argv[])
 
     /* check what authentication methods are available */
     userauthlist = libssh2_userauth_list(session, username, strlen(username));
-    printf("Authentication methods: %s\n", userauthlist);
+    fprintf(stderr, "Authentication methods: %s\n", userauthlist);
     if (strstr(userauthlist, "password"))
         auth |= AUTH_PASSWORD;
     if (strstr(userauthlist, "publickey"))
@@ -159,17 +159,17 @@ int main(int argc, char *argv[])
     } else if (auth & AUTH_PUBLICKEY) {
         if (libssh2_userauth_publickey_fromfile(session, username, keyfile1,
                                                 keyfile2, password)) {
-            printf("\tAuthentication by public key failed!\n");
+            fprintf(stderr, "\tAuthentication by public key failed!\n");
             goto shutdown;
         }
-        printf("\tAuthentication by public key succeeded.\n");
+        fprintf(stderr, "\tAuthentication by public key succeeded.\n");
     } else {
-        printf("No supported authentication methods found!\n");
+        fprintf(stderr, "No supported authentication methods found!\n");
         goto shutdown;
     }
 
-    printf("Asking server to listen on remote %s:%d\n", remote_listenhost,
+    fprintf(stderr, "Asking server to listen on remote %s:%d\n",
-        remote_wantport);
+        remote_listenhost, remote_wantport);
 
     listener = libssh2_channel_forward_listen_ex(session, remote_listenhost,
         remote_wantport, &remote_listenport, 1);
@@ -180,10 +180,10 @@ int main(int argc, char *argv[])
         goto shutdown;
     }
 
-    printf("Server is listening on %s:%d\n", remote_listenhost,
+    fprintf(stderr, "Server is listening on %s:%d\n", remote_listenhost,
         remote_listenport);
 
-    printf("Waiting for remote connection\n");
+    fprintf(stderr, "Waiting for remote connection\n");
     channel = libssh2_channel_forward_accept(listener);
     if (!channel) {
         fprintf(stderr, "Could not accept connection!\n"
@@ -192,7 +192,8 @@ int main(int argc, char *argv[])
         goto shutdown;
     }
 
-    printf("Accepted remote connection. Connecting to local server %s:%d\n",
+    fprintf(stderr,
+        "Accepted remote connection. Connecting to local server %s:%d\n",
         local_destip, local_destport);
     forwardsock = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);
     sin.sin_family = AF_INET;
@@ -206,7 +207,7 @@ int main(int argc, char *argv[])
         goto shutdown;
     }
 
-    printf("Forwarding connection from remote %s:%d to local %s:%d\n",
+    fprintf(stderr, "Forwarding connection from remote %s:%d to local %s:%d\n",
         remote_listenhost, remote_listenport, local_destip, local_destport);
 
     /* Must use non-blocking IO hereafter due to the current libssh2 API */
@@ -228,7 +229,7 @@ int main(int argc, char *argv[])
                 perror("read");
                 goto shutdown;
             } else if (0 == len) {
-                printf("The local server at %s:%d disconnected!\n",
+                fprintf(stderr, "The local server at %s:%d disconnected!\n",
                     local_destip, local_destport);
                 goto shutdown;
             }
@@ -260,7 +261,7 @@ int main(int argc, char *argv[])
                 wr += i;
             }
             if (libssh2_channel_eof(channel)) {
-                printf("The remote client at %s:%d disconnected!\n",
+                fprintf(stderr, "The remote client at %s:%d disconnected!\n",
                     remote_listenhost, remote_listenport);
                 goto shutdown;
             }