quick-wins: ControlMaster, -z alias, --progress, fix write warning

- SSH ControlMaster auto with ControlPath for connection reuse
- -z as alias for -c (compression)
- --progress flag showing transfer rate in send_files
- Fixed unused-result warning on write() in transport_ssh.c

src/client/client_cli.c

@@ -21,6 +21,8 @@ static void print_usage(void) {
   printf("\n");
   printf("Options:\n");
   printf("  -c [level]          Enable compression (level 1-22, default 5)\n");
+  printf("  -z [level]          Alias for -c\n");
+  printf("  --progress          Show transfer progress\n");
   printf("  -m                  Enable multithreading\n");
   printf("  -s                  Enable chunk serialization\n");
   printf("  -f                  Enable sendfile (TCP only, not with -c or -s)\n");
@@ -56,7 +58,7 @@ int main(int argc, char *argv[]) {
     if (strcmp(argv[i], "--help") == 0) {
       print_usage();
       return 0;
-    } else if (strcmp(argv[i], "-c") == 0) {
+    } else if (strcmp(argv[i], "-c") == 0 || strcmp(argv[i], "-z") == 0) {
       config->use_compression = true;
       log_message(LOG_LEVEL_INFO, "Enabled Compression");
       if (i + 1 < argc) {
@@ -94,6 +96,8 @@ int main(int argc, char *argv[]) {
       server_host = str_dup(argv[++i]);
     } else if (strcmp(argv[i], "--server-port") == 0 && i + 1 < argc) {
       server_port = atoi(argv[++i]);
+    } else if (strcmp(argv[i], "--progress") == 0) {
+      config->show_progress = true;
     } else if (strcmp(argv[i], "--chunk-size") == 0 && i + 1 < argc) {
       unsigned long long val = strtoull(argv[++i], NULL, 10);
       if (val > 0)

src/client/client_send.c

@@ -15,6 +15,7 @@
 #include <stdlib.h>
 #include <string.h>
 #include <threads.h>
+#include <time.h>
 
 int send_chunk(Client *client, Chunk *chunk, Config *config) {
   if (config->use_chunk_serialization) {
@@ -140,16 +141,38 @@ int send_files(Config *config) {
   config_send(client->file_descriptor, config);
   DirectoryScanner *scanner = directory_scanner_create(config->send_directory, config->use_metadata, config->chunk_size);
   Chunk *current_chunk;
+  unsigned long long total_bytes = 0;
+  time_t last_progress = 0;
+  time_t start = time(NULL);
   while ((current_chunk = directory_scanner_next(scanner)) != NULL) {
+    unsigned long long chunk_bytes = 0;
+    for (int i = 0; i < current_chunk->element_count; i++)
+      chunk_bytes += current_chunk->items[i]->data->size;
     if (!config->use_sendfile) {
       for (int i = 0; i < current_chunk->element_count; i++)
         file_load_data(current_chunk->items[i]);
     }
     send_chunk(client, current_chunk, config);
+    if (config->show_progress) {
+      total_bytes += chunk_bytes;
+      time_t now = time(NULL);
+      if (now - last_progress >= 1) {
+        last_progress = now;
+        double elapsed = difftime(now, start);
+        double rate = elapsed > 0 ? total_bytes / (1048576.0 * elapsed) : 0;
+        fprintf(stderr, "\rSent %.1f MB  (%.1f MB/s)  ", total_bytes / 1048576.0, rate);
+        fflush(stderr);
+      }
+    }
     chunk_destroy(current_chunk);
   }
   send_status(client->file_descriptor, STATUS_FINISHED);
   int ok = receive_status(client->file_descriptor) == STATUS_OK;
+  if (config->show_progress) {
+    double elapsed = difftime(time(NULL), start);
+    double rate = elapsed > 0 ? total_bytes / (1048576.0 * elapsed) : 0;
+    fprintf(stderr, "\rSent %.1f MB  (%.1f MB/s)  Done.\n", total_bytes / 1048576.0, rate);
+  }
   directory_scanner_destroy(scanner);
   client_disconnect(client);
   client_delete(client);