StringCchCopy
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8/27/2008
This function is a replacement for strcpy.
The size, in characters, of the destination buffer is provided to the function to ensure that StringCchCopy does not write past the end of this buffer.
Syntax
HRESULT StringCchCopy(
LPTSTR pszDest,
size_t cchDest,
LPCTSTR pszSrc
);
Parameters
- pszDest
[out] Pointer to a buffer that receives the copied string.
cchDest
[in] Size of the destination buffer, in characters.This value must equal the length of pszSrc, plus 1 to account for the copied source string and the terminating null character.
The maximum number of characters allowed is STRSAFE_MAX_CCH.
pszSrc
[in] Pointer to a buffer containing the source string.This source string must be null-terminated.
Return Value
This function returns an HRESULT, as opposed to strcpy, which returns a pointer.
It is strongly recommended that you use the SUCCEEDED and FAILED macros to test the return value of this function.
| Value | Description |
|---|---|
S_OK |
Source data was present, fully copied without truncation, and the resultant destination buffer is null-terminated. |
STRSAFE_E_INVALID_PARAMETER |
The value in cchDest is 0 or larger than STRSAFE_MAX_CCH. |
STRSAFE_E_INSUFFICIENT_BUFFER |
The copy operation failed due to insufficient buffer space. The destination buffer contains a truncated, null-terminated version of the intended result. Where truncation is acceptable, this is not necessarily a failure condition. |
Remarks
StringCchCopy provides additional processing for proper buffer handling in your code.
Poor buffer handling is implicated in many security issues that involve buffer overruns. StringCchCopy always null-terminates a nonzero-length destination buffer.
StringCchCopy can be used in its generic form, or specifically as StringCchCopyA (for ANSI strings) or StringCchCopyW (for Unicode strings). The form to use is determined by your data.
| String data type | String literal | Function |
|---|---|---|
char |
"string" |
StringCchCopyA |
TCHAR |
TEXT("string") |
StringCchCopy |
WCHAR |
L"string" |
StringCchCopyW |
StringCchCopy and its ANSI and Unicode variants are replacements for these functions:
- strcpy
- wcscpy
This function is not a replacement for strncpy due to differences in behavior, and errors might result if you make that replacement. To replace strncpy, use StringCchCopyN or StringCchCopyNEx..
If the strings pointed to by pszSrc and pszDest overlap, behavior is undefined.
Neither pszSrc nor pszDest should be NULL.
If you need the handling of null string pointer values, see StringCchCopyEx.
Requirements
| Header | strsafe.h |
| Windows Embedded CE | Windows CE 5.0 and later |