Save file update (incomplete)

src/dusklinux/save/savestreamlinux.c

@@ -0,0 +1,75 @@
+/**
+ * Copyright (c) 2026 Dominic Masters
+ *
+ * This software is released under the MIT License.
+ * https://opensource.org/licenses/MIT
+ */
+
+#include "save/save.h"
+#include "save/savestreamlinux.h"
+#include "util/string.h"
+#include <sys/stat.h>
+#include <errno.h>
+
+static void _saveStreamGetPath(
+  char_t *out, const size_t max, const uint8_t slot
+) {
+  snprintf(
+    out, max, SAVE_LINUX_FILE_FORMAT,
+    SAVE.platform.savePath, (uint32_t)slot
+  );
+}
+
+errorret_t saveStreamOpenReadLinux(
+  savestreamlinux_t *p, bool_t *found, const uint8_t slot
+) {
+  char_t path[SAVE_LINUX_PATH_MAX];
+  _saveStreamGetPath(path, SAVE_LINUX_PATH_MAX, slot);
+
+  p->file = fopen(path, "rb");
+  *found = (p->file != NULL);
+  errorOk();
+}
+
+errorret_t saveStreamOpenWriteLinux(savestreamlinux_t *p, const uint8_t slot) {
+  char_t path[SAVE_LINUX_PATH_MAX];
+  _saveStreamGetPath(path, SAVE_LINUX_PATH_MAX, slot);
+
+  p->file = fopen(path, "wb");
+  if(!p->file) {
+    errorThrow("Failed to open save file for writing: slot %u", (uint32_t)slot);
+  }
+  errorOk();
+}
+
+void saveStreamCloseLinux(savestreamlinux_t *p) {
+  if(p->file) {
+    fclose(p->file);
+    p->file = NULL;
+  }
+}
+
+errorret_t saveStreamReadBytesLinux(
+  savestreamlinux_t *p, void *buf, const size_t len
+) {
+  if(fread(buf, 1, len, p->file) != len) {
+    errorThrow("Unexpected end of save file");
+  }
+  errorOk();
+}
+
+errorret_t saveStreamWriteBytesLinux(
+  savestreamlinux_t *p, const void *buf, const size_t len
+) {
+  if(fwrite(buf, 1, len, p->file) != len) {
+    errorThrow("Failed to write save data");
+  }
+  errorOk();
+}
+
+errorret_t saveStreamSeekLinux(savestreamlinux_t *p, const size_t pos) {
+  if(fseek(p->file, (long)pos, SEEK_SET) != 0) {
+    errorThrow("Failed to seek in save file");
+  }
+  errorOk();
+}