_strdup, _wcsdup, _mbsdup
Duplicate strings.
char*_strdup(constchar*strSource);
wchar_t*_wcsdup(constwchar_t*strSource);
unsignedchar*_mbsdup(constunsignedchar*strSource);
| Routine | Required Header | Compatibility |
| _strdup | <string.h> | Win 95, Win NT |
| _wcsdup | <string.h> or <wchar.h> | Win 95, Win NT |
| _mbsdup | <mbstring.h> | Win 95, Win NT |
For additional compatibility information, see Compatibility in the Introduction.
Libraries
| LIBC.LIB | Single thread static library, retail version |
| LIBCMT.LIB | Multithread static library, retail version |
| MSVCRT.LIB | Import library for MSVCRT.DLL, retail version |
Return Value
Each of these functions returns a pointer to the storage location for the copied string or NULL if storage cannot be allocated.
Parameter
strSource
Null-terminated source string
Remarks
The _strdup function calls malloc to allocate storage space for a copy of strSource and then copies strSource to the allocated space.
_wcsdup and _mbsdup are wide-character and multibyte-character versions of _strdup. The arguments and return value of _wcsdup are wide-character strings; those of _mbsdup are multibyte-character strings. These three functions behave identically otherwise.
Generic-Text Routine Mappings
| TCHAR.H Routine | _UNICODE & _MBCS Not Defined | _MBCS Defined | _UNICODE Defined |
| _tcsdup | _strdup | _mbsdup | _wcsdup |
Because _strdup calls malloc to allocate storage space for the copy of strSource, it is good practice always to release this memory by calling the free routine on the pointer returned by the call to _strdup.
Example
/* STRDUP.C */
#include <string.h>
#include <stdio.h>
void main( void )
{
char buffer[] = "This is the buffer text";
char *newstring;
printf( "Original: %s\n", buffer );
newstring = _strdup( buffer );
printf( "Copy: %s\n", newstring );
free( newstring );
}
Output
Original: This is the buffer text
Copy: This is the buffer text
See Also memset, strcat, strcmp, strncat, strncmp, strncpy, _strnicmp, strrchr, strspn