i64 -> u64 + osFileXXX() works on both linux and mac I think

unix_os.c

@@ -99,7 +99,7 @@ fn Dim2 osGetTerminalDimensions() {
   return result;
 }
 
-void osBlitToTerminal(ptr writeable_output_ansi_string, i64 count) {
+void osBlitToTerminal(ptr writeable_output_ansi_string, u64 count) {
   int flags = fcntl(STDOUT_FILENO, F_GETFL);
   fcntl(STDOUT_FILENO, F_SETFL, flags & ~O_NONBLOCK);
 
@@ -157,3 +157,119 @@ i32 osLanIPAddress() { // returns as HOST byte-order
   }
   return result;
 }
+
+// Files
+fn bool osFileExists(String filename) {
+  bool result = access((str)filename.bytes, F_OK) == 0;
+  return result;
+}
+
+fn String osFileRead(Arena* arena, ptr filepath) {
+  struct stat st;
+  stat(filepath, &st);
+  String result = { st.st_size, st.st_size, 0 };
+  result.bytes = arenaAlloc(arena, st.st_size);
+
+  size_t handle = open(filepath, O_RDWR, S_IRUSR | S_IRGRP | S_IROTH);
+  read(handle, result.bytes, st.st_size);
+  close(handle);
+
+  return result;
+}
+
+fn bool osFileCreate(String filename) {
+  /*
+  M_Scratch scratch = scratch_get();
+  string nt = str_copy(&scratch.arena, filename);
+  bool result = true;
+  size_t handle = open((const char*) nt.str, O_RDWR | O_CREAT, S_IRUSR | S_IRGRP | S_IROTH);
+  if (handle == -1) {
+      result = false;
+  }
+  scratch_return(&scratch);
+  close(handle);
+  return true;
+  */
+  bool result = true;
+  size_t handle = open((str)filename.bytes, O_RDWR | O_CREAT, S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH);
+  if (handle == -1) {
+    result = false;
+  }
+  if (close(handle) == -1) {
+    result = false;
+  }
+  return result;
+}
+
+fn bool osFileCreateWrite(String filename, String data) {
+  /*
+  M_Scratch scratch = scratch_get();
+  string nt = str_copy(&scratch.arena, filename);
+  b32 result = true;
+  size_t handle =
+    open((const char*) nt.str, O_RDWR | O_CREAT | O_TRUNC, S_IRUSR | S_IRGRP | S_IROTH);
+  if (handle == -1) result = false;
+  write(handle, data.str, data.size);
+  close(handle);
+  scratch_return(&scratch);
+  return result;
+  */
+  bool result = true;
+  size_t handle = open(
+    (str)filename.bytes,
+    O_RDWR | O_CREAT | O_TRUNC,
+    S_IRUSR | S_IRGRP | S_IROTH
+  );
+  if (handle == -1) result = false;
+  write(handle, data.bytes, data.length);
+  close(handle);
+  return result;
+}
+
+fn bool osFileWrite(String filename, String data) {
+  /*
+    M_Scratch scratch = scratch_get();
+    string nt = str_copy(&scratch.arena, filename);
+    b32 result = true;
+    size_t handle =
+        open((const char*) nt.str, O_RDWR | O_TRUNC, S_IRUSR | S_IRGRP | S_IROTH);
+    if (handle == -1) result = false;
+    write(handle, data.str, data.size);
+    close(handle);
+  */
+  bool result = true;
+  size_t handle = open((str) filename.bytes, O_RDWR | O_TRUNC, S_IRUSR | S_IRGRP | S_IROTH);
+  if (handle == -1) result = false;
+  write(handle, data.bytes, data.length);
+  close(handle);
+  return result;
+}
+
+fn Resulti64 osFileOpenForWriting(String filename) {
+  size_t handle = open((str)filename.bytes, O_WRONLY | O_APPEND, S_IRUSR | S_IRGRP | S_IROTH);
+  Resulti64 result = {
+    .success = handle != -1,
+    .value = (i64)handle,
+  };
+  return result;
+}
+
+fn Resulti64 osFileClose(Resulti64 handle) {
+  i32 close_result = close((size_t)handle.value);
+  Resulti64 result = {
+    .success = close_result != -1,
+    .value = (i64)close_result,
+  };
+  return result;
+}
+
+fn bool osFileWriteOpenFile(Resulti64 handle, String data) {
+  assert(handle.success == true);
+  i32 wrote_this_round = 0;
+  for (i32 bytes_written = 0; bytes_written < data.length; bytes_written += wrote_this_round) {
+    wrote_this_round = write((size_t)handle.value, data.bytes + bytes_written, data.length - bytes_written);
+    if (wrote_this_round == -1) return false;
+  }
+  return true;
+}
+