---
title: "_commit | Microsoft Docs"
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ms.date: "11/04/2016"
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---
# _commit
Flushes a file directly to disk.  
  
## Syntax  
  
```  
int _commit(   
   int fd   
);  
```  
  
#### Parameters  
 `fd`  
 File descriptor referring to the open file.  
  
## Return Value  
 `_commit` returns 0 if the file was successfully flushed to disk. A return value of -1 indicates an error.  
  
## Remarks  
 The `_commit` function forces the operating system to write the file associated with `fd` to disk. This call ensures that the specified file is flushed immediately, not at the operating system's discretion.  
  
 If `fd` is an invalid file descriptor, the invalid parameter handler is invoked, as described in [Parameter Validation](../../c-runtime-library/parameter-validation.md). If execution is allowed to continue, the function returns -1 and `errno` is set to `EBADF`.  
  
## Requirements  
  
|Routine|Required header|Optional headers|  
|-------------|---------------------|----------------------|  
|`_commit`|\<io.h>|\<errno.h>|  
  
 For more compatibility information, see [Compatibility](../../c-runtime-library/compatibility.md) in the Introduction.  
  
## See Also  
 [Low-Level I/O](../../c-runtime-library/low-level-i-o.md)   
 [_creat, _wcreat](../../c-runtime-library/reference/creat-wcreat.md)   
 [_open, _wopen](../../c-runtime-library/reference/open-wopen.md)   
 [_read](../../c-runtime-library/reference/read.md)   
 [_write](../../c-runtime-library/reference/write.md)