CharToOemA function (winuser.h)

2025-07-16

Translates a string into the OEM-defined character set.

Warning Do not use. See Security Considerations.

Syntax

BOOL CharToOemA(
  [in]  LPCSTR pSrc,
  [out] LPSTR  pDst
);

Parameters

[in] pSrc

Type: LPCTSTR

The null-terminated string to be translated.

[out] pDst

Type: LPSTR

The destination buffer, which receives the translated string. If the CharToOem function is being used as an ANSI function, the string can be translated in place by setting the lpszDst parameter to the same address as the lpszSrc parameter. This cannot be done if CharToOem is being used as a wide-character function.

Return value

Type: BOOL

The return value is always nonzero except when you pass the same address to lpszSrc and lpszDst in the wide-character version of the function. In this case the function returns zero and GetLastError returns ERROR_INVALID_ADDRESS.

Remarks

Security Considerations

Using this function incorrectly might compromise the security of your program. For example, miscalculating the proper size of the lpszDst buffer, especially when the application is used in both ANSI and Unicode versions, can cause a buffer overflow. For more information, see Security Considerations: International Features and Security Considerations: Windows User Interface.

Note

The winuser.h header defines CharToOem as an alias that automatically selects the ANSI or Unicode version of this function based on the definition of the UNICODE preprocessor constant. Mixing usage of the encoding-neutral alias with code that is not encoding-neutral can lead to mismatches that result in compilation or runtime errors. For more information, see Conventions for Function Prototypes.

Requirements

Requirement	Value
Minimum supported client	Windows 2000 Professional [desktop apps only]
Minimum supported server	Windows 2000 Server [desktop apps only]
Target Platform	Windows
Header	winuser.h (include Windows.h)
Library	User32.lib
DLL	User32.dll
API set	ext-ms-win-ntuser-chartranslation-l1-1-0 (introduced in Windows 8)

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