Thread: comparing strings using argv

I have a little test program looking for a way to best compare strings from argv.

If strncmp compares upto 'n' chars unless it hits a '\0', it will return a succesful compare for strings like "foo" against "foobar" as it reaches a '\0' after the second 'o' and exits.

So my question is, what is the safest way to compare 2 full strings, returning an incorrect compare if they are not 100% identical.

Test program:

Code:

#include <windows.h>
#include <tchar.h>
#include <stdio.h>

TCHAR Protocols[][5] = {
    _T("IP"),
    _T("ICMP"),
    _T("TCP"),
    _T("UDP")
};

INT _tmain(INT argc, TCHAR *argv[])
{
    INT k;
    TCHAR Proto[5];

    _tcsncpy(Proto, argv[1], sizeof(Proto));
    for (k = 0; k < sizeof(Protocols) / sizeof(Protocols[0]); k++)
    {
        if ( _tcsnicmp( Proto, Protocols[k], _tcslen(Proto) ) == 0)
            _tprintf(_T("match found %s\n"), Protocols[k]);
    }
  
  return 0;
}

Result:

Code:

c:\> test I

match found IP
match found ICMP

This should not match