[Feature] Add per-gpu mode switch in CLI

README.md

@@ -15,6 +15,7 @@ NVFD is an open-source NVIDIA GPU fan control daemon for Linux. It uses the NVML
 - Fixed fan speed mode
 - True auto mode (returns control to NVIDIA driver)
 - Multi-GPU support with per-GPU or all-GPU control, adaptive full/tabbed display
+- Per-GPU mode switching via CLI (`nvfd 0 auto`, `nvfd 1 curve`, etc.)
 - Real-time temperature, utilization, memory, and power monitoring
 - Systemd service with automatic fan reset on shutdown
 - Config hot-reload via SIGHUP
@@ -110,6 +111,9 @@ nvfd curve edit            Interactive curve editor (ncurses)
 nvfd curve reset           Reset fan curve to default
 nvfd <speed>               Set fixed fan speed for all GPUs (30-100)
 nvfd <gpu_index> <speed>   Set fixed fan speed for specific GPU
+nvfd <gpu_index> auto      Set specific GPU to auto mode
+nvfd <gpu_index> curve     Set specific GPU to curve mode
+nvfd <gpu_index> manual <speed>  Set specific GPU to fixed speed
 nvfd list                  List all GPUs and their indices
 nvfd status                Show current status
 nvfd -h                    Show help
@@ -169,6 +173,11 @@ nvfd 0 60
 # Return all fans to driver control
 nvfd auto
 
+# Per-GPU mode control
+nvfd 0 auto          # Set GPU 0 to auto mode
+nvfd 1 curve         # Set GPU 1 to curve mode
+nvfd 0 manual 70     # Set GPU 0 to manual mode at 70%
+
 # Use custom fan curve
 nvfd curve
 nvfd curve show

src/display.c

@@ -30,6 +30,12 @@ void display_help(void) {
     printf("+-----------------------------+-----------------------------------------+\n");
     printf("| nvfd <gpu_index> <speed>    | Set fixed fan speed for specific GPU    |\n");
     printf("+-----------------------------+-----------------------------------------+\n");
+    printf("| nvfd <gpu_index> auto       | Set specific GPU to auto mode           |\n");
+    printf("+-----------------------------+-----------------------------------------+\n");
+    printf("| nvfd <gpu_index> curve      | Set specific GPU to curve mode          |\n");
+    printf("+-----------------------------+-----------------------------------------+\n");
+    printf("| nvfd <gpu_index> manual <sp>  Set specific GPU to fixed speed         |\n");
+    printf("+-----------------------------+-----------------------------------------+\n");
     printf("| nvfd list                   | List all GPUs and their indices         |\n");
     printf("+-----------------------------+-----------------------------------------+\n");
     printf("| nvfd status                 | Show current status                     |\n");

src/main.c

@@ -236,6 +236,49 @@ int main(int argc, char *argv[]) {
             } else {
                 printf("Invalid GPU index. Use 'nvfd list' to see available GPUs.\n");
             }
+        } else if (argc == 3 && gpu_index >= 0 && gpu_index < (int)device_count) {
+            /* Per-GPU mode: nvfd <gpu_index> auto|curve */
+            if (strcmp(argv[2], "auto") == 0) {
+                char gpu_key[20];
+                snprintf(gpu_key, sizeof(gpu_key), "gpu%d", gpu_index);
+                config_write_gpu(gpu_key, "auto", 0);
+                fan_reset_to_auto((unsigned int)gpu_index);
+                printf("GPU %d set to auto mode (driver-controlled).\n", gpu_index);
+            } else if (strcmp(argv[2], "curve") == 0) {
+                char gpu_key[20];
+                snprintf(gpu_key, sizeof(gpu_key), "gpu%d", gpu_index);
+                config_write_gpu(gpu_key, "curve", 0);
+                printf("GPU %d set to curve mode.\n", gpu_index);
+            } else if (strcmp(argv[2], "manual") == 0) {
+                printf("Invalid command. Use 'nvfd <gpu_index> manual <speed>' for manual mode.\n");
+                display_help();
+                gpu_shutdown();
+                return 1;
+            } else {
+                printf("Invalid command or arguments.\n");
+                display_help();
+            }
+        } else if (argc == 4) {
+            /* Per-GPU manual mode: nvfd <gpu_index> manual <speed> */
+            gpu_index = atoi(argv[1]);
+            if (strcmp(argv[2], "manual") == 0 && gpu_index >= 0 && gpu_index < (int)device_count) {
+                speed = atoi(argv[3]);
+                if (speed >= 30 && speed <= 100) {
+                    char gpu_key[20];
+                    snprintf(gpu_key, sizeof(gpu_key), "gpu%d", gpu_index);
+                    config_write_gpu(gpu_key, "manual", speed);
+                    fan_set_gpu_speed((unsigned int)gpu_index, (unsigned int)speed);
+                    printf("GPU %d set to fixed speed %d%%.\n", gpu_index, speed);
+                } else {
+                    printf("Invalid speed. Use a value between 30 and 100.\n");
+                    display_help();
+                }
+            } else {
+                printf("Invalid command: %s\n", argv[2]);
+                display_help();
+                gpu_shutdown();
+                return 1;
+            }
         } else {
             printf("Invalid speed. Use a value between 30 and 100.\n");
             display_help();