C6067
Note
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warning C6067: parameter <number> in call to <function> must be the address of the string
This warning indicates a mismatch between the format specifier and the function parameter. Even though the warning suggests using the address of the string, you must check the type of parameter a function expects before correcting the problem. For example, a %s
specification for printf
requires a string argument, but a %s
specification in scanf
requires an address of the string.
This defect is likely to cause a crash or corruption of some form.
Example
The following code generates this warning because an integer is passed instead of a string:
#include <stdio.h>
void f_defective( )
{
char *str = "Hello, World!";
printf("String:\n %s",1); // warning
// code ...
}
To correct the warning, pass a string as a parameter to printf
as shown in the following code:
#include <stdio.h>
void f_corrected( )
{
char *str = "Hello, World!";
printf("String:\n %s",str);
// code ...
}
The following code generates this warning because an incorrect level of indirection is specified when passing the parameter, buffer, to scanf
:
#include <stdio.h>
void h_defective( )
{
int retval;
char* buffer = new char(20);
if ( buffer )
{
retval = scanf("%s", &buffer); // warning C6067
// code...
delete buffer ;
}
}
To correct above warnings, pass the correct parameter as shown in the following code:
#include <stdio.h>
void h_corrected( )
{
int retval;
char* buffer = new char(20);
if ( buffer )
{
retval = scanf("%s", buffer);
// code...
delete buffer;
}
}
The following code uses safe string manipulation functions to correct this warning:
#include <stdio.h>
void f_safe( )
{
char buff[20];
int retVal;
sprintf_s( buff, 20, "%s %s", "Hello", "World!" );
printf_s( "String:\n %s %s", "Hello", "World!" );
retVal = scanf_s("%s", buff, 20);
}
See Also
sprintf_s, _sprintf_s_l, swprintf_s, _swprintf_s_l
printf, _printf_l, wprintf, _wprintf_l
scanf_s, _scanf_s_l, wscanf_s, _wscanf_s_l